Adult attention-deficit hyperactivity disorders and its correlates in patients with opioid dependence: An exploratory study.

BACKGROUND: Adult attention-deficit hyperactivity disorder (ADHD) often remains undiagnosed and undertreated among patients with substance use disorders (SUDs). Research is lacking with regard to adult ADHD in individuals with SUD. The current work was intended to study the prevalence of adult ADHD among individuals with opioid dependence and its correlates, and to assess the attitude of the individuals with adult ADHD toward its treatment.
METHODS: This cross-sectional survey was conducted in 132 consecutive inpatients with opioid-dependence syndrome. Patients were assessed using the Mini International Neuropsychiatric Interview. 5.0, adult ADHD Self-Report Screening Scale, and Maudsley Addiction Profile. Those who screened positive for adult ADHD (ADHD+) were compared with those screened negative (ADHD-) on a number of sociodemographic, substance use, and clinical variable. Furthermore, attitude toward the treatment for ADHD was assessed among the ADHD+ individuals.
RESULTS: About a fifth (n=24, 18.2%) of the patients with opioid dependence screened positive for adult ADHD. One-third of the participants (n=8, 33.3%) were willing for the treatment of any kind, and only a half (n=3) was willing to pay. Earlier age of onset of opioid use (relative risk: 0.01; 95% confidence interval: 0.003, 0.85; P = 0.036) had higher likelihood to ADHD+ status.
CONCLUSION: Despite a high rate of ADHD screen positivity among individuals with opioid dependence, a majority were not willing to receive the treatment. Sensitization of: (1) addiction psychiatrist to routinely screen for ADHD, especially in the presence of certain correlates and (2) patients-caregivers about the potential benefit of treatment in effectively addressing the symptoms of ADHD effectively in this population. Copyright:

INTRODUCTION

The presence of the symptoms of attention-deficit hyperactivity disorder (ADHD) in adulthood is associated with the persistence of impairment and greater frequency of negative life events.[12] ADHD has been associated with greater rates of occurrence of substance use disorders (SUDs) in adulthood.[3] Furthermore, individuals with SUDs seem to have higher rates of ADHD than the general population. A meta-analysis reports the prevalence of ADHD in persons with SUDs to be 23.1%.[4] Opioid use disorder has a chronic relapsing course and affects more than 15 million individuals globally. The disorder is associated with considerable social, economic, and health-care costs.[5] Studies have found that patients with opioid dependence have high rates of adult ADHD.[6] A multicentric study from Europe has reported the prevalence of adult ADHD among heroin-dependent individuals to be 19.4%, and these individuals have been found to have more problematic form of drug dependence with poor resources of recovery process, unemployment, high rate of nicotine dependence, and psychiatric comorbidity.[7] Literature has suggested a higher rate of psychiatric comorbidity in opioid-dependent patients with ADHD.[6789] Further, patients with opioid dependence having ADHD are more likely to have impulsivity,[710] and more likely to have a poorer quality of life.[89] Thus, there seem to be many clinical correlates that point toward the presence of ADHD in individuals with opioid dependence who have.

ADHD still remains under-detected and under-treated in patients with SUDs. Treatment of patients with ADHD with comorbid SUD is considered somewhat challenging, particularly due to the concerns about the diversion of methylphenidate, a stimulant.[11] The limited published evidence on this topic also makes the recommendations difficult to be formulated. However, there is some evidence to suggest that ADHD symptoms in patients with opioid dependence can be treated with medications.[12] Medications for the treatment of ADHD seem to have been prescribed to <3% of the patients on the treatment for opioid dependence, which suggests a considerable treatment gap. Patient's willingness to accept treatment or medications might be one of the factors that could have led to such low rates of treatment provision for ADHD in this population.

To our knowledge, there are limited studies worldwide, and none from India, that have looked specifically at the rates of adult ADHD in opioid-dependent population and its clinical correlates. Understanding the extent of the occurrence of ADHD and its clinical characteristics in this population would be helpful in screening and planning intervention/services for them and thus would improve the quality of life and outcome of the patients. This study was planned to assess the rates of occurrence of ADHD in patients with opioid dependence and to discern the clinical characteristics which differentiate those having and those not having comorbid ADHD. Further, the study attempts to enquire whether treatment options are considered acceptable by the patients who screen positive for ADHD.

METHODS

Design

The present study is cross-sectional and observational in nature.

Setting

The study was conducted at a public-funded tertiary care drug-dependence treatment center of North India. The institute provides outpatient, day care, and inpatient services to the individual with SUDs. Most common substances for which treatment is usually sought in the study setting include: Heroin and other opioids (natural or pharmaceutical), alcohol, cannabis, nicotine, volatile substances, and stimulants. The cost of care is largely borne by the center. The treatment provided for the opioid dependence includes detoxification followed by agonist (buprenorphine) or antagonist (naltrexone) maintenance, depending upon the patient's clinical profile and preference. Although most patients are treated on an outpatient basis, a subset of the population requires inpatient treatment. The usual duration for which admission is required varies from 10 to 21 days. Patients are usually admitted to the center without any family members. However, family members are routinely contacted from the clinical or management perspectives, and if clinically indicated, they are allowed to stay with the patients. The focus of treatment apart from pharmacotherapy includes nonpharmacological interventions such as motivation enhancement therapy, relapse prevention sessions, family interventions, and sociooccupational rehabilitation depending upon the needs of the patients and that of their caregivers.

Participants and procedure of the study

A convenient sampling method was used for participant recruitment for the present study. All the consecutive patients of opioid dependence admitted in the center were approached for their participation in the study. The inclusion criteria for the participants were age more than or equal to 18 years, of either gender, fulfilling diagnostic criteria of opioid dependence syndrome as per the International Classification of Diseases-tenth revision (ICD-10), and willing to give consent for participation in the study. The exclusion criteria were: suffering from acute psychiatric problems (such as current mood or psychotic episode or prominent anxiety etc.) or unstable medical condition (such as uncontrolled hypertension, diabetes, or delirium) (based on records and clinical assessment), and having features of intoxication or significant withdrawals (Clinical Opiate Withdrawal Scale scores more than 12) precluding their assessments.

The data were collected from October 2018 to April 2019 by the trained psychiatrist (SG and GB). A semistructured questionnaire was used to collect the information about participant's sociodemographics such as age, gender, educational status, occupation, employment status, marital status, current living arrangement, and residential status. Basic substance use and clinical details such as the duration of opioid use, type of opioid use, injecting drug use, presence of other substance dependence, and comorbid medical illness was also recorded.

Mini International Neuropsychiatric Interview. 5.0 was used to assess for the presence of comorbid psychiatric illnesses. Maudsley Addiction Profile (MAP) was used to assess the problems associated with substance use. Further, the Adult ADHD Self-Report Scale (ASRS) was used to assess for the symptoms of adult ADHD. Moreover, those who were screened positive for adult ADHD were further asked about their perceived need for treatment, preferred forms of treatment (pharmacological or psychotherapeutic), and their willingness to bear the cost of the treatment.

The study had approval of Institutional Ethics committee.

Measures

Mini International Neuropsychiatric Interview. 5.0

This is a structured instrument to ascertain several psychiatric disorders as per the Diagnostic and Statistical Manual of Mental Disorder, fourth revision (DSM IV), and ICD 10. It is a short-structured diagnostic interview, which has been jointly developed by psychiatrists and clinicians. It was designed to meet the need for a short but accurate structured psychiatric interview. It requires about 20 min. to administer by a clinician. It has got excellent psychometric properties.[13]

Maudsley Addiction Profile

This is a brief instrument to assess the problems pertaining to alcohol and drugs use in the past 30 days in the following four domains: Substance use pattern (frequency and amount of substance use, presence of drug overdose, injection drug use, and high-risk sexual behavior), health risk behavior, physical and psychological health, and personal/social functioning. It takes about 15 min. to administer. The instrument gives a numerical score to represent the number of days/times a particular adverse event that has occurred. The instrument has acceptable psychometric properties.[14]

