Autism spectrum disorders among adolescents and adults and comparison with schizophrenia

Abstract

Objectives: Autism Spectrum Disorders (ASD) may be commonly misdiagnosed as schizophrenia due tocommon symptoms and accompanying psychotic manifestations in both adolescence and adulthood. Thepurpose of this study is to examine and compare the autistic symptoms and positive and negative symptoms ofschizophrenia in cases diagnosed as Autism Spectrum Disorder.Methods: Twenty-one patients between ages of 16-36 who have admitted to outpatient clinic have previouslybeen diagnosed as autism spectrum disorders (autistic disorder, Asperger Syndrome, pervasive developmentdisorder not otherwise specified) according to DSM-IV diagnosis criteria, have an IQ of 50 or above, havebeen included in the study. Control group have been composed of 21 patients between ages of 21-39 who havebeen diagnosed as schizophrenia according to DSM-IV diagnosis criteria and have an IQ of 50 or above.Psychiatric assessment has been made with Childhood Autism Rating Scale (CARS), Scale for the Assessmentof Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms (SANS), SCID-I and WAIS.Results: The negative symptoms of ASD are found to be higher than schizophrenia cases where as the positivesymptoms of schizophrenia cases are found to be higher than ASD cases. Twenty percent (n = 4) of OSB casesdo not meet autism symptoms while none of the schizophrenia cases meet autism symptoms. In one case ofthe ASD group, additional schizophrenia diagnosis was present.Conclusions: In this study, it has been found that negative symptoms of schizophrenia are widely observed inadolescent and adult patients followed with ASD diagnosis. Consequently, autism spectrum disorders aremanifested common symptoms with schizophrenia in adolescence and adulthood.