Background: The frequency and intensity of physical activity are directly related to health in the general population. However, to our knowledge, no study has looked at that relationship in people with intellectual disability. Method: The aim of this study was to determine whether there were differences in the health of 407 people with…

Since their separation as independent diagnostics, autism spectrum disorders (ASD) and schizophrenia spectrum disorders (SSD) have been conceptualized as mutually exclusive disorders. Similarities between both disorders can lead to misdiagnosis, especially when it comes to average-IQ adults who were not identified during childhood. The aim of this…

Background: Pervasive developmental disorders (PDDs) were originally conceptualised as a form of ("infantile") psychosis. Recently, the disorders have been viewed as separate constructs. However, there is evidence of overlapping psychopathology, pathophysiology, and occurrence of the two syndromes. Methods: A historical overview is provided. A…

Studies determining the prevalence of autistic children are reviewed. The findings of the survey, conducted in British Columbia in 1978 for the purpose of enumerating the children identified as autistic, psychotic, or schizophrenic, are presented. Among variables described are age, sex, school placement, manner of communication, and existence of…

Distributions of psychiatric classifications among 42,479 persons with mental retardation were reviewed to determine relative rates of disorders for persons with both mental retardation and mental disorder. Analyses indicated that rates of reported schizophrenic and psychotic disorders were generally higher than expected relative to rates of other…