During the period of the months from September to December 2009, 141 subjects in DIC group and 120 subjects in Razy Hospital (Baghdad, Iraq) group were sampled in East Azerbayjan province, Iran. DIC centers in East Azerbayjan (Tabriz, Maragheh, and Mianeh) consisted of a government center, six private centers, and 10 mobile teams. The services provided by the DIC centers include: 1) admission and examination of the intravenous drug abuser, 2) provision of counseling services, 3) provision of free disposable syringes, 4) education of the mode of use of provided syringes and injection method, 5) counseling regarding substitution of methadone therapy for drug injections and its benefits, and 6) education of evidence of unsafe behaviors for prevention of diseases (16). DIC group consisted of intravenous drug abusers serviced by DIC centers.

We sampled all 10 DIC teams in proportion to the approximate number of addicts in region. The method of sampling was convenient and was continued for 4 months. Razy Hospital group consisted of subjects attended to receive methadone. Enrollment criteria for this group consisted of subjects who had been intravenous drug abusers at least during the last 4 months and who had not been subjected to services of DIC centers.

The data collection instruments included a checklist for demographic variables and a structured and trained interview list for drug-related variables and the General Health Questionnaire-28 (GHQ-28). The GHQ-28 was used to assess psychiatric in respondents. This questionnaire was developed by Goldberg and Hillier to screen somatic symptoms, anxiety and insomnia, social dysfunction, and severe depression. A review of studies on the validation of the GHQ-28 in different countries demonstrates its high validity and reliability as a screening tool of mental well-being in the community. This questionnaire was translated into the official language of Iran (Persian), which is comprehensible to almost every Iranian, and its validity and reliability were approved in previous independent studies (15, 17). The estimated intra-class correlation between the test–retest scores was 0.84, 0.85, 0.79, 0.88, and 0.91 for physical condition, anxiety, social dysfunction severe depression, and total score, respectively (18). For each item, four possible answers are available; 1: not all (score = 0), 2: no more than usual (score = 1), 3: rather more than usual (score = 2), and 4: much more than usual (score = 3). The score for subscales and total score were computed by summing over ranks in related items. For each item, including physical condition, anxiety, and social dysfunction subscales there were seven questions, and hence the possible range of scores for them is 0 - 21. For total score, the possible range would be 0 - 84. Likert scoring method of GHQ showed a cut-off point of 23 (scores higher than 23 indicate a mental disorder). The sensitivity, specificity, and the overall misclassification rates are of 70.5%, 92.3%, and 12.3%, respectively (15, 18).

Data collection was performed by face-to-face interviewing with the help of a psychologist and each center’s head, who was a rehabilitated ex-addict (in order to have a good communication potential with the drug abusers). The interviewers had been totally trained by a physician and an epidemiologist. Furthermore, a gift was offered to each drug abuser in order to motivate the addicted patient for cooperation.

All analyses were performed using SPSS for Windows 18.0 (SPSS Inc., Chicago, IL, USA). Data were presented as mean with a standard deviation (SD) or 95% confidence interval (CI) and frequency (percent) for quantitative and qualitative variables, respectively. The mean score of the GHQ-28 subscales and its total score was compared between DIC and Razy centers using independent samples t-tests. Univariate and multiple logistic regression analyses were performed to assess the relationship between psychiatric distress and subjective report of criminal activity with controlled type and number of abused substance, use of alcohol and demographical variables. In this approach, significant variables in the univariate analyses were candidate to enter in the multivariate analysis. Some variables were deleted due to low number of the observations in some of their categories. Odds ratios (OR’s) and their 95% CI’s were presented as the effect size of the relationships. P value < 0.050 was considered as statistically significant.