50 YEARS OF EPIDEMIOLOGIC STUDIES IN CHILD AND ADOLESCENT-PSYCHIATRY IN SWEDEN

In Sweden the first epidemiologic study on mental disorders in childre n and adolescents was made in 1945-46. Since then investigations have been made on different age groups using various methods to clarify the nature and magnitude of psychiatric morbidity in children and adolesc ents. During the last two decades the assessment of single behaviour d eviances and stress reactions has been replaced by studies on psychiat ric disorders according to the DSM system or using factor-analysed com posite clusters of behaviours. High rates of comorbidity show that the symptoms of young people are more diffuse than those of adults. The f requency of ''psychiatric cases'' varied depending on the methods used . Most studies rate 5-20% as behaviourally disturbed i.e. enough to ca use a problem to the child and/or his/her parents and teachers. Most s tudies state that boys have more behaviour deviances than girls before puberty. Girls have more problems during adolescence, especially depr essions and psychosomatic symptoms. Girls have more internalizing symp toms, while boys display more acting-out behaviours. Self-reported sym ptoms are generally more frequent than symptoms reported by parents. T eachers report the lowest frequencies. Severe psychopathology like ano rexia nervosa, major depressive disorders and psychoses are comparativ ely rare. The study of such conditions requires different methods than the study of adjustment problems and stress reactions.