Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 29 4 2026 04 01 Persian Youth Cohort (PYC) for Study of Mental Health in Iran: Study Protocol and Participant Profile 213 225 10.34172/aim.35612 EN Afarin Rahimi-Movaghar https://orcid.org/0000-0002-5761-1668 Seyed Abbas Motevalian Ahmad Hajebi Vandad Sharifi https://orcid.org/0000-0002-1031-3049 Ramin Mojtabai Habibolah Khazaie Farid Najafi Mojtaba Farjam Azizallah Dehghan Hamid Hakimi Mehran Zarghami Maryam Sefidgarnia Kamaledin Alaedini Bahareh Fakhraei Ali Zakiei Hossein Poustchi Reza Malekzadeh Maryam Ardeshir Jaleh Gholami Masoumeh Amin-Esmaeili Journal Article 10.34172/aim.35612 2025 12 23 2026 03 27 Introduction: We describe a cohort study of the Iranian youth with the primary aim of providing information on incidence, correlates, and the course of eight common mental disorders. Methods: The Persian Youth Cohort (PYC) is a population-based longitudinal study. We recruited 11,592 Iranians aged 15-34 years, residing in four districts in the west (Ravansar), south (Fasa), southeast (Rafsanjan), and north (Sari) of the country between 2015 to 2020. In addition to psychiatric assessment for major psychiatric disorders using modified composite international diagnostic interview-version 2.1 (CIDI-v2.1), data on psychosocial conditions, potential risk/protective factors, mental health service use, and medical history are also collected. The study is planned to continue for at least eight years after enrollment in each site. Results: In this study, we present the design, methodological considerations, and the number of participants interviewed in each phase. The median age of participants was 27.0 years (IQR=9.0) and more than half (58.8%) were married. Notably, 4.5% of participants reported lifetime suicide attempts, while the prevalence of any lifetime mental disorder, as evaluated in this study, was found to be 30.2%. Conclusion: This study will provide valuable data on the incidence of mental disorders and help identify risk and protective factors for mental health problems. It will also provide insight into trajectories of mental disorders and critical information about the future mental health care needs that the country’s healthcare system will be facing.