This article provides a review of the magnitude of mental disorders in children and adolescents from community surveys across the world. Although there is substantial variation in the findings based on méthodologie characteristics of the studies, the findings converge in demonstrating that approximately one fourth of youth experience a mental disorder during the past year, and about one third across their lifetimes. Anxiety disorders are the most frequent, condition in children, followed by behavior disorders, then mood disorders and substance use disorders. Variation in the rates across the world can be attributed to both méthodologie factors and also to true cultural differences in the magnitude of childhood disorders. Girls have greater rates of mood and anxiety disorders, and boys have greater rates of behavior disorders, whereas there is an equal gender ratio for substance use disorders. ADHD and anxiety states begin in childhood, whereas the onset, of conduct disorder occurs at early adolescence, and mood disorders tend to begin in late adolescence.
