The Relationship between Autism and Psychiatric Disorders in Intellectually Disabled Adults.

Abstract Intellectual Disability (ID) shows a high comorbidity with psychiatric disorders with a great variability in the prevalence rates. An important subgroup is represented by subjects with ID and autism or other autistic spectrum disorders (PDD). The purpose of the present study was to assess PDD with specific screening tools in a population of people with ID and compare the groups with or without PDD through the administration of a psychopathological scale in order to verify the differences of psychiatric disorders’ rates. The study was conducted on 90 subjects attending daily centres or residential centres in Florence, Italy. In order to assess the presence of PDD, the PDD-MRS was administrated, while for the assessment of the psychopathological aspects we have used the DASH-II. The presence of a psychiatric disorder has a significant effect on anxiety, depression and organic syndromes and statistically significant differences have been registered in many DASH-II subscales. The statistical comparison between the two groups shows that PDD was clearly correlated with an increased presence of psychiatric disorders. The variable PDD could be considered as a vulnerability factor for psychiatric disorders. However there was still the need to focus on categorical diagnoses, in order to increase our knowledge about the concept of vulnerability in people with ID.