en Psychiatry Psychiatry Original Research Original Research <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-style:italic"><b><span style="font-size:9.0pt"><span style="font-style:normal">Background: </span></span></b><span style="font-size:9.0pt"><span style="font-style:normal">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. </span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal">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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; <b>Methods:</b> The participants of this cross-sectional study were 320 patients with substance use disorder based on the DSM&ndash;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&ndash;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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; <b>Results:</b> 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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span new="" roman="" style="font-family:" times=""><span style="font-style:italic"><b><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; Conclusion: </span></span></b><span style="font-size:9.0pt"><span style="font-style:normal">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.</span></span></span></span></span></span></span></span><br> &nbsp; Substance Use Disorder, Comorbidity, Mood Disorders 17 22 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-7706-1&slc_lang=en&sid=1 Mahsa Oladikalarijani dr.m.oladi.k@gmail.com 200319475328460075957 200319475328460075957 Yes Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Amir Shabani shabani.a@iums.ac.ir 200319475328460075958 200319475328460075958 No Mental Health Research Centre, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Shiva Soraya Dr.shivasoraya@gmail.com 200319475328460075959 200319475328460075959 No Research Center of Addiction and Risky Behavior, Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Hamidreza Ahmadkhaniha dr_ahmadkhaniha@yahoo.com 200319475328460075960 200319475328460075960 No Research Center of Addiction and Risky Behavior, Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran