Trapped in my inner prison-Cross-sectional examination of internal and external entrapment, hopelessness and suicidal ideation.

BACKGROUND: Within the integrated motivational-volitional model of suicidal behavior, entrapment that consecutively leads to hopelessness is considered as a proximal risk factor for suicidal ideation. Entrapment can refer to both external and internal circumstances whereby results of recent studies indicate that internal entrapment plays a more important role than external entrapment in the development of suicidal ideation. It has been considered that to escape internal entrapment might be more complicated than to change external circumstances. However, it remains unclear whether the greater effect of internal entrapment on suicidal ideation is due to greater feelings of hopelessness. Therefore, the aim of this study was to address this research gap and to examine the effects of internal and external entrapment on hopelessness and suicidal ideation.
METHODS: N = 454 participants from a community sample (75% female) aged between 18 and 73 years (M = 29.91, SD = 11.56) conducted a cross-sectional online survey. All participants were assessed for suicidal ideation, hopelessness, and internal as well as external entrapment. Pearson product-moment correlations and two mediation analyses were conducted.
RESULTS: All constructs were significantly correlated. For both internal and external entrapment, an effect on suicidal ideation was found. Both effects were partially mediated by hopelessness, this mediation was larger for external entrapment. The completely standardized indirect effect used to compare the mediation models was larger for external entrapment than for internal entrapment.
CONCLUSIONS: Hopelessness mediated the association between external entrapment as well as internal entrapment and suicidal ideation. This effect was larger for external entrapment.

Background

Everyone knows the feeling of being trapped due to external or internal circumstances [1]. The loss of one’s job, an argument in a relationship, or financial problems can lead to the feeling that there is no way out and that we are caught in a situation. The same applies to internal circumstances, for example, through thoughts that we believe we cannot control. Entrapment has been associated with depression [2] but has also come to the fore as a potentially important proximal risk factor for suicidal ideation. One of the current ideation-to-action theories that seeks to explain the development of suicidal ideation and the transition to suicidal behavior is the Integrative Motivational-Volitional Model [3]. The model consists of three phases whereby the first phase focuses on the individual’s biopsychosocial context, a person’s genetic, cognitive vulnerabilities, and a person’s negative life events as well as environmental influences. The second phase proposes that feelings of defeat and humiliation lead to entrapment, which in turn facilitates suicidal ideation. Additional “threat-to-self” as well as “motivational” moderators influence the transitions from defeat to entrapment and from entrapment to suicidal ideation. The third phase of the IMV model describes the actual transition from suicidal ideation to suicidal behavior. This transition is again influenced by “volitional” moderators such as the capability for suicide [4].

Within the frame of the IMV model, entrapment plays a central role in the development of suicidal ideation. This central role of entrapment could be shown by a tremendous amount of research. Branley-Bell, O’Connor [5] showed in a prospective study with N = 299 adult participants that defeat had an indirect effect on suicidal ideation through entrapment. Park, Cho [6] pointed to entrapment as a risk factor–even superior to relatively robust risk factors such as depression–for suicidal ideation in a cross-sectional study with more than 11,000 students from South Korea. The effect of entrapment on suicidal ideation and the subordinated role of defeat could also be demonstrated by several other studies [7-10].

Even though Gilbert and Allan [1] originally proposed entrapment as a two-dimensional construct, the IMV model does not explicitly differentiate between internal and external entrapment. However, Forkmann, Teismann [11] demonstrated by means of network analysis the two dimensional structure of entrapment. Recent research additionally revealed that internal entrapment seems to be more important in the development of suicidal ideation than external entrapment [9]. Owen, Dempsey [12] verified in their prospective longitudinal designed study, that the subtypes of entrapment have differential effects on suicidal ideation. Only internal but not external entrapment mediated the relationship between defeat and suicidal ideation in a sample of 80 adults with bipolar disorder. Höller, Rath [13] showed in a prospective study with a sample at high-risk of suicide that only internal entrapment could predict suicidal ideation but not external entrapment. O’Connor and Portzky [9] and Rasmussen, Fraser [8] stated that internal entrapment might be more difficult to modify deliberately for an individual than external entrapment, which then could lead in turn to more intense feelings of hopelessness which then entail heightened suicidal ideation. Contrary, Lucht, Höller [14] demonstrated a simple mediation of the relationship between defeat and suicidal ideation via both internal and external entrapment. So far, it remains unclear how, why and to what extent internal and external entrapment influence suicidal ideation.

A construct that appears to be closely related to entrapment is hopelessness, which also has been shown to be a risk factor for suicidal ideation [15]. The Cry of Pain Modell [16] assumes that insufficient escape routes or options for action lead to feelings of entrapment, which then might lead to hopelessness because there seems to be no way out of the circumstances. As a consequence this can then lead to suicidal ideation. Johnson, Gooding [17] described that hopelessness develops from entrapment. Since O’Connor and Kirtley [3] only exemplarily name motivational moderators and additionally emphasize that moderators might also function as mediators of the proposed relations between the concepts in their model, hopelessness could be a variable that mediates the relationship between entrapment and suicidal ideation in the motivational phase of the model. This assumption is substantiated by findings of Littlewood, Gooding [18] showing that hopelessness mediates the association between entrapment and suicidality, but they did not differentiate between internal and external entrapment. Individuals might experience internal and/or external entrapment, which leads to hopelessness and then to suicidal ideation.

Even though, due to the different effects of internal and external entrapment on suicidal ideation that have been reported empirically in the mentioned studies, a differential impact of these constructs on hopelessness seems plausible considering the idea that the escape from external circumstances might be easier [8, 9]. However, this has not yet been investigated. Thus, we hypothesized that 1) internal and external entrapment, hopelessness and suicidal ideation correlate significantly but that the correlations are greater for internal than for external entrapment and 2a) both the effect of internal and external entrapment on suicidal ideation is partially mediated by hopelessness but 2b) this association is greater mediated by hopelessness for internal entrapment.

Methods

Procedure

Data was collected from April 2021 to July 2021 in a cross-sectional online survey that was conducted on www.soscisurvey.com. Participants were recruited through advertisement at the University of Duisburg-Essen as well as social media (e.g., Facebook). Before starting the survey, participants were informed about the purpose of the study, the voluntary nature of participation, data storage and security, and gave informed consent by accepting the conditions on the first page of the online survey. In case participants did not agree, the participation in the study was not possible and the window was closed. Inclusion criteria were an age above 18 years and sufficient knowledge of the German language. In addition, only those persons who answered the attention check item correctly were considered in the analysis. The attention check item asked participants to check the answer option “4”. In case they did not check this item correctly due to inattentiveness, they were excluded from analyses.

