Prevalence of anxiety disorders and its co-occurrence with substance use disorder: a clinical study

Background Epidemiological studies are necessary to develop diagnostic standards for mental disorders. Therefore, this study investigated the prevalence of anxiety disorders, and its correlation with different substances used by patients diagnosed with substance use disorder referred to the Iran Psychiatric Hospital located in Tehran, Iran. Two hundred ninety-two male patients aged 18-65 (Mean(age) = 36.11, SD = 10.55) were recruited according to the available participant pool. Structured Clinical Interview for DSM-V Axis I Disorders was used to investigate their simultaneous anxiety disorders, and then the correlations with the different substances used during the past year before our study were considered. Based on clinical evaluation and structured psychiatric interviews, we investigated panic disorder, agoraphobia, social anxiety disorder, and generalized anxiety disorder. Results Results revealed that generalized anxiety disorder was the most common type of anxiety disorder among subjects of the current study. Further investigations revealed that panic disorder was significantly correlated with the abuse of cannabis (r = 0.116, p value = 0.047), tramadol (r = 0.205, p value < 0.001), and LSD (r = 0.197, p value = 0.001). Moreover, social anxiety disorder was correlated with cannabis (r = 0.124, p value = 0.035), opium (r = 0.186, p value = 0.001), methadone (r = 0.152, p value = 0.010), tramadol (r = 0.258, p value < 0.001), alcohol (r = 0.133, p value = 0.023), LSD (r = 0.123, p value = 0.036), and benzodiazepines (r = 0.168, p value = 0.004). The results indicated that none of the substances was correlated with generalized anxiety disorder as well as agoraphobia. However, agoraphobia had correlations with the intravenous injection as the main route of administration (r = 0.174, p value = 0.004). Conclusions Here this study supports the notion that co-occurrence of psychiatric disorders is relatively common and must be taken into consideration when assessing a patient and following up the treatment.