Comorbidities of Major Depressive Disorder and Bipolar Disorders in Patients with Substance Use Disorder in Iran Psychiatric Hospital: A Cross-sectional Study

Background: Mood disorders are the most common psychiatric comorbidities in substance users. Mood disorders and substance use disorders are 2 intertwined processes in which treating one aid in treating the other. Depression and substance use disorder are now regarded as major mental health issues due to their widespread incidence. The study was designed to investigate the prevalence of major depressive disorder (MDD) and bipolar I and II disorders in patients with substance use disorder.    Methods: The participants of this cross-sectional study were 320 patients with substance use disorder based on the DSM–5 (diagnostic and statistical manual of mental disorders 5th edition) criteria in Iran Psychiatric Hospital in 2020, who were assessed using the SCID-5-CV (Structured Clinical Interview for DSM–5 disorders-clinician version), and the demographic and clinical variables questionnaire considering familial and substance use history. The chi-square, Fisher, independent t test, and logistic regression were used to analyze the data.    Results: Of the patients, 32.8% (n = 105) had mood disorders. The most common mood disorder was MDD (16.9%, n = 54), followed by bipolar I (12.5%, n = 40) and bipolar II (2.8%, n = 9) disorders. Methamphetamine was the most commonly used substance (47.5%, n = 152). Also, 62.5% (n = 200) of participants consumed 2 or more substances simultaneously. The chance of having a mood disorder in married and divorced patients was 2.12 and 2.04 times more than in single patients, respectively.    Conclusion: The lifetime prevalence of bipolar I disorder in patients with substance use disorders is several times more than the general population, thus psychiatrists should pay more attention to mood comorbidities diagnosis and treatment in substance users.