Tehran University of Medical Sciences Journal of Sleep Sciences 2476-2938 4 1-2 2019 12 15 17 23 Mohammad Fadaei Department of Family Counseling, School of Education and Psychology, Ferdowsi University of Mashhad, Mashhad, Iran Amir Bavafa Department of Clinical Psychology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran Mahsa Bameshghi Department of Clinical Psychology, School of Education and Psychology, Ferdowsi University of Mashhad, Mashhad, Iran Ahmad Zarghani Department of Clinical Psychology, School of Education and Psychology, Ferdowsi University of Mashhad, Mashhad, Iran Behnaz Shid Anbarani Department of Clinical Psychology, School of Education and Psychology, Ferdowsi University of Mashhad, Mashhad, Iran Fateme Shekarian Department of Clinical Psychology, School of Basic Sciences, Neyshabur Branch, Islamic Azad University, Neyshabur, Iran Nasrin Jaberghaderi Department of Clinical Psychology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran 2019 04 26 2019 06 06 Background and Objective: Sleep and sleep-related indices can be altered in substance users especially methamphet-amine and opioid users. Studies have shown that sleep in substance users does not change uniformly. The aim of this study was to compare sleep and related indices in patients with opium and methamphetamine addiction. Materials and Methods: In this descriptive study, 143 opium and methamphetamine addicts who referred to four ad-diction treatment clinics in Kermanshah, Iran, in 2018-2019, were evaluated by four sleep questionnaires including Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and Berlin Questionnaire (BQ). Results: There was a significant difference between the two groups in the number of female participants, age of partici-pants, education level, and years of substance use (P < 0.05). Patients with opium addiction, compared to methamphet-amine users, had a poorer sleep quality, symptoms of insomnia, and sleepiness in everyday situations. Conclusion: The type of substance can affect the type of sleep problems experienced by individuals. Interventions in the fu-ture should be tailored to personalized problems of sleep, depending on the type of substance (opium or methamphetamine). https://jss.tums.ac.ir/index.php/jss/article/view/130