Adult attention deficit hyperactivity disorder Self-Report Scale

This is a self-reported instrument to assess for the presence of adult ADHD. It has been developed in conjunction with the World Health Organization. This brief questionnaire comprises 18 DSM-IV, Text Revision criteria. The questionnaire consists of two parts: Part-A comprises six questions, four out of which if fall in dark shaded areas are highly consistent with adult ADHD and serve best as a screener, and Part-B, comprises of 12 questions, and serve as additional cues into patient's symptomatology without having any screening utility. The questionnaire assesses for ADHD features in the past 6 months. The questionnaire has good specificity, fair sensitivity, and good diagnostic accuracy. In the present study, ASRS has been used as a screening tool for adult ADHD. Attempts were made to enquire about the presence of ADHD features when the patients were not under the influence of the substance or were experiencing any withdrawal or were in the period of abstinence from the substance. Those screening positive for ADHD were planned for the detailed assessment, preferably by interviewing the family members as a part of comprehensive assessment and management, though in the current study, only those screened positive were taken into account.[15]

Analysis

The sociodemographic and substance use details of the participants were calculated in terms of percentages and mean (with standard deviation) or median (interquartile range), according to the characteristics of the variables. Those who screened positive for ADHD (ADHD+) and those who did not (ADHD-) were compared using the appropriate statistical analysis. Scores of MAS were log-transformed for the comparison between the two groups and regression analysis. A logistic regression test was performed to assess the correlates of the ADHD among the participants. The level of statistical significance was kept at P < 0.05 for all the tests. The data collected were analyzed using the SPSS statistical package, version 21 (IBM Corp., Armonk, NY, US).[16]

RESULTS

Sociodemographic, substance use, and clinical-profiles of the participants

Of the screened participants (n = 182), only 132 participants were found eligible for the study. The reasons of exclusion were age <18 years (n = 24), unable to co-operate for assessment (n = 24) due to comorbid acute psychiatric (n = 20; n = 7, had an acute depressive episode; n = 4, had a manic episode; and n = 9, had an acute psychotic episode) or medical conditions (n = 4), and premature discharge from the center before an assessment could be completed (n = 2).

The mean age of the participants was 27.74 (8.47) years; all of them were males. The median duration of opioid use was 6.0 (interquartile range [IQR]: 4.0, 8.75) years. The median (IQR) Clinical Opiate Withdrawal Scale (COWS) score at the time of assessment was 1.0 (0.0, 2.0). Heroin was the primary opioid of use in about three-fourth (n = 100) of the participants. About one-fifth (n = 27) of the participants were injecting drug users; out of them, about one fourth (n = 7) were also involved in needle sharing and a half (n = 13) in needle/syringe reuse. Regarding comorbid substance use, almost all (n = 127) were dependent on nicotine and slightly more than one-third (n = 46) were dependent on cannabis. Mood disorder (n = 26) was the most common psychiatric comorbidity among the participants [details in Table 1].

Table 1

Sociodemographic and clinical profiles of the participants (n=132)

Variables	n (%)/central tendency (SD/IQR)
Age (years)	27.74 (8.47)
Gender
Male	132 (100)
Marital status
Unmarried/separated/divorced	87 (65.9)
Married/widower	45 (34.1)
Education
Up to primary level	39 (29.5)
More than primary level	93 (71.5)
Occupational status
Unemployed/never employed	62 (47.0)
Currently employed	70 (53.0)
Residence
Rural	77 (57.3)
Urban	55 (42.7)
Family type
Alone	2 (1.5)
Nuclear	89 (67.4)
Extended nuclear/joint	41 (31.1)
Per capita monthly family income (INR)	5754 (3000, 10,000)
Age of the onset of opioid use (years)	19.9 (5.8)
Duration of opioid use (years)	6.0 (4.0, 8.75)
Type of opioid use
Heroin	100 (75.8)
Natural opioid (opium etc.)	2 (1.5)
Prescription opioids	13 (9.8)
Mixed	17 (12.9)
Presence of IDU	27 (20.45)
History of sharing needles/paraphernalia	7 (21.9)
Presence of reuse of the needle/syringe	13 (40.7)
Comorbid substance use
Alcohol dependence	9 (6.8)
Cannabis dependence	46 (34.8)
Sedative/hypnotic dependence	11 (8.3)
Nicotine dependence	127 (96.2)
Others (like volatile solvents)	3 (2.3)
Comorbid psychiatric illness
Mood disorder	26 (19.7)
Anxiety spectrum disorder	6 (4.6)
Schizophrenia and related disorders	1 (0.8)
Personality disorder	11 (8.3)

SD/IQR – Standard deviation/interquartile range; INR – Indian national rupees; IDU – Injecting drug use

Findings on Adult Attention-Deficit Hyperactivity Disorder Self-Report Scale

As high as 18.2% (n = 24) of the participants screened positive for adult ADHD (ADHD+) [details of their responses on ASRS shown in Table 2].

Table 2

Criteria wise responses of the participants in adult attention-deficit hyperactivity disorder self-report scale and attitude toward treatment

	Never	Rarely	Sometime	Often	Very often
1. How often do you have trouble wrapping up the final details of a project, once the challenging parts have been done? (A)	39 (29.5)	49 (37.1)	35 (26.5)	8 (6.1)	1 (0.8)
2. How often do you have difficulty getting things in order when you have to do a task that requires organization? (A)	46 (34.8)	44 (33.3)	30 (22.7)	12 (9.1)	0. (0.0)
3. How often do you have problems remembering appointments or obligations? (A)	48 (36.4)	38 (28.8)	35 (26.5)	10 (7.6)	0 (0.8)
4. When you have a task that requires a lot of thought, how often do you avoid or delay getting started? (A)	48 (36.4)	41 (31.1)	22 (16.7)	15 (11.4)	6 (4.5)
5. How often do you fidget or squirm with your hands or feet when you have to sit down for a long time? (H)	70 (53.0)	23 (17.4)	21 (15.9)	15 (11.4)	0 (2.3)
6. How often do you feel overly active and compelled to do things, like you were driven by a motor?(H)	66 (50.0)	31 (23.5)	15 (11.4)	18 (13.6)	2 (1.5)
Screen positive for adult ADHD#	24 (18.2)
Attitude toward treatment for ADHD
Willingness for treatment
Yes	8 (33.3)
No	2 (8.3)
Don’t know	11 (45.8)
Did not respond	3 (12.6)
Willingness to receive pharmacotherapy (n=8)
Yes	6 (75)
No	0 (0.0)
Don’t know	2 (25)
Willing to pay for the pharmacotherapy (n=6)
Yes	3 (50.0)
No	3 (50.0)
Don’t know	0 (0.0)
Willingness to receive psychotherapy (n=8)
Yes	6 (75)
No	1 (12.5)
Don’t know	1 (12.5)

#As measured by Adult ADHD Self-Report Scale, †Data available for 21 participants only. A – Inattention; H – Hyperactivity; ADHD – Attention-deficit hyperactivity disorders

Attitude toward treatment among participants screened positive for adult attention-deficit hyperactivity disorder

Regarding attitude toward treatment among adult ADHD screened positive patients, only one third (n = 8) were “willing” to receive treatment while roughly half (n = 11, 45.8%) of them were “not sure” about receiving treatment. Among those who expressed their willingness to receive treatment, pharmacological and nonpharmacological interventions were equally preferred to them (n = 6, 75%). Moreover, a large proportion (n = 6, 75%) of those who were willing to receive treatment were also ready to pay for it.

Comparison of adult attention-deficit hyperactivity disorder status (ADHD+ vs. ADHD−) based on the substance use- and addiction severity profiles

The age of onset of opioid use was significantly lower among the participants who screened positive for adult ADHD (ADHD+) in comparison to their ADHD− counterparts. Similarly, there was significantly higher physical health, anxiety, depressive scores, a higher proportion of days involved in a conflict with the friends, not being able to perform social responsibilities among ADHD+ individuals than those individuals having ADHD− status [Table 3]. Further, significantly higher proportions of the ADHD+ individuals (versus ADHD−) were involved in risky behavior such as opioid overdose and needle/syringe sharing [Table 4].

Table 3

Mean difference of variables with regard to attention-deficit hyperactivity disorders status of the clients

Variables	Mean±SD		Mann-Whitney U-test§, P
	Screened positive for ADHD (n=24)	Screened negative for ADHD (n=108)
Age of onset of heroin use	17.25 (5.36)	20.42 (5.82)	U=1129.0, P=0.048*
Duration of opioid use	7.69 (5.03)	7.75 (6.51)	U=1385.50, P=0.68
Proportion of days consumed heroin in the last 1 month†	86.66 (23.33)	81.66 (29.07)	U=1050.00, P=1.00
Proportion of days consumed alcohol in the last 1 month†	7.77 (5.01)	20.00 (26.47)	U=161.00, P=0.40
COWS†† score	1.88 (2.42)	1.35 (1.99)	U=1209.50, P=0.14
Number of times indulged in unprotected sex	6.00 (6.21)	6.08 (7.21)	U=120.00, P=0.62
Physical health score†	16.28 (7.14)	13.58 (6.61)	U=995.50, P=0.010*
Psychological health score†
Anxiety score	6.94 (6.29)	4.30 (3.77)	U=825.00, P<0.001*
Depression score	8.50 (3.96)	5.64 (3.77)	U=820.00, P<0.001*
Proportion of days spent outside home†	20.62 (26.26)	9.08 (18.36)	U=1122.00, P=0.054
Proportion of days involved in paid job†	61.48 (35.39)	66.76 (35.25)	U=200.00, P=0.86
Proportion of days involved in unauthorized absenteeism	39.47 (23.06)	24.29 (29.73)	U=175.50, P=0.14
Proportion of days involved in voluntary job†	50.00#	43.59 (34.53)	U=51.50, P=0.40
Proportion of days performed responsibility towards dependents†	41.88 (39.20)	64.58 (40.30)	U=703.50, P=0.68
Proportion of days remained unemployed†	87.19 (24.02)	88.8 (22.07)	U=341.50, P=0.83
Proportion of days involved in conflict with the partners†	25.48 (34.09)	21.47 (34.99)	U=262.00, P=0.12
Proportion of days involved in conflict with relatives†	36.02 (29.36)	22.42 (31.40)	U=504.50, P=0.082
Proportion of days involved in conflict with friends†	9.81 (16.90)	7.37 (18.51)	U=1046.50, P=0.042*

*p value <0.05.†As assessed in Maudsley addiction profile; §Variables were not normally distributed, as analysed by Shapiro-Wilk test; ††Clinical opioid withdrawal scale; #Standard deviation could not be calculated. COWS – Clinical Opiate Withdrawal Scale; SD – Standard deviation; ADHD – Attention deficit hyperactivity disorders

Table 4

Comparison between attention-deficit hyperactivity disorders (positive vs. negative) status of the clients with different variables as analyzed by the Chi-square test

Variables	Screened positive for ADHD (n=24)	Screened negative for ADHD (n=24)	Pearson χ2, P
Currently staying with the partner	7 (25.0)	38 (36.5)	1.30, 0.24
Completed at least middle schooling	20 (71.4)	73 (70.2)	0.16, 0.89
Currently employed	12 (42.9)	58 (55.8)	1.47, 0.22
Comorbid substance use along with opioids	11 (39.3)	51 (49.0)	0.84, 0.35
Comorbid psychiatric illness	10 (35.7)	23 (22.1)	2.17, 0.15
Presence of IDU	5 (17.9)	22 (21.2)	0.14, 0.69
History of opioid overdose†	5 (20.8)	7 (6.5)	4.89, 0.027*
History of high-risk sexual behavior	7 (70.0)	29 (76.3)	0.16, 0.68
History of needle/syringe sharing†	7 (25.0)	0 (0.0)	1.88, 0.007*
History of reuse of needle/syringe	5 (17.9)	14 (13.5)	0.34, 0.56
Looked after the dependents	11 (45.8)	70.4 (76.0)	5.263, 0.022*
Involvement in illegal activities	9 (37.5)	37 (28.7)	0.71, 0.39

*p value <0.05. †Fisher's exact test was applied. IDU – Injecting drug use; ADHD – Attention-deficit hyperactivity disorders

Correlates of adult attention-deficit hyperactivity disorder

A multivariate logistic regression analysis (only variables associated with ADHD+ on univariate logistic regression analysis at P < 0.1 were entered into multivariable logistic regression analysis) showed that the “earlier age of initiation of opioid use” had higher likelihood for the ADHD+ status (relative risk: 0.01; 95% confidence interval: 0.003, 0.85; P = 0.036). Although on univariate logistic regression analysis variables such as “presence of opioid overdose, “higher physical,” “higher anxiety,” and “higher depression scores” on MAP; “not looking after one's dependents” were found to have a higher likelihood for adult ADHD, the same turned out to be nonsignificant on the multivariate regression analysis. The details about the findings on regression analysis are shown in Table 5.

