A criterion validity study of the schizophrenia subscale of the Psychopathology Instrument for Mentally Retarded Adults (PIMRA).

Sixty-five mildly to moderately mentally retarded adults from institutional and community placements in Louisiana and Texas with DSM diagnoses of schizophrenia, depression, or no psychopathology were recruited. The primary goal was to establish the validity of the PIMRA's schizophrenic subscale for diagnosing mentally retarded adults. In addition, validity of the depression subscale was replicated. Assessment measures included the informant version of the Psychopathology Instrument for the Mentally Retarded (PIMