Lifetime prevalence, comorbidities, and Sociodemographic predictors of post-traumatic stress disorder (PTSD): the National Epidemiology of Iranian Children and adolescents Psychiatric disorders (IRCAP).

OBJECTIVE: The aims of this study were to (a) evaluate the lifetime prevalence of post-traumatic stress disorder (PTSD) according to sociodemographic characteristics, (b) determine sociodemographic factors associated with PTSD, (c) estimate the lifetime prevalence rates of comorbidities by age and gender, and (d) assess the proportion of traumatic events in the non-PTSD sample and the PTSD sample, according to gender.

METHODS: The data used for the present study were obtained from the IRCAP study which was a cross-sectional, community-based study on 29,250 children and adolescents aged 6-18 years from all provinces of Iran, which was done using multistage cluster sampling. Trained psychologists conducted diagnostic interviews with parents, children, and adolescents using the Persian version of the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL).

RESULTS: In this study, the prevalence of PTSD across the sample population was 0.6% (95% CI, 0.5-0.7%). Higher rates of PTSD were observed among girls (0.7%, CI 0.5-0.8%), adolescents aged 15-18 years (0.8%, CI 0.6-1.0%), and participants who had unemployed (1.5%, CI 0.8-2.8%), or farmer fathers (1.1%, CI 0.5-2.5%). Of the participants with PTSD, 65.1% met the criteria for at least one other psychiatric disorder. PTSD had a high rate of comorbidity with oppositional defiant disorder (22.9%, CI 17.5-29.4%), generalized anxiety disorder (20.8%, CI 15.7-27.1%), separation anxiety disorder (20.3%, CI 15.2-26.6%), and major depressive disorder (19.8%, CI 14.8-26.0%). We found 9.5% of non-PTSD sample experienced at least one traumatic event. Witness to domestic violence was the most common traumatic event experienced by 32.8% of PTSD sample.

CONCLUSION: Our results in the prevalence, comorbidities, and sociodemographic factors associated with PTSD supported findings of previous studies that used a structured diagnostic interview. It is recommended to use purposive sampling and to investigate comorbidities of PTSD and type of traumatic events in a large clinical population.