Prevalence, comorbidities, and sociodemographic predictors of conduct disorder: the national epidemiology of Iranian children and adolescents psychiatric disorders (IRCAP).

The aim was to evaluate the lifetime prevalence of conduct disorder according to sociodemographic characteristics, determine the sociodemographic predictors of conduct disorder, and estimate the rates of comorbidities of psychiatric disorders in children and adolescents with conduct disorder by age and gender. The National Epidemiology of Iranian Children and Adolescents Psychiatric Disorders was a cross-sectional, general population-based study on 30,532 children and adolescents aged 6-18 years from all provinces of Iran, which was done using multistage cluster sampling. Iranian citizens aged 6-18 years who resided at least 1 year in each province were included, and children and adolescents with severe physical illnesses that prevented them to participate in the study were excluded. The sample weighting adjustment was used, since we had randomly selected the equal number of 1000 participants of each province from the urban and rural areas. Trained psychologists conducted diagnostic interviews with the adolescents and the children's parents using the Persian version of the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL). In this study, 54 children aged 6-9 years (0.58%, CI 0.47-0.77), 64 adolescents aged 10-14 years (0.57%, CI 0.47-0.77), and 117 adolescents aged 15-18 years (1.22%, CI 0.96-1.44) met the criteria of the lifetime conduct disorder. Conduct disorder was significantly more common in boys than in girls, and was significantly less prevalent among those participants whose fathers had no history of psychiatric hospitalization. Of the participants with conduct disorder, 83.4% met the criteria for at least one other psychiatric disorder. Conduct disorder had a high rate of comorbidity with oppositional defiant disorder (54.89%, CI 48.50-61.12), attention-deficit/hyperactivity disorder (32.34%, CI 26.68-38.56), tobacco use (20.43%, CI 15.77-26.04), and depressive disorders (18.30%, CI 13.88-23.74). Because of using the diagnostic instrument, we found a low total rate of prevalence for conduct disorder; however, higher rates of it were observed among boys and adolescents. Further studies are needed to explore the nature of comorbidities of conduct disorder and to consider them in a large clinical population.