Body mass index undergoes a substantial change in some psychiatric disorders. This study aimed to explore the status of body mass index (BMI) in different psychiatric disorders in a national survey among children and adolescents and to identify the role of gender in this regard. A total of 30 532 children and adolescents were randomly selected using cluster sampling method with equal blocks of three age groups and two genders. Psychiatric disorders were assessed using a standardized face-to-face diagnostic interview of Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (KSADS-PL), and Body Mass Index (BMI) was measured for each participant. In this study, 22 730 children and adolescents (109 46 boys and 11784 girls), with valid data of BMI, completed the KSADS-PL interview. The prevalence of psychiatric disorders was 21.2% among underweight participants, 22.8% among overweight participants, and 22.2% among obese participants, which was significantly higher than normal weight participants with 19.6% (X2 = 17.55; p = 0.001). In boys’ subgroup, depression and separation anxiety were mostly seen among the underweight category, while tic disorder was mostly seen in the obese category. In girls’ subgroup, on the other hand, generalized anxiety was mostly observed in the underweight category, while oppositional defiant disorder (ODD), depression, and mental retardation were mostly observed in the obese category. In total, the highest mean BMI rates were among the children and adolescents with alcohol abuse disorder, mania, and panic disorder. However, the lowest BMI rates were among those with attention deficit hyperactivity disorder (ADHD), separation anxiety disorder (SAD), and enuresis. This study gives an overall picture of BMI status in different psychiatric disorders according to gender. Furthermore, in a multidisciplinary approach, the results of this study drew the attention of child psychiatrists to the status of BMI in their clients.
Copyright © Psychiatry & Psychology Research Center, Tehran University of Medical Sciences.