The study was approved by the Ethic Committee of the University of Duisburg-Essen and was in accordance with the Declaration of Helsinki [19].

Measures

In order to gain insight into any past and current mental disorders of the participants, they were asked with one item each whether they had a mental disorder in the past or at the moment and whether they were receiving treatment.

In the following, all measures relevant for this study will be reported.

Internal and external entrapment

To assess internal and external entrapment, the entrapment scale (ES; [1]; German version: [20]) was used. The ES consists of 16 items, whereby six items assess internal entrapment (“I would like to escape from my thoughts and feelings”) and ten items assess external entrapment (“I am in a relationship I cannot get out of”) referring to the last week. Each item must be answered on a 5-point Likert Scale ranging from 0 = not at all to 4 = very strong. A sum score was calculated for each of the two subscales. Internal consistencies have been shown to be good (Cronbach’s α ≥ .84) [1, 20]. For this sample, internal consistency was excellent for both internal (Cronbach’s α = .96) and external entrapment. (Cronbach’s α = .91).

Suicidal ideation

Suicidal ideation has been measured using the Beck Scale for Suicidal Ideation (BSS; [21]; German version: [22]), a 21-item self-report measure assessing suicidal ideation (SI) on a 3-point scale from 0 to 2 with differing item phrasing. When participants answered items 4 and 5 (screening items) with at least 1, the first 19 items were used to build a sum score. Otherwise, participants had a sum score of zero. The items 20 and 21 describe intensity and frequency of former suicide attempts and are not part of the sum score. Since there is an ongoing discussion on the factor structure of the BSS [23], only the sum of the first five items were used as a screener for suicidal ideation (BSS-Screen), which has been shown to have good scale properties and excellent internal consistency (Cronbach’s α = .97) [24]. In this sample, internal consistency was also excellent with Cronbach’s α = .91.

Hopelessness

The Beck Hopelessness Scale (BHS; [25]; German version: [26]) includes 20 true-false items that assess pessimistic and hopeless cognitions (“I might as well give up, because there is nothing I can do to improve the situation”). The BHS is also evaluated via a sum score, while higher scores indicate higher levels of hopelessness. Validity and reliability of the German version of the BHS has been shown in prior studies [26]. Internal consistency in the current sample was excellent with Cronbach’s α = .92.

Statistical analyses

All statistical analyses were conducted with SPSS version 27.0. For the first hypothesis that all constructs are correlated but that correlations are higher for internal than for external entrapment, person product-moment correlations were calculated. Correlations ≥ 30 were considered as moderate and correlations ≥ .50 were considered as strong correlations [27]. To test whether the correlation coefficients significantly differed, correlation coefficients were adjusted with Fisher’s z transformation and the calculator of Hemmerich [28] was used. Since the correlation coefficients were based on the same sample and had the same variable (BSS-Screen) in common, the significance for dependent groups with a third variable was calculated. The z-scores were compared with the critical z-score of 1.645 (5%-level for one-sided testing). For a significant difference, the z-score had to be higher than the critical z-score.

For the second hypothesis, two mediation analyses were conducted using SPSS-Macro PROCESS version 3.5 [29]. Mediation model 1 included internal entrapment as the predictor (X), hopelessness as the mediator (M) and suicidal ideation as the dependent variable (Y). Mediation model 2 only differed in including external instead of internal entrapment as the predictor (X). The total effect (the sum of direct and indirect effects (c), the indirect effect, which is the product of the effect of X on M (a) as well as of M on Y (b) were examined [30]. The effect from X on Y in consideration of M (c‘) was examined. We expected this effect to be at least smaller than c (partial mediation). Additionally, we examined whether the indirect effect (ab) became significant [31]. We differentiated between the direct effect from X to Y (c‘), the indirect effect (ab) and the total effect (c = c‘+ab) (see Fig 1). Post- hoc, we conducted a third mediation model with total entrapment (internal and external entrapment as the predictor). Results of this can be found in the Fig 1, Tables 2 and 3 in S1 File.

Fig 1

Mediation model 1 with internal entrapment as predictor.

For all analyses, 5,000 bootstrap iterations were selected. For all effects, completely standardized effect sizes (CS), which express the respective effects in units of standard deviation, were additionally calculated. Higher values correspond to larger effects. The determination coefficient R2 was also calculated. R2 expresses, how much of the variance of the dependent variable is due to the independent variable [32]. Following Cohen [27], R = .02 is considered a weak, R = .13 a moderate, and R = .26 a large effect. Additionally, standard estimation error (SE) as well as significance of the entire model (F-Test) [33] will be reported.

Results

Sample

N = 636 persons (70% female) participated in a cross-sectional online survey. Four hundred fifty-four participants (75% female) between 18 and 73 years old (M = 29.91, SD = 11.56) were included in the present analyses because they filled out all relevant measures and answered the attention check item correctly. Of those, 272 participants (60%) were in a relationship, 167 participants (37%) reported a mental disorder in the past, and 138 (39%) reported a current mental disorder from whom 110 (80%) were currently in therapeutic treatment. Forty-two participants (9%) reported a suicide attempt in their past. Suicidal ideation in the past two weeks was reported by 98 participants (22%). One hundred twenty-five (28%) participants were students. More specific sociodemographic characteristics can be found in the S1 File.

Correlation analysis

Regarding the first hypothesis, internal, external entrapment, hopelessness, and suicidal ideation were significantly correlated (r ≥ .50, p < .01; see Table 1). The correlation between suicidal ideation and internal entrapment was significantly stronger than between suicidal ideation and external entrapment (z = 3.422, p < .001). Additionally, hopelessness was significantly stronger correlated with internal than with external entrapment (z = 2.818, p < .002).

Table 1

Descriptive statistics and Pearson product-moment correlations.

	M	SD	SE	Range	Med.	Skew.	Kurt.	1. IE	2. EE	3. BHS
1. IE	8.36	8.28	.39	0–24	6	.59	-1.10	˗
2. EE	13.17	9.81	.46	0–40	11	.49	-.81	.85**	˗
3. BHS	6.52	5.61	.26	0–20	4	.84	-.55	.73**	.68**	˗
4. BSS-S	1.19	2.23	.10	0–10	0	2.05	3.58	.63**	.56**	.72**

Note. IE = Internal Entrapment Subscale; EE = External Entrapment Subscale; BHS = Beck-Hopelessness-Scale; BSS-S = Beck-Suicidal Ideation-Scale-Screen; M = mean; SD = standard deviation; SE = standard error; Med. = Median; Skew. = skewness of the distribution; Kurt. = kurtosis of the distribution

**p < .01.

Mediation analysis

Regarding the second hypothesis, all coefficients were significant (p < .001). The effect of internal entrapment on suicidal ideation (c = .170, SE = .013) was reduced when hopelessness was taken into account as a mediator (c‘ = .062, SE = .014) as can be seen in Fig 1. The total effect from external entrapment on suicidal ideation (c = .127, SE = .010) was also reduced when hopelessness was taken into account as a mediator (c‘ = .030, SE = .011; see Fig 2).

