Identity disturbance and substance-dependence in patients with borderline personality disorder.

BACKGROUND: Identity disturbance is one of the DSM-IV criteria for borderline personality disorder, but there has been little attention to its nature. Four subsets of identity disturbance (role absorption, painful incoherence, inconsistency and lack of commitment) have been assessed. This study aimed to assess the role of these subsets in patients with borderline personality disorder and to examine the relationship between identity disturbances and substance-dependence.
METHODS: This case-control study was conducted on 40 patients with borderline personality disorder who were referred to Shahid Beheshti Hospital in Kerman from 2004 to 2005 and 40 healthy people who were matched with the case group in term of gender and educational level. Data gathering was carried out with three questionnaires including a demographic-related questionnaire, disturbance questionnaire (including 35 items) and a questionnaire related to substance-dependence and its related factors. Statistical analysis was performed using SPSS 11 for Windows, t test and ANOVA.
FINDINGS: The mean score of 33 items of the identity disturbance questionnaire were greater with significant difference in the case group (P<0.05). The means differences in the two groups in all subsets were statistically significant, except for role absorption (P<0.05). The means differences in all subsets in substance-dependent and substance-independent subjects in both groups were not significant statistically. The most common substance-dependence in both groups was related to cigarette smoking and cannabis. Opium and cannabis dependence was significantly greater in patients with borderline personality disorder.
CONCLUSION: Identity disturbance is one of the major criteria for borderline personality disorder, but in different societies the role of its subsets are different. On the other hand, assessing subsets of identity disturbance has no value in assessing substance-dependence in patients with borderline personality disorder.

Introduction

Borderline personality disorder is one of the personality disorders (cluster B) in DSM- IV. Patients with borderline personality disorder often complain of chronic emptiness, sense of impatience and lack of cohesive identity.1 Physicians have been recording these patients since the late 1940s. Hoch and Polatin (1941) called these patients as "neurotic schizophrenia", and in 1954, Robert and Knight emphasized on the ego dysfunction in these patients. Grinker (1968) concluded that some of these patients show negative mood signs and have problems in consistency maintenance and interpersonal relationship; however, others were characterized by identity loss and needed to borrow identity from others.2

Identity disturbance and continuous and obvious inconsistency in self- image are major criteria for borderline personality disorder.3 According to Kernberg, identity diffusion in patients with borderline personality results from inability and failure to integrate positive and negative representations of one's self.4, 5

Adler and Buie described patients with borderline personality disorder as individuals suffering from a sense of incoherence and disjointed thinking.6, 7 Fonagy et al emphasized that patients with borderline personality disorder fail to internalize others and their own experiences.8 In addition, Westen and Cohen described these patients with lack of consistently invested goals, values, ideals, and relationships.9 Erikson used "identity crisis" for these patients and concluded that identity problems are seen across the lifespan in lower levels.10

Four factors were assessed in identity disturbance. Each factor assesses one aspect of identity disturbance.11 Role absorption is the first factor, in which patients appear to over identify with a specific group and accept their role as the only role in their own life. Hence, their own personality will be affected. The second, painful incoherence, assesses the patients’ dissatisfaction and concern about the sense of self, since they experience a lack of cohesive identity. The third, inconsistency happens when the patient's beliefs and actions often seem grossly contradictory and reflect the patient's inconsistency. The fourth factor is lack of commitment, dealt with the patients' problems in commitment to vocational or social tasks and goals.11,12

It seems that identity disturbance, which is one of the major signs of borderline personality disorder, can induce other signs and may result in other disorders such as substance abuse. Another character of this disorder is impulsive personality in at least two aspects which potentially hurts the patients (such as sexual relationships, substance abuse, careless driving and binge-eating).3

This study aimed to assess identity disturbance in patients with borderline personality disorder and to examine the relationship between identity disturbance and substance abuse.

Methods

A case-control approach was used to guide the project of inquiry. The sample size was estimated in each group equal to 40 based on α = 0.05 and β = 0.2. The case group consisted of 40 subjects diagnosed with borderline personality disorder; the samples were recruited from outpatient or inpatient cases referred to Shahid Beheshti hospital in Kerman from 2004 to 2005.

Patients diagnosed with the borderline personality disorder were assessed again based on DSM-IV criteria with a semi structured interview. After diagnosis confirmation, they were asked to participate in the study.

Then the diagnostic criteria were recorded and other demographic information (such as age, educational level, occupation, history of self- injury, tattooing, conflict with law, incarceration with sexual abuse, opioid abuse and its type) were assessed.

Then the subjects were assessed with the identity disturbance questionnaire. This questionnaire included 35 items; each reflecting one aspect of identity disturbance.11 In addition, four subsets of identity disturbance (role absorption, painful incoherence, inconsistency and lack of commitment) were assessed. Normal population (n=40) was selected randomly for the control group. They were matched with case group in term of gender and educational level.

The total score of each question and four subgroups were compared separately between two groups and between opioid-dependent and non opioid-dependent. Statistical analysis was performed using SPSS11 software by mean calculation and t-test and ANOVA.

Results

The mean age of the patients was 26.2 (SD=4.4) years in the case group and 30.5 years (SD=3.6) in the control group. All subjects were male. Eighty percent of the case group and 35 percent of the control group were single. All subjects in the control group were employed compared to the 77.5 percent unemployment in the case group There was no tattooing and self-injury history in the control group, but it was 95 percent in the case group. In the case group, 80 percent had a history of conflict with law, 60 percent had incarceration history and 17.5 percent had sexual abuse experience in childhood which was not reported at all in the control group.

In the case group, 75 percent opium abuse, 50 percent cannabis abuse, 95 percent cigarette smoking, 5 percent heroin abuse and 5 percent alcoholism were reported. In the control group, 30 percent opium abuse, 10 percent cannabis abuse and 87.5 percent cigarette smoking was reported and there was no history of heroin abuse and alcoholism. The most frequent substance abuse in both groups in order of frequency from high to low was cigarette smoking, opium and cannabis abuse. There was a significant difference between the two groups based on opium and cannabis dependence.

There were significant differences between the two groups in 33 items of the questionnaire (Table 1). Overall, there was significant difference between the two groups (P<0.05).

Table 1

Average scores of questions related to identity disturbance in the borderline personality disorder group and the control group

Identity Disturbance Item	Identity Disturbance Item	Borderline Personality Disorder		Control Group		P value
		Mean	SD	Mean	SD
1	Identity centers around not being like someone else	5.57	1.196	4	1.414	< 0.0001
2	Personality changes dramatically depending on whom the patient is with; personality is “chameleon- like”	5.47	0.933	3.10	0.598	< 0.0001
3	Sense of self depends on relationship to a charismatic other; tends to be in the orbit of a strong personality	5.07	0.492	2.98	1.641	< 0.0001
4	Values tend to change frequently; patient does not seem to have a constant set of core values	4.85	1.642	2.53	1.797	< 0.0001
5	Patient has had difficulty choosing and committing to an occupation	6.28	0.960	2.60	1.516	< 0.0001
6	Patient appears conflicted or unsure about own gender	1.40	0.928	1.95	2.037	0.249
7	Patient appears conflicted or unsure about whether he or she is heterosexual, homosexual, or bisexual	1.50	0.816	2.10	1.919	0.001
8	Patient feels as though he or she is a different person depending on whom he or she is with	5.22	1.187	2.45	1.339	< 0.0001
9	Patient holds grossly inconsistent or contradictory beliefs	5.48	0.816	0.45	1.339	< 0.0001
10	Patient frequently behaves in ways that seem inconsistent or contradictory	5.43	0.747	2.20	0.758	< 0.0001
11	Beliefs and actions often seem grossly contradictory (e.g., espouses conservative sexual values while behaving promiscuously)	5.30	0. 091	2.53	1.154	< 0.0001
12	Political beliefs have shifted frequently or dramatically	1.83	1.196	2.21	1.212	0.002
13	Patient tends to confuse own thoughts with those of others	4.38	1.709	2.53	1.154	< 0.0001
14	Patient lacks a sense of continuity over time or has difficulty recalling day to day what he or she has done	5.30	1.381	2.40	1.081	< 0.0001
15	Patient tends to feel like he or she does not know who the own self is	6.23	0.800	1.90	1.392	< 0.0001
16	Patient tends to feel empty inside	6.75	0.439	2.40	1.646	< 0.0001
17	In close relationships, patient fears losing own identity	4.62	0.868	2.18	1.430	< 0.0001
18	Patient fears he or she would no longer exist or would lose own identity if close relationship were to end	4.25	1.256	2.28	1.552	< 0.0001
19	Identity seems to revolve around a “cause” or shifting causes (e.g., defines self by membership in a political movement)	1.25	0.707	1.80	1.829	0.007
20	Sense of identity revolves around membership in a stigmatized group (e.g., child of an alcoholic, sexual abuse survivor)	3.00	1.695	1.67	1.403	< 0.0001
21	Patient defines self in terms of a label that provides a sense of identity	2.78	1.761	2.35	1.889	0.002
22	Patient embraces identity of a person who is “bad”	2.40	1.057	3.25	2.145	< 0.0001
23	Patient appears conflicted about racial or ethnic identity (e.g., totally disavows it or defines self primarily in terms of it)	2.42	1.752	2.40	1.878	0.710
24	Patient tends to feel like a “false self” whose social persona does not match inner experience	4.85	2.143	3.03	1.901	0.001
25	Patient has trouble committing to long- term goals or aspirations	6.37	0.667	3.13	1.652	< 0.0001
26	Views of whom patient would like to be are unstable and ever changing	3.65	1.578	2.95	2.062	0.005
27	Views of self change rapidly or unpredictably	4.25	1.736	2.53	1.585	< 0.0001
28	Feelings about self change rapidly or unpredictably	4.25	1.836	2.68	1.439	< 0.0001
29	Patient has trouble telling life story; narrative accounts have large gaps or inconsistencies	3.54	1.797	1.83	1.466	< 0.0001
30	Patient has had dramatic religious experiences felt to have changed his or her life (e.g., “born again” experiences)	1.00	0.000	3.08	2.068	< 0.0001
31	Patient has had “epiphany” experiences (e.g., sudden, dramatic revelations about self) felt to have changed his or her life	1.10	0.304	2.45	1.663	< 0.0001
32	Patient identifies self primarily with a group that seems unusual given sex, race, or ethnicity	1.50	1.132	1.80	1.556	0.006
33	Patient sometimes feels unreal	5.40	1.194	2.25	1.891	< 0.0001
34	Patient has memories only available under certain states	3.93	1.118	3.44	1.949	< 0.0001
35	Patient “displays” identity in ways that appear unusual or deviant (e.g., multiple tattoos, piercings, highly peculiar hair style or coloring)	2.30	1.698	1.92	1.628	< 0.0001

