Psychiatric disorders in children with intellectual disability.

We investigated psychiatric disorders in intellectually disabled children; the prevalence rate and types of psychiatric disorders, and the association of psychiatric disorders with sex, residence type, level of disability, and epilepsy were examined. The population comprised 155 intellectually disabled children. Medical information was obtained from case files, which indicated that a psychiatric disorder had previously been diagnosed for 11% of patients. A careful re-examination of the case files revealed a psychiatric disorder for 33%. The criteria of a psychiatric ICD-10 diagnosis were fulfilled by 23%, and a further 10% had an unspecified mental disorder. The most common diagnoses were pervasive developmental disorders and hyperkinetic disorders. The former were less common among children with mild intellectual disability. In conclusion, about one-third of children with intellectual disability have a psychiatric disorder which needs to be taken into account in treatment.