Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 16 2 2021 04 05 124 130 Seyedeh Bentolhoda Mousavi Psychosis Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Peter Higgs Department of Public Health, La Trobe University, Bundoora, 3083 Australia. Negar Piri School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Ensieh Sadri Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Matina Pourghasem Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Sanaz Jafarzadeh Fakhari Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Mehdi Noroozi Psychosis Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Mojtaba Miladinia Student Research Committee, School of Nursing and Midwifery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Elaheh Ahounbar Substance Abuse and Dependence Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Asaad Sharhani Department of Epidemiology and Biostatistics, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. 2020 04 02 Objective: Although comorbidity of psychotic disorders and substance use can lead to increase in mortality, less is known about the outbreak and predictors. Psychotic patients tend to be overlooked during assessment; hence, the possibility of an undertreated or missed condition such as increasing substance use. This investigation aimed to measure the prevalence of substance use in psychotic patients and to survey the powerful predictors. Method: In a 1-year cross-sectional study, 311 psychotic patients were assessed using the Structured Interview Based on DSM-5 for diagnostic confirmation as well as questions surveying prevalence and possible predictors of substance use. Results: Prevalence of substance use among psychotic patients was 37.9%. Several variables were identified as factors associated with drug abuse among the psychotic patients. These included male gender, younger age, being currently homeless, a history of imprisonment, and having family history of drug use. The strongest predictors of substance use, however, were family history of drug use, male gender, and being currently homelessness. Conclusion: Policymakers should note the importance of substance use among psychotic patients. Developing active screening strategies and comprehensive preventive plans, especially in the high-risk population, is suggested. https://ijps.tums.ac.ir/index.php/ijps/article/view/2091 https://ijps.tums.ac.ir/index.php/ijps/article/download/2091/994