Table 2 presents the difference between the mean scores of four identity disturbance subsets in the two groups. The mean scores of subgroups and substance-dependence had no significant difference in both groups (Table 3 and 4).

Table 2

Average scores of identity disturbance subgroups in the borderline personality disorder group and the normal control group

DX Identity Disturbance Subgroups	BPD		MDD		P value	F
	Mean	SD	Mean	SD
Role absorption	1.765	0.513	2.125	1.42	0.136	2.2
Painful Incoherence	5.175	0.554	2.610	0.921	< 0.05	195.2
Inconsistency	5.206	0.599	2.387	1.075	< 0.05	227.3
Lack of commitment	5.105	0.592	2.745	1.22	< 0.05	119.8

Table 3

Average scores of identity disturbance subgroups in terms of drug dependency in the borderline personality disorder group

Drug Dependency Subgroups	Positive		Negative		Total		P value
	Mean	SD	Mean	SD	Mean	SD
Role absorption	1.7	0.53	1.7	0.49	1.7	0.51	0.774
Painful Incoherence	5.1	0.58	5.0	0.64	5.1	0.6	0.917
Inconsistency	5.1	0.56	5.2	0.55	5.1	0.55	0.728
Lack of commitment	5.1	0.57	4.9	0.63	5.1	0.59	0.321

Table 4

Average scores of identity disturbance subgroups in terms of drug dependency in the control group

Drug Dependency Subgroups	Positive		Negative		Total		P value
	Mean	SD	Mean	SD	Mean	SD
Role absorption	1.3	0.23	1.2	0.21	1.2	0.22	0.626
Painful incoherence	3.6	0.79	3.7	0.80	3.6	0.79	0.842
Inconsistency	3.1	0.39	3.3	0.73	3.2	0.66	0.441
Lack of commitment	3.1	1.2	2.7	1.0	2.8	1.1	0.381

Identity disturbance in this questionnaire had four subgroups; role absorption, painful incoherence, inconsistency and lack of commitment. In patients with borderline personality disorder, the highest mean was related to inconsistency, which in order of frequency from high to low was followed by painful incoherence, lack of commitment and role absorption. In the control group, the highest means were related to lack of commitment, painful incoherence, role absorption and inconsistency in order of high to low. The differences among the means in the two groups in all subsets were statistically significant except role absorption (P<0.05).

Discussion

It demonstrates that identity disturbance is one of the most consisting elements of borderline personality disorders.1, 5 Our findings showed that most factors indicating identity disturbance are significantly higher in patients with borderline personality disorder than healthy people. There was no significant difference between the two groups in term of role absorption which indicates that although diagnostic criteria based on DSM-IV in patients with borderline personality disorder were higher than the control group, these diagnostic criteria do exist in lower scale in healthy people. Previous studies showed that some of these criteria were seen in healthy people.1 Therefore, identity disturbance has a spectrum that finally results in borderline personality disorder which in lower levels can predispose psychiatric disorders or interpersonal problems.

The most common disturbance factor in patients with borderline personality disorder was inconsistency. This is different compared to Wilkinson and Western's findings. In their study, painful incoherence was the most common factor.5 In addition, in the current study, role absorption was the weakest predictor of borderline personality disorder, and there was even no significant difference between the mean scores in case and control groups. However, in Wilkinson and Western's study, lack of commitment was the weakest predictor.

It seems that although identity disturbance is a main known factor in the development of borderline personality disorder, it is a complex variable that consists of several measurable elements. It is possible to assess this variable from different aspects. Some factors may be various in different cultures because of special cultural differences.

Findings indicate that substance-dependence in the four identity disturbance subgroups had no significant difference in both groups. It shows that four subgroups of identity disturbance have no role in substance-dependence, but the borderline personality disorder itself plays a role in increasing substance-dependence. Therefore, assessing the subgroups of identity disturbance has no role in substance- dependence.

This study had two main potential limitations. Our subjects were exclusively male because there were a low number of women with borderline personality disorder in the study setting. Therefore, we could not recruit women with borderline personality disorder in the study. The second limitation was that we did not assess co-psychiatric disorders, especially in axis-I in our subjects.