The relationship between Asperger's syndrome and schizophrenia in adolescence

Asperger's syndrome (AS), a pervasive developmental disorder (PDD), has nowadays been widely advocated in media. Therefore, psychiatrists treating adolescents frequently meet patients as well as their families reporting of symptoms resembling those of Asperger's syndrome. It is known that symptoms of Asperger's syndrome have some overlap with those of schizophrenia, but less is known about comorbidity between these two syndromes. We describe a sample of 18 adolescents with early onset schizophrenia. Diagnosis of schizophrenia was based on assessment with Kiddie Schedule for Affective Disorders and Schizophrenia. The diagnostic interview for Social and Communication Disorders version 11 was used to assess autism spectrum disorders. Ten adolescents fulfilled symptom criteria of Asperger's syndrome after the onset of schizophrenia, while only two persons had Asperger's syndrome before the onset of schizophrenia, a prerequisite for diagnosis. 44% of the adolescents fulfilled the diagnosis of some PDD in childhood. Most of them were, however, unrecognized before the onset of schizophrenia. On the other hand, all 18 patients had one or more symptoms of PDDS in adolescence. Adolescents with schizophrenia have often symptoms consistent with AS, although only few of them have fulfilled the diagnostic criteria in their childhood, a prerequisite for the diagnosis of AS. There is a risk for misdiagnosis of adolescents with autistic symptoms if detailed longitudinal anamnesis is not obtained.