Validation of Persian version of PHQ-9 for diagnosis of major depressive episode in psychiatric wards in IRAN

Major depressive disorder is one of the most serious and disabling psychiatric disorders. It can be followed by medical problems, impaired individual functioning, reduced quality of life and mortality (1-3). The prevalence varies among different countries. This discrepancy depends on genetics, environmental parameters, racial factors, cultural differences in perceiving diagnostic parameters, psychometric characteristics of diagnostic tools and sampling protocol (3). Major depressive episode may happen during major depressive disorder (unipolar depression) and also in bipolar disorder type I and II patients.