Table 5

Correlates of attention-deficit hyperactivity disorders in respect to various sociodemographic, substance use- and adverse consequences related variables† of the clients by logistic regression analysis

Variables	Logistic regression
	RR	95% CI	P
Age of onset of heroin use
UV	0.01	0.001, 0.87	0.012*
MV	0.005	0.003, 0.85	0.043*
History of overdose (reference number overdose)
UV	3.79	1.090, 13.22	0.036*
MV	2.33	0.56, 9.77	0.24
Presence of needle/syringe sharing (reference number needle/syringe sharing)
UV	0.87	0.26, 2.88	0.83
MV	0.34	0.02, 5.05	0.43
Higher physical health score in MAP
UV	6.10	0.75, 49.47	0.09
MV	0.50	0.04, 6.07	0.97
Higher anxiety score in MAP
UV	6.18	1.35, 21.38	0.019*
MV	4.60	0.68, 31.18	0.116
Higher depression score in MAP
UV	31.11	2.79, 346.74	0.005*
MV	10.38	0.52, 206.08	0.12
Looked after the dependents (reference not looking after the dependents)
UV	2.80	1.138, 6.924	0.025*
MV	2.83	0.98, 8.15	0.053

*p value <0.05.†Only those variables were subjected to univariate logistic regression analysis which showed association with ADHD in the Chi-square test or in Mann-Whitney U-test. UV – Univariate; MV – Multivariate; RR – Relative risk, CI – Confidence interval; MAP – Maudsley addiction profile; ADHD – Attention-deficit hyperactivity disorders

DISCUSSION

Our study was intended to assess the rate of adult ADHD, based on a screening tool, among patients with opioid dependence, and its sociodemographic, clinical, and substance use related correlates. We also tried to explore the attitude of the participants about their willingness to receive treatment, their preference for the available treatment, and their willingness to bear the cost for the same.

We found the prevalence of adult ADHD among individuals with opioid-dependence syndrome (ODS), to be 18.2%, which is consistent with the previous literature.[4791718] These findings underscore the need to routinely assess for ADHD in adults with problematic substance use. However, our findings should be considered in the light that we used ASRS, which is just a screening instrument for adult ADHD. Moreover, we made a cross-sectional diagnosis which was based on the subjective reporting by the patient. Hence, future research based on a more detailed assessment (preferably involving family members), after a significant period of abstinence from the substance, and assessing longitudinal course is warranted in the current study population.

Literature has suggested that diagnosing adult ADHD in substance using population is difficult and complicated by the overlapping symptoms of substance-related craving or withdrawal.[192021] For instance, impulsivity or hyperactivity could be the manifestation of craving or withdrawal of substance. Similarly, inattention could be a manifestation of cognitive problems emanating from the adverse effect of a substance or comorbid depressive or anxiety disorders. Further, cognitive impairment caused by the current substance use or chronic substance use in the past may lead to recall bias. To address some of these issues: (1) we only assessed those individuals whose withdrawal symptoms have subsided or were minimal at the time of assessment and (2) those having acute mood or psychotic illness were excluded from the study.

We also noticed that only one-third of the individuals who screened positive for adult ADHD were willing for the treatment while a majority were unsure if they would like to receive treatment, thus reflecting their unawareness about the need for the treatment of adult ADHD. Studies have shown that adult ADHD is an underdiagnosed condition in general; and far more underrecognized in the substance using population.[22] Further, adult ADHD is often undertreated in individuals with SUDs;[2324] associated with resistance to treatment for cooccurring SUDs, which in turn leads to the poor prognosis for the comorbid SUDs.[3923]

Among individuals who were willing for the treatment for ADHD, both pharmacological and nonpharmacological interventions were equally acceptable.[24] However, only half of them (n = 3) were willing to pay for it. This shows that receiving treatment for ADHD was of less priority for the participants as compared to the treatment for their substance use problems. This underscores the need for psychoeducation of both the patients and their family members, about the need for treatment for comorbid ADHD, and how it can affect the course and prognosis of underlying SUDs. Although paradoxically, it may appear premature to explore the attitude of the patients toward the treatment based on the findings on the screening instrument and without confirming the diagnosis, the study findings are important in the sense that without assessing the attitude of the patients toward treatment (including the willingness to receive treatment and pay for it) the whole exercise of screening for adult ADHD or for that any other psychiatric or medical conditions becomes futile. These considerations might be of pragmatic importance for the actual delivery of treatment options for patients with opioid dependence with a confirmed diagnosis of adult ADHD.

