Psychiatric disorders in adolescents and adults with autism and intellectual disability: A representative study in one county in Norway

Psychiatric disorders and SGAP were found to be high both in the autism (53.2%) and ID-only group (17.4%). More than 50% of the autism and approximately 20% of ID-only group had SGAP. The differences were significant. The autism-psychiatric disorder interaction was significant. The largest differences between the prevalence in the autism and the ID-only group were shown in individuals with anxiety. The majority of the individuals in both study groups were afflicted with more than one psychiatric disorder. About 60% were found to have more than one disorder. The individuals with more severe psychiatric symptoms had higher degrees of diagnostic overlap. Having an intellectual disability seem to imply high risk for developing adjustment problems, and it seems especially difficult for individuals with autism to master every-day challenges.