Fig 2

Mediation model 2 with external entrapment as predictor.

There was an indirect effect from internal entrapment to suicidal ideation, which was mediated by hopelessness (ab = .108, SE = .015, 95%-CI [0.081, 0.138]; see Table 2). The completely standardized indirect effect was CS = .402. Following Cohen [27], all determination coefficients indicate a great amount of explained variance (R > .26) as well as a significant model (p < .001). Internal entrapment explained a large proportion of variance in hopelessness (53.4%); correspondingly, the effect was large with a = .496 (SE = .023). Additionally, explained variance for suicidal ideation increased from 39.8% to 53.9%, when hopelessness was considered as a mediator in this model.

Table 2

Total, direct, and indirect effects of the mediation models.

	Effect	SE	95% CI	CS
Mediation model 1
Total effect	.170	.013	[0.145, 0.195]	.631
Direct effect	.062	.014	[0.034, 0.090]	.230
Indirect effect	.108	.015	[0.081, 0.138]	.402
Mediation model 2
Total effect	.127	.010	[0.107, 0.148]	.561
Direct effect	.030	.011	[0.008, 0.052]	.132
Indirect effect	.097	.012	[0.076, 0.122]	.429

Note. Mediation model 1: internal entrapment (X), hopelessness (M), suicidal ideation (Y); mediation model 2: external entrapment (X), hopelessness (M), suicidal ideation (Y); SE = standard estimation error; 95% CI = 95% confidence interval; CS = complete standardized effect.

There was also an indirect effect from external entrapment on suicidal ideation, which was mediated by hopelessness (ab = .097, SE = .012, 95%-CI [0.0757, 0.01217]). The completely standardized indirect effect was CS = .429 and therefore descriptively slightly larger than the effect of internal entrapment on suicidal ideation. The explained variance through external entrapment was slightly lower with 46.8% than in internal entrapment (53.4%). Additionally, explained variance for suicidal ideation increased from 31.5% to 52.3%, when hopelessness was considered as a mediator in the model. This means that the consideration of hopelessness in the mediation model with external entrapment (change in R2 = .208) could explain more variance than in the mediation model with internal entrapment (change in R2 = .141). All determination coefficients including standard estimation errors and F-tests can be found in Table 3.

Table 3

Regression coefficients for the prediction of suicidal ideation.

Predictor		Predicted Variables
		M (BHS)				Y (BSS-S)
		Coefficient	SE	p		Coefficient	SE	p
X (IE)	a	.496	.023	< .001	c	.170	.013	< .001
		R2 = .534				R2 = .398
		F (1, 452) = 462.826, p < .001				F (1, 452) = 181.494, p < .001
					c’	.062	.014	< .001
M (BHS)		˗	˗	˗	b	.218	.026	< .001
Constant	i1	2.376	.202	< .001	i2	-.744	.078	< .001
X + M						R2 = .539
						F (2, 451) = 130,088, p < .001
X (EE)	a	.392	.019	< .001	c	.127	.010	< .001
		R2 = .468				R2 = .315
		F (1, 452) = 425.563, p < .001				F (1, 452) = 150.183, p < .001
					c’	.030	.011	.008
M (BHS)		˗	˗	˗	b	.249	.026	< .001
Constant	i1	1.363	.240	< .001	i2	-.823	.089	< .001
X + M						R2 = .523
						F (2, 451) = 120.997, p < .001

Note. IE = internal entrapment subscale; EE = external entrapment subscale; BHS = Beck-Hopelessness-Scale; BSS-S = Beck-Suicidal Ideation-Scale-Screen.

Discussion

This study aimed at examining the differential relation between internal and external entrapment and suicidal ideation and investigated whether this relation is (partially) mediated by hopelessness. Prior studies showed that internal entrapment might be more important than external entrapment in the development of suicidal ideation [12, 13]. However, it has not yet been examined why this might be the case. As stated by Rasmussen, Fraser [8], internal entrapment can lead to more hopelessness which in turn can lead to more suicidal ideation than external entrapment. This follows the assumption that internal entrapment might to be more difficult to modify than external entrapment. Due to the immutability, greater feelings of hopelessness might appear. Therefore, hopelessness as a possible mediator for the association between internal entrapment and suicidal ideation could serve as a potential explanation for differential relations between internal and external entrapment and suicidal ideation. We hypothesized that 1) internal and external entrapment, hopelessness and suicidal ideation significantly correlate but that the correlations are larger for internal entrapment than for external entrapment and 2a) both the effects of internal and external entrapment on suicidal ideation are partially mediated by hopelessness but 2b) this association is greater mediated by hopelessness for internal entrapment.

Results support our first hypothesis, showing strong correlations between internal and external entrapment, hopelessness, and suicidal ideation. As expected, the correlation between internal entrapment and suicidal ideation was stronger than the correlation between external entrapment and suicidal ideation. The same applies to hopelessness, which was stronger correlated with internal than with external entrapment. These findings are in line with Lester [34], who reported descriptively a larger correlation coefficient for internal entrapment and hopelessness as compared to external entrapment and hopelessness, too.

In accordance with hypothesis 2a), both the associations between internal entrapment and suicidal ideation as well as external entrapment and suicidal ideation were partially mediated by hopelessness. In this study, the large amount of explained variance in hopelessness through internal entrapment is striking and emphasizes its role in the development of hopelessness. However, it has to be taken into account that those were only cross-sectional results. These findings should be replicated in a clinical sample with longitudinal data. The role of hopelessness is additionally substantiated by the significant mediation effect suggesting that the effects found for internal entrapment on suicidal ideation [9, 14] can to a certain degree be traced back to its effects on hopelessness. The explained variance in suicidal ideation through internal entrapment is smaller, which emphasizes the role of internal entrapment especially for the development of hopelessness and not to such a large amount of suicidal ideation, which is in line with the high correlations we found for hopelessness and internal entrapment. Earlier studies [12, 13] finding effects for associations between internal entrapment and suicidal ideation did not consider hopelessness, which might explain these effects.

Additionally, hopelessness seems to play an underestimated role for external entrapment as well. Hopelessness mediated the association between external entrapment and suicidal ideation to a greater extent than the association between internal entrapment and suicidal ideation. These findings appear to be contrary to earlier findings [13, 14] that could not demonstrate an effect of external entrapments on suicidal ideation but only for internal entrapment. Also Oakey-Frost, Harris [35] fount that internal but not external entrapment moderated by fearlessness about death could explain the relationship between PTSD and suicidal ideation. Thus, contexts and interindividual differences may be important for the different effects on suicidal ideation. However, the approach differed since we included hopelessness. The findings are still surprising considering arguments that external circumstances might easier be modified than internal entrapment [9, 13]. Still, external entrapment seems to be as much (or maybe even more) associated with hopelessness as internal entrapment. One explanation for this found effect could be the ongoing Covid-19 pandemic. When collecting data from April to July 2021, the pandemic was already ongoing since over a year and vaccinations just started in Germany. Due to several external governmental restrictions in participants’ life feelings of external entrapment and hopelessness could have been increased. On the contrary, Bryan, Bryan [36] could not find support for the assumed correlation of physical distancing measures with increased suicide risk in U.S. adults from March until the beginning of April in 2020. However, as the authors stated [36], their findings need to be cautiously interpreted since their cross-sectional study was designed before the Covid-19 pandemic and was conducted at the very beginning of the U.S. pandemic. Therefore, these findings might indicate that the negative effects of physical distancing had not yet occurred but might have been detected later on. Another reason for the results could be that internal and external entrapment are not as different as assumed [11] and/or are not separable enough from hopelessness. Locus of control could also be relevant regarding all three concepts that should be considered.

Theoretical and practical implications

Given the current results in addition to previous findings, it might be recommendable to consider integrating the differentiation of the subtypes of entrapment into current theories on suicidal ideation, such as the IMV model. Hopelessness, internal as well as external entrapment should be considered and included in clinical risk assessment. The differentiation into internal and external entrapment is not only necessary in regard to the mixed evidence for both constructs but especially because the therapeutic approach for a reduction differs. As mentioned in the study of Oakey-Frost, Harris [35], there might be individual differences responsible for the differential effects of internal and external entrapment but this would make the differentiation even more important to develop interventions for both types. It seems to be important to fulfill individual differences in suicide prevention and risk assessment. Since both external and internal entrapment have been argued as being modifiable [8, 37] the differentiation between internal and external entrapment and, in particular, the need for differently targeted interventions might be important. For internal entrapment the frame of cognitive behavioral therapy seems to be ideal because of the identification and modification of automatic thoughts and beliefs [38, 39]. For external entrapment, behavioral experiments and exposure could be helpful. Those interventions could lead to the feeling of having more control over the external circumstances. This could strengthen participants’ expectations of results and hereby maybe reduce feelings of hopelessness. Presumed hopeless situations or states might then not be received as unchangeable but as surmountable. However, these are only theoretical considerations that need to be substantiated by more research in this area. Additionally, two aspects must be noted: First, there is a difference in treating suicidal ideation and preventing the development of suicidal ideation. There are intervention programs specifically targeting suicidality such as the Collaborative Assessment and Management of Suicidality (CAMS) [40] or the Attempted Suicide Short Intervention Program (ASSIP). Second, even though internal and external entrapment might be treatable with different therapeutic techniques, both constructs often occur simultaneously so in clinical practice it might not be easy to treat and target them separately. CAMS represents a treatment that conceptualizes suicidal “drivers”, which can include both internal and external entrapment. Those drivers can then be implemented in the individual treatment plan including the knowledge of therapists of particular treatment targeting exactly these drivers [41]. Thus, CAMS targets proximal risk factors could be used in clinical practice.

Strengths and limitations

A strength of this study was the relatively large community sample with a percentage of participants with a mental disorder comparable to the 12-months prevalence of mental disorders in Germany [42] and a higher prevalence of suicidal ideation than assumed in the general population [43]. Additionally, the use of an attention check item is a strength since it has been shown that this does not only prevent reckless answering behavior but also increases the motivation of participants [44]. Limitations of the study are that there were no control variables, even though there could be other constructs influencing suicidal ideation, the cross-sectional design of the study with its possible biases in the mediation analyses [45], and that this was not a clinical sample and the question about mental disorders was self-report. Additionally, the sample was very young (M = 29.91), included 75% females and consisted mainly of well-educated persons (41% A-level/general matriculation standard). Compared to the German population (50.7% females [46], M = 44.6 years [47], 33.5% with A-level/general matriculation standard [48]), the generalizability of the study results is limited.

Future research

Future studies should concentrate on clinical samples. Additionally, fluctuations of suicidal ideation, hopelessness, internal, and external entrapment [49, 50] should be considered. Ecological Momentary Assessment (EMA) offers to repeatedly assess participants in their natural environment [51] capturing moment-to-moment relations between all constructs. This might be a possibility to gain a greater understanding of the complex and dynamic interrelations of risk factors for suicide.

Conclusion

This study aimed at gaining a deeper understanding for internal and external entrapment and their associations with suicidal ideation. Hopelessness as one potential mediator of these associations was examined. Results of the study emphasize the role of internal entrapment but also highlight hopelessness as a mediator of the association between external entrapment and suicidal ideation. Internal and external entrapment should necessarily be differentiated in suicide risk assessment since the reduction of both (and thereby the prevention of suicidal ideation) might require different interventions. Future studies should examine whether these results can be replicated longitudinally and in a clinical sample.

(DOCX)

Click here for additional data file.

(XLSX)

Click here for additional data file.

18 Mar 2022

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Pedro Vieira da Silva Magalhaes, M.D., Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf.

2. Please provide additional details regarding participant consent. In the ethics statement in the Methods and online submission information, please ensure that you have specified what type you obtained (for instance, written or verbal, and if verbal, how it was documented and witnessed). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information.

3. Thank you for stating the following financial disclosure:

[This study did not receive funding.]

At this time, please address the following queries:

a) Please clarify the sources of funding (financial or material support) for your study. List the grants or organizations that supported your study, including funding received from your institution.

b) State what role the funders took in the study. If the funders had no role in your study, please state: “The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”

c) If any authors received a salary from any of your funders, please state which authors and which funders.

d) If you did not receive any funding for this study, please state: “The authors received no specific funding for this work.”

Please include your amended statements within your cover letter; we will change the online submission form on your behalf.

4. We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. For more information on unacceptable data access restrictions, please see http://journals.plos.org/plosone/s/data-availability#loc-unacceptable-data-access-restrictions.