We found an earlier age of onset of opioid use among the study population who had comorbid adult ADHD, a finding which is consistent with the previous studies.[2526] Studies have shown that ADHD is associated with the traits of higher reward-seeking and impulsivity that poses one at an increased risk of early experimentation with the substances and also getting dependent earlier on the licit and illicit substance.[272829] Substance use also has been shown as a form of self-medication among individuals having features of ADHD.[233031]

We also found that those individuals who were not looking after the dependents, i.e., not performing familial responsibilities were more likely to have adult ADHD. This finding is consistent with previous studies that has highlighted poor quality of life and greater familial/social problems among individuals with adult ADHD with comorbid SUDs.[289] This finding emphasizes the need for early identification for ADHD and prompt intervention to prevent such complications.

On univariate regression analysis, we found that individuals screened positive for adult ADHD were more likely to have opioid overdose. This could be attributed to the feature of impulsivity seen in the patients of ADHD.[272829] However, this finding was not found to be significant on multivariate regression analysis. Similarly, higher scores on physical- and psychological-health (anxiety and depression) were found to be related to the adult ADHD on univariate, but not in multivariate, regression analysis. Literature have suggested a high prevalence of anxiety and depressive symptoms among patients of heroin dependence with comorbid ADHD, which is caused by their shared etiology or opioid withdrawal symptoms or life stressors secondary to substance use.[83233] The negative findings in the multivariate regression analysis in the present study might be due to a relative modest sample size, which might have been underpowered to elicit these association. Hence, future studies with larger sample size are warranted.

Interestingly, we did not find a higher rate of psychiatric comorbidity, including personality disorder,[34] among individuals with ODS and comorbid adult ADHD, which is contrary to the available literature.[435] Again, this might be attributable to a modest sample size of the current study. Hence, these findings should be interpreted with some caution, and more studies with a higher sample size and the different clinical settings are warranted.

Overall, our findings have some important clinical and public health-related implications. Routinely screening for cooccurring ADHD among substance using population and promptly intervening can probably reduce the complications related to comorbid ADHD, improve treatment adherence, resulting in better treatment outcome for the primary SUD. These findings also highlight the need to sensitize and train the health professionals working in the field of addiction psychiatry. Further, it emphasizes that patients with adult ADHD and their family members should be adequately counselled about the long-term issues and purported benefits of interventions.

Limitations

The findings of our studies should be considered in light of certain limitations. The screening questions for assessing adult ADHD might not have been able to discern the symptoms of ADHD from the symptoms attributable to long-term SUD or concurrent mental health problems. A major limitation also pertains to screening assessment not being coupled with detailed clinical diagnostic evaluation for ADHD. Further, the findings on the cross-sectional assessment of patients in acute care setting might differ from those stabilized on long-term medications. The included patients formed a heterogeneous group with many individuals having comorbid psychiatric illness and other SUDs; although the sample represents patients that are likely to be typically encountered in an inpatient setting, the vulnerability of having ADHD might be different across groups. Further, because of a modest sample size, the study might have been underpowered to run the tests of association involving multiple independent variables. In addition, the study did not look into other closely related constructs such as impulsivity. The possibility of response biases cannot be totally ruled out. Furthermore, since the study involves hospitalized patients and all the participants being males, the findings cannot be generalized to outpatient or primary care clinics and in females, respectively.

CONCLUSION

Our study found a considerable prevalence of possible adult ADHD in individuals with opioid dependence, a majority of whom were not sure of receiving treatment for the same. Among those who were willing for the treatment, there was an equal preference for both the nonpharmacological intervention and pharmacological intervention, though payment issues might need close consideration. Earlier age of onset of opioid use and not looking after dependents, not performing familial responsibility, were important correlates of adult ADHD.

Further studies are required with higher sample size, in different clinical settings, and those assessing the impact of the intervention for ADHD in decreasing the adverse outcomes among the individuals with comorbid opioid dependence. Sensitization of health care providers is required to screen for adult ADHD among the substance using population through a detailed assessment. Further, patients and their caregivers should be sensitized about the interplay of SUD and co-occurring ADHD and the potential benefit of treatment.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.