Importance: No national information is available on the epidemiology of psychiatric disorders in Iran for the last decade.
Objectives: To estimate the 12-month prevalence of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) psychiatric disorders in Iranian population, and to investigate the severity and correlates of psychiatric disorders.
Design, setting and participants: The Iranian Mental Health Survey (IranMHS) was a nationally representative face-to-face household survey with a multistage, cluster sampling design that was carried out in 2011. A total of 7886 community dwelling residents aged 15-64 were recruited.
Main outcome measures: 12-month diagnoses of DSM-IV psychiatric disorders including mood, anxiety, and substance use disorders were assessed using a validated Persian translation of the Composite International Diagnostic Interview (CIDI; version 2.1). The Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I) was administered by a psychiatrist on subjects screened positive for the presence of a psychotic disorder. The severity of psychiatric disorders was determined using criteria that included markers for disability, particular diagnoses and suicide attempts.
Results: The response rate was 86.2%. The 12-month weighted prevalence of "any psychiatric disorder" was 23.6% [95% confidence interval (CI): 22.4-24.8] with 26.5% of women and 20.8% of men having one or more psychiatric disorders. The most common category of psychiatric disorders was any anxiety disorder (15.6%) and the most prevalent particular disorder was major depressive disorder (12.7%), followed by generalized anxiety disorder (5.2%) and obsessive-compulsive disorder (5.1%). A 12-month psychotic disorder was observed in 0.5% of the population (95% CI: 0.33-0.66). Almost two-thirds (63.8%) of individuals with a mental disorder had moderate or serious illness. Unemployment, being widowed/divorced and urban living were associated with a greater likelihood of 12-month disorders; while, higher socioeconomic status and having a university degree were associated with a lower likelihood.
Conclusion: The high prevalence of psychiatric disorders, particularly major depression, merits further attention in the country's mental health policy and program planning.