In your revised cover letter, please address the following prompts:

a) If there are ethical or legal restrictions on sharing a de-identified data set, please explain them in detail (e.g., data contain potentially sensitive information, data are owned by a third-party organization, etc.) and who has imposed them (e.g., an ethics committee). Please also provide contact information for a data access committee, ethics committee, or other institutional body to which data requests may be sent.

b) If there are no restrictions, please upload the minimal anonymized data set necessary to replicate your study findings as either Supporting Information files or to a stable, public repository and provide us with the relevant URLs, DOIs, or accession numbers. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories.

We will update your Data Availability statement on your behalf to reflect the information you provide.

5. Your ethics statement should only appear in the Methods section of your manuscript. If your ethics statement is written in any section besides the Methods, please delete it from any other section.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thank you for the opportunity to review your manuscript! I am fascinated by the ongoing IMV debate, specifically regarding the specific constructs hypothesized to play a role in suicide phenomenology. This study makes and important contribution thereto and has interesting implications moving forward. However, while this study is standard in its methodological approach, it is also significantly limited by a cross-sectional mediation design and may benefit from the inclusion of an additional mode. Finally, there are several bold but unsubstantiated claims in the manuscript that will require further contextualization, discussion, and most importantly, citation. Please see attached document for full review and comments.

Reviewer #2: Review for manuscript PONE-D-22-04773: Trapped in my Inner Prison – Cross-Sectional Examination of Internal and External Entrapment, Hopelessness and Suicidal Ideation

This is an interesting study. It is limited by a non-clinical cross-sectional sample, although the authors point out these limitations.

Methods

The Sample results (p.5, l. 105-112) should be reported in the Results section.

More information about the sample would be useful, such as education level, socio-economic status, etc. What proportion were students recruited from the University?

Measures

How were past and current mental disorders measured?

The scoring of the BSS is not clearly explained (sentence on p.6, l.136-137). How were the five items which were used scored?

Results

In Table 1 it seems that the Min and Max are the possible min. and max. values for the scale, rather than the results obtained from the sample. These should be the min. and max. values from the sample. If the distributions were very skewed, median and interquartile range should be reported too.

The means obtained for all the psychological measures (Table 1) are fairly low, as this is not a clinical sample. Could the authors please comment on how skewed the distributions were and whether this could have implications for the statistical methods used. Often with non-clinical samples the distributions of psychological scales are extremely skewed.

Discussion

The sentence on p. 12, l. 250-251 makes an inference about the role of internal entrapment on the development of hopelessness, however this is a cross sectional non-directional study.

Although hopelessness mediated the association between external entrapment and suicidal ideation to a slightly greater extent, the results are very similar to those of internal attachment. Because the results are so similar, and without testing for significant differences of the explained variance (R2) and the coefficients, it is difficult to draw a definitive conclusion that one mediation is stronger than the other.

Strengths and Limitations

The authors mention the use of an “attention check item” (p.14, l.294), but this is not included in the Measures section.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: D Nicolas Oakey-Frost

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: PLOS One Review.docx

Click here for additional data file.

20 Apr 2022

Reviewer #1

This is an interesting study. It is limited by a non-clinical cross-sectional sample, although the authors point out these limitations.

Methods

The Sample results (p.5, l. 105-112) should be reported in the Results section.

Response: We consider this sample information necessary to provide insight into the composition of the sample at this point. The sample information is not reported in the results section because the results section should mainly highlight the results of the statistical analyses that were conducted to test our hypotheses (i.e., correlation and mediation analysis). We hope that it is okay if we leave it like that.

More information about the sample would be useful, such as education level, socio-economic status, etc. Response: sociodemographic characteristics are summed up in a table (Table 1 in supplementary material), which can be found in the supplementary material. Information on this table have been added to the participants’ section.

What proportion were students recruited from the University?

Response: The proportion of students from the University of Duisburg-Essen was not measured per se but the proportion of (university) students in general (i.e., irrespective of at which university they were enrolled) was 28% (n= 125). We added this information to the participants’ section.

Measures

How were past and current mental disorders measured?

Response: Participants were asked with single items each whether they had a mental disorder in the past or at the moment and whether they received treatment. We are aware that this is only self-report, this is why we used the wording “participants reported a mental disorder”. We added the self-report nature to the limitations.

The scoring of the BSS is not clearly explained (sentence on p.6, l.136-137). How were the five items which were used scored?

Response: The (total) BSS score ranges from 0 to 38 and is formed from the sum of the first 19 items. The last two items (20 and 21) describe former suicide attempts (and not thoughts) and are usually not included in the total score. However, because of the ambiguous factor structure of the total BSS score, the BSS-Screen was used to describe suicidal ideation. In contrast to the total BSS-Score, the BSS-Screen score has a unidimensional factor structure. This BSS-Screen includes the sum score of only the first five items of the BSS. We added information on this to the manuscript.

Results

In Table 1 it seems that the Min and Max are the possible min. and max. values for the scale, rather than the results obtained from the sample. These should be the min. and max. values from the sample. If the distributions were very skewed, median and interquartile range should be reported too.

Response: Thank you for this suggestion. The “Min” and “Max” were replaced by the range, so it is easier to understand that those are the values from the sample. Information on skewness, kurtosis, range and median have also been added to the table. We hope this meets your expectations.

The means obtained for all the psychological measures (Table 1) are fairly low, as this is not a clinical sample. Could the authors please comment on how skewed the distributions were and whether this could have implications for the statistical methods used. Often with non-clinical samples the distributions of psychological scales are extremely skewed.

Response: We followed your suggestion above and added skewness and kurtosis to the table. Due to the large sample and the fact that bootstrapping does not depend on normal distribution, the skewness and kurtosis has not been considered to impact validity of the results any further.

Discussion

The sentence on p. 12, l. 250-251 makes an inference about the role of internal entrapment on the development of hopelessness, however this is a cross sectional non-directional study.

Response: You are completely right, that this is a limitation and. We changed the wording and added the limitations of the study, so it now reads like this: “In this study, the large amount of explained variance in hopelessness through internal entrapment is striking and emphasizes its role in the development of hopelessness. However, it has to be considered that those were only cross-sectional results. These findings should be replicated in a clinical sample with longitudinal data.” We hope that this meets your expectations.

Although hopelessness mediated the association between external entrapment and suicidal ideation to a slightly greater extent, the results are very similar to those of internal attachment. Because the results are so similar, and without testing for significant differences of the explained variance (R2) and the coefficients, it is difficult to draw a definitive conclusion that one mediation is stronger than the other.

Response: We agree. However, Internal and external entrapment being so similar in its effect on hopelessness / SI is still surprising considering previous findings in which internal entrapment seems to have a more important role with regard to suicidality (Höller et al., 2021; O’Connor & Portzky, 2018; Owen et al., 2018; Rasmussen et al., 2010) . Indeed, it is a limitation that there was no testing for significance of the explained variances, coefficients and standardized effects. Anyway, the completely standardized effect is a proper measure to compare effects from different mediation models (Hayes, 2017), the size of the effect itself is already a surprising and relevant result.

Strengths and Limitations

The authors mention the use of an “attention check item” (p.14, l.294), but this is not included in the Measures section.

Response: The attention check item is already mentioned in the Methods (sample) section. We decided not to repeat this information in the measures section, as this item only served to filter out those people who completed the survey responsibly. Therefore, the attention check item is not a measurement per se. Participants who did not correctly answer the attention check item were excluded from the data analyses. We added the following sentences to the manuscript: “The attention check item asked participants to check the answer option “4”. In case they did not check this item correctly due to inattentiveness, they were excluded from analyses.” In the participants section is statet that 454 participants answered the attentiom check item correctly and completed all relevant questionnaires. We hope this answers your question.

Reviewer #2

Thank you for the opportunity to review your manuscript! I am fascinated by the ongoing IMV debate, specifically regarding the specific constructs hypothesized to play a role in suicide phenomenology. This study makes and important contribution thereto and has interesting implications moving forward. However, while this study is standard in its methodological approach, it is also significantly limited by a cross-sectional mediation design and may benefit from the inclusion of an additional mode. Finally, there are several bold but unsubstantiated claims in the manuscript that will require further contextualization, discussion, and most importantly, citation:

General comments:

I do understand and appreciate that the authors may consider English as a second language. However, there were points where the narrative was unclear and could benefit from copyediting. I was able to understand the thrust, but re-reading and re-evaluating readability will help make the manuscript clearer for the reader.

Response: The manuscript was additionally proofread, we hope that this now meets your expectations.

The authors should refrain from using the term “confirmed” when referencing their own hypotheses or the results of extant literature. The nature of parametric statistics precludes the confirmation of results and only support for the observed results.

Response: The corresponding phrase (line 249) was changed to “Results support for…”. We additionally searched the manuscript for the term “confirm” and changed it when used inappropriately. Now the word confirmed is only used for other studies. We did not mean to confuse the reader or to give wrong information.

Background

Generally, when introducing a cited study please briefly describe the sample and the design of the cited study. This will give the reader more context for the results being described

Response: Short information about the design and sample of the cited studies was added.

Lines 73 – 74 will require a citation for the assertion that “research...has revealed that internal entrapment seems to be more important...”

Response: We are sorry, there was a reference missing. This information came from O'Connor & Portzky (2018). We added this citation/reference.

Please briefly describe the findings of Owen, Dempsey et al., more in depth

Response: Information about the responding design and sample of this study was added, as well as its outcome distinguishing between internal and external entrapment.

Lines 78 – 79 appears to be an assertion that comes out of the blue; however, it becomes clearer when discussing this assertion in the Discussion section of the manuscript, lines 230 – 233. Clarifying this assertion in the Introduction would be useful

Response: The explanations made in the discussion have been added to the Introduction. We hope everything is now easier to understand.

Line 97; although I understand the reflex to argue from a perspective of reason, it is not sufficient to argue for the differential effects of entrapment dimensions on hopelessness based on reason; reasonable based on...? The Cry of Pain model? Johnson, Gooding? These at least should be cited and expanded upon a bit more

Response: The word “reasonable” was changed to “conceivable” to support the theoretical assertion which was made according to the empirical findings mentioned above. We also added that this assumption is based on the above mentioned studies and considerations.

Measures

Please provide a detailed breakdown of demographics in a table to further contextualize the sample; among the variables already include, likely additions should include racial identity, gender identity, and the baseline risk variables (suicide attempt, suicidal ideation, etc.)

Response: We already give information on suicide attempt in the past as well as suicidal ideation and gender identity. However, we also added a table (Table 1 in supplementary material) including some more sociodemographic characteristics and risk variables as supplementary material. We hope that this meets your expectations. However, there is no information on racial identity; it is not common to assess this in Germany.

Please provide further detail as to whether measures were sum scored or mean scored

Response: all measures were sum scored, which has been added to the descriptions.

Please provide the following estimates in the correlation table in addition to those provided: standard error (SE), skew, kurtosis, range, for each of the constructs measured

Response: The missing information has been added to Table 1 in the manuscript.

Statistical analyses

Line 165; the assertion of either full or partial mediation is contrary to the hypotheses and strikes of HARKing; please clarify here and in the hypotheses whether you predict full or partial mediation, not both.

Response: The part of the sentence in which the full mediation was mentioned was deleted to clarify our partial mediation hypothesis. We apologize for this inconvenience. We do not know how this happened; it might have happened during the translation process but we clearly did not conduct HARKing, which is quite a strong accusation. Our hypotheses were formulated before data collection even began.

It seems reasonable that the authors should test the hypothesized model with the Entrapment Scale total score considering their intention to determine whether internal vs. external entrapment explain more variance in SI as explained by hopelessness; this would make for a potentially stronger paper by match some of their cited literature (i.e., Littlewood, Gooding), testing an inference of the IMV, and align with their assertion that “it remains unclear how and why internal and external entrapment influence suicidal ideation”. Testing all three models would permit more nuanced discussion of theoretical implications.

Response: Our intention above all was to investigate the difference between internal and external entrapment relating to suicidal ideation and hopelessness. The missing differentiation of internal and external entrapment in the IMV model was one of our motivations for this research. Along with our hypotheses, we expected the effect of internal entrapment to be greater. To examine our hypotheses it was necessary to conduct the models separately for internal and external entrapment. Due to your suggestions, we conducted post-hoc a third mediation model including total entrapment as a predictor. We added these post-hoc analyses to the statistical analyses section and provide the results in the supplementary material. All coefficients were significant (p < .001. Overall, when comparing the results of total entrapment to those of the preceding analyses, the completely standardized indirect effect of total entrapment was smaller than the completely standardized indirect effect of external entrapment (for more detailed results see supplementary material. This suggests that the role of external entrapment needs to be further examined independently of internal entrapment especially because despite the statistics the treatment differs (s. comment below).

Discussion

Line 263; please compare and contrast how your findings are contrary to those of the cited studies

Response: Our findings are contrary to those of Höller et al. (2021) and Lucht et al. (2020), as our results show an effect of external entrapment on suicidal ideation. We added discussion on this topic to the manuscript.

Lines 267 – 274; these are major assumptions regarding the impact of the COVID-19 pandemic on suicidal ideation and external entrapment that will require contextualization within the available literature. For example, Bryan, Bryan, and Baker (2021) found no relationship between physical distancing and with worse mental health outcomes. This observation has implications for the relationship between the COVID-19 pandemic and external entrapment.

