Some 10-15% of primary schoolchildren and 5-10% of adolescents suffer from a pronounced anxiety disorder. This term is applied to a state in which the intensity and duration of the condition is out of all proportion to the "trigger situation". In the case of young children the most common disorder takes the form of separation anxiety and nocturnal restlessness. In schoolchildren, school phobia, a fear of going to school and playing truant with the associated fear of detection are distinguished. In children, anxiety is the soil on which depression may develop, is the dominant symptom in obsessive-compulsive neurosis and histrionic syndrome and is often masked by aggression. Treatment depends on severity, nature and duration of the disorder, as well as on the age of the child, and involves such aspects as parent counseling and treatment, psychotherapy and pharmacotherapy.