Characteristics of schizophrenia among persons with severe or profound mental retardation.

The symptoms of schizophrenia were examined in a residential sample of adults with severe or profound mental retardation. Three groups were compared: those with a significant elevation on the schizophrenia subscale of the Diagnostic Assessment for the Severely Handicapped (DASH-II) and a psychiatric diagnosis of schizophrenia; those with a significant elevation on the same subscale but no formal diagnosis of schizophrenia; and those with no elevation on any of the DASH-II subscales. A one-way analysis of variance showed statistically significant differences between the groups. Symptoms of schizophrenia among those in the first group were found to fall mainly into the categories of reality distortion and disorganization, with less evidence of negative symptoms.