Response: Thank you for this suggestion. Unfortunately, we cannot find the paper you mentioned and are therefore not exactly sure what you mean. If you could specify, we would be happy to adapt the manuscript accordingly. Physical distancing is not the same as feeling externally entrapped because of the governments’ social distancing rules. Feeling entrapped in this case does not necessarily mean to actually be trapped in the sense of physical distance but more the feeling of being trapped due to the rules and no hope that this will change any time in the near future. But we could further adapt the manuscript to the paper on physical distancing when we know which paper exactly you mean. We made some changes to weaken our conclusions and hope this meets your expectations now.

Line 278; given that both external and internal entrapment in relation to suicidal ideation were significantly explained by hopelessness to some extent, I am not convinced that these constructs require separation.

Response: Both internal and external entrapment were mentioned here to emphasize the connection with suicidal ideation and hopelessness. We added one more sentences on the differentiation of internal and external entrapment. We are not sure whether we understand your point correctly. Statistically, internal and external entrapment are highly correlated but yet distinct constructs. In this study, the correlation between internal and external entrapment is high with .85. However, the entrapment scale was designed to assess both internal and external entrapment and study results that examined differences in internal and external entrapment found different associations of the constructs with suicidal ideation. There is a difference whether your patient has rumination (internal entrapment) or whether he/she is hopeless due to external circumstances (job loss, relationship problems �  external entrapment). The two constructs measure different states that need different treatment approaches. Those treatment approaches have been discussed in the discussion section, too. The separation of these constructs is only a consequence of the mixed findings. Even if both were equally important in the development of suicidal ideation, the interventions would differ. For clinical practice and for suicide prevention, this needs to be considered. Both construcs are important in the development of suicidal ideation but it would be interesting to investigate how different treatment approaches could prevent individuals from developing suicidal ideation.

Their conclusions may be supported by inclusion of the proposed total score model. If a worse model fit is observed in contrast to the internal or external entrapment models, this conclusion would be significantly strengthened

Response: We foresee from a third model since this was not our goal. Our goal was to examine differential effects from internal and external entrapment on suicidal ideation. Especially because this differentiation is especially important when talking about possible interventions see our comment above. However, we did follow your suggestion and added a third model to the manuscript. This is mentioned as post-hoc analysis in the statistical anylses section. Results can be found in the supplementary material.

Additionally, the authors may wish to discuss the findings in different contexts; for example, they may wish to reference the findings of Oakey-Frost et al., 2021 who found that internal but not external entrapment with fearlessness about death explained the relationship between PTSD and suicidal ideation. Thus, the effect of one vs. the other may vary according to important interindividual differences

Response: These important findings were added to the manuscript. Thank you for this suggestion. However, we would like to mention, that, in our view, this underlines again the importance of differentiating between these constructs. Even if both constructs were equally important, the importance might differ depending on interindividual differences. Maybe there is no “one fits all”-model.

:

Lines 279 – 278; the argument for differential treatment approaches for internal and external entrapment is potentially reasonable, but unsubstantiated with regard to approaches to external entrapment specifically.

Response: In fact, there are no evidence-based interventions yet. That is why we provide some theoretical considerations here. We added a sentence that those are only theoretical considerations and that more empirical research in this area is needed.

Additionally, the question must be asked: are we aiming to improve entrapment or suicidal thoughts and behaviors? Other viable treatment options do exist and should be discussed; The Collaborative Assessment and Management of Suicidality (CAMS; Jobes, 2017) is a framework used to target entrapment OR internal vs. external entrapment as the driver of suicidal thoughts and behaviors based on the needs of the individual in question. This critique includes lines 311 – 312. Thus, the authors may be correct that internal vs. external entrapment may require different approaches based on the needs of the individual and their suicidal driver. But this claim has to be substantiated with citation and discussion.

Response: We are aware that there are intervention programs for patients regarding suicidality but as you said there is a difference of treating suicidality and focusing on proximal risk factors. Intervention targeting proximal risk factors would aim at preventing patients from even developing suicidal ideation. We added reference to the CAMS to the manuscript. We added discussion on this to the manuscript. We also added to the manuscript that we have to differentiate between programs that treat suicidality and interventions that target proximal risk factors. We hope that this meets your expectations now.

Finally, the authors should discuss the limitations of cross-sectional mediation in the context of Maxwell & Cole, 2007.

Response: Maxwell, Cole and Mitchell (2011) was added to the limitations as this article discusses partial mediation models in cross-sectional studies. Thank you for this suggestion.

Figure

I would prefer that arrows in the models are bidirectional. While the conclusions may be theoretically supported, inferring directionality and therefore temporal relationships is not supported in cross-sectional mediation models.

Response: We amended the mediation models but hope that this is not misleading.

Thank you for allowing me to review your manuscript and for your valuable contribution to the suicide prevention literature base. I hope that my comments and feedback are of value to the authors and to the editor(s) of the journal. I genuinely appreciate the opportunity to engage in this valuable scientific discourse.

Höller, I., Rath, D., Teismann, T., Glaesmer, H., Lucht, L., Paashaus, L., Schönfelder, A., Juckel, G., & Forkmann, T. (2021). Defeat, entrapment, and suicidal ideation: Twelve‐month trajectories. Suicide and Life‐Threatening Behavior.

O’Connor, R. C., & Portzky, G. (2018). The relationship between entrapment and suicidal behavior through the lens of the integrated motivational–volitional model of suicidal behavior. Curr Opin Psychol, 22, 12-17. https://doi.org/10.1016/j.copsyc.2017.07.021

Owen, R., Dempsey, R., Jones, S., & Gooding, P. (2018). Defeat and entrapment in bipolar disorder: exploring the relationship with suicidal ideation from a psychological theoretical perspective. Suicide and Life‐Threatening Behavior, 48(1), 116-128. https://doi.org/10.1111/sltb.12343

Rasmussen, S. A., Fraser, L., Gotz, M., MacHale, S., Mackie, R., Masterton, G., McConachie, S., & O'Connor, R. C. (2010, 3/2010). Elaborating the cry of pain model of suicidality: Testing a psychological model in a sample of first-time and repeat self-harm patients. British Journal of Clinical Psychology, 49(1), 15-30. https://doi.org/10.1348/014466509X415735

Submitted filename: Detailed_Responses_to_the_Reviewers.docx

Click here for additional data file.

