[Obsessive-compulsive disorder in children and adolescents: literature review. Part I].

The literature on obsessive-compulsive disorder (OCD) in children and adolescents is reviewed. The disorder is characterized by obsessions (recurrent troublesome thoughts) and compulsions (ritualized thoughts or behaviors performed repetitively in response to an irresistible urge). OCD is far more common among children and adolescents than was previously believed. Good epidemiological studies from different parts of the world are still needed to determine if prevalence is equally high. Boys seem to have an earlier age of onset of OCD than girls. Male female ratio changed with age of onset, with males predominating in early onset and increasing numbers of females occurring during adolescence. Increasing evidence supports a neurobiological theory for etiology of OCD, specifically a frontal lobe--basal ganglia dysfunction.