13 May 2022

14 Jun 2022

Reviewer #1

Many thanks to the authors for their thoughtful responses to the feedback. I have just a few more comments that I think would be best addressed prior to publication:

Background

Line 61, 64, and 67 use the word “confirm[ed]” in relation to the results of the cited studies. I don’t want to sound like a broken record, but “confirming” entrapment as a risk factor in a cross-sectional mediation analysis is a mischaracterization. I think it is incredibly important to not overstate the implications of any results, especially to the general public.

Response: We are sorry that you got the impression we wanted to overstate the findings. To not overrate the results of the cited study the term “confirmed” was changed into “shown” (line 61), “pointed to” (line 64) and “demonstrated” (line 67/70).

Discussion

In previous feedback, the authors indicated their willingness to discuss differential findings with relation to social distancing and external entrapment in the context of the COVID-19 pandemic. Unfortunately, I provided the wrong year for the citation I included. Would the authors be willing to Discuss their findings from Lines 287 – 297 in the context of the following citation:

Bryan, Bryan, & Baker. (2020). Associations among state-level physical distancing measures and suicidal thoughts and behaviors among U.S. adults during the early COVID-19 pandemic. Suicide and Life-Threatening Behavior.

Response: This reference was added to the manuscript (lines 294-300). We discussed the findings of Bryan et al. (2020) that there were no correlations between physical distancing and suicidal ideation, however, as the authors state themselves, they collected data at the very beginning of the pandemic, while we collected data when the pandemic was already going on for more than a year.

To first put the following comment in context, I apologize if my previous feedback was not clearly articulated. I want to be clearer about where I am coming from:

Line 310, their assertion that “there have been no evidence-based interventions for the reduction of entrapment” is where I would recommend, they discuss CAMS. CAMS targets suicidal ideation and suicidal behavior via conceptualization of the patient’s “drivers” which indeed may include perceptions of internal entrapment and/or external entrapment. The clinician then uses their knowledge to recommend particular treatment orientations to target the driver. Thus, treating suicidal ideation occurs via treatment of the factors that lead to suicidal ideation. Additionally, they argue that CAMS and ASSIP do not target proximal risk; from a CAMS perspective, it does. The first session of CAMS includes collaborative formulation of a Safety/Crisis Prevention Plan; these interventions are inherently designed to target “proximal risk” (Line 323).

Response: CAMS is now named to be an effective treatment that is addressing internal and/or external entrapment. We extended the paragraph on CAMS starting on line 334-340. We hope that this meets your expectations.

In essence, I agree with the authors: internal vs. external entrapment may be differentiated based on their treatment needs. I also believe the authors have a good opportunity to make their argument in the context of available interventions. Treatment may be accomplished via CAMS which, again, identifies a driver (e.g., internal entrapment) and then uses patient specific interventions to target the driver (e.g., cognitive therapy [see Jobes, 2017]).

Response: We agree with you that is why we added CAMS as a possible treatment (See comment above)

Overall, I genuinely appreciate the author’s responses and persistence thus far. Thank you again for the opportunity to review your manuscript.

Reviewer #2

The authors have responded to comments and improved the paper. Just some minor comments remain.

Methods

The Sample results (p.5, l. 105-112) should be reported in the Results section.

Response: We consider this sample information necessary to provide insight into the composition of the sample at this point. The sample information is not reported in the results section because the results section should mainly highlight the results of the statistical analyses that were conducted to test our hypotheses (i.e., correlation and mediation analysis). We hope that it is okay if we leave it like that.

Reviewer response: The standard is to report the details of the collected sample in the Results, rather than the Methods.

Response: We think that this actually depends on the journal but we understand where you are coming from so we followed your suggestion. The information of the sample results is now reported in the Results section. The sub-headlines “Correlation Analysis” and “Mediation Analysis” have been added to the Results section to obtain a better structure.

Measures

How were past and current mental disorders measured?

Response: Participants were asked with single items each whether they had a mental disorder in the past or at the moment and whether they received treatment. We are aware that this is only self-report, this is why we used the wording “participants reported a mental disorder”. We added the self-report nature to the limitations.

Reviewer response: The details about this question should be included in the Measures section.

Response: The information delivered above was added to the Measures section.

The scoring of the BSS is not clearly explained (sentence on p.6, l.136-137). How were the five items

which were used scored?

Response: The (total) BSS score ranges from 0 to 38 and is formed from the sum of the first 19 items. The last two items (20 and 21) describe former suicide attempts (and not thoughts) and are usually not included in the total score. However, because of the ambiguous factor structure of the total BSS score, the BSS-Screen was used to describe suicidal ideation. In contrast to the total BSS-Score, the BSS-Screen score has a unidimensional factor structure. This BSS-Screen includes the sum score of only the first five items of the BSS. We added information on this to the manuscript.

Reviewer response: The sentence on p.7, l. 148-149 of the revised manuscript is still unclear English and needs editing: “The first 19 items are summed up in case items 4 and 5 have been answered at least 1.”

Response: We are sorry the reformulation did not meet your expectation. We tried again and also asked an independent person whether it is understandable how the sum score was build. The sentences now read like this in the manuscript: When participants answered items 4 and 5 (screening items) with at least 1, the first 19 items were used to build a sum score. Otherwise, participants had a sum score of zero.

In addition to the above points, a further limitation of the study is that respondents tended to be predominantly young, and perhaps with a large proportion of university and tertiary educated persons, although this will depend on what the standard for Germany is. A brief comment on how the sample compares to the German population may be useful.

Response: Information of the German population was added to the Strengths and Limitations – Section (lines 347-351). We emphasized that our sample includes a higher female percentage, is younger, and a higher percentage of high education than the general German population. We also stated in the limitation section that this limits the generalizability of our findings.

Another comment I have is that internal and external entrapment are so highly related that they would likely often occur together and may not be always easy to separate or be treated separately in psychological interventions.

Response: Indeed, internal entrapment and external entrapment are highly related and often occur together. We modified the discussion and emphasize that it might not be easy to separate them in clinical practice and added more to the treatment program CAMS that targets both internal and external entrapment.

Submitted filename: DetailedResponsetotheReviewes_Revision_Nr_2.docx

Click here for additional data file.

22 Jun 2022

Trapped in my Inner Prison – Cross-Sectional Examination of Internal and External Entrapment, Hopelessness and Suicidal Ideation

PONE-D-22-04773R2

Dear Dr. Höller,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Pedro Vieira da Silva Magalhaes, M.D., Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

5 Jul 2022

PONE-D-22-04773R2

Trapped in my Inner Prison – Cross-Sectional Examination of Internal and External Entrapment, Hopelessness and Suicidal Ideation

Dear Dr. Höller:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Professor Pedro Vieira da Silva Magalhaes

Academic Editor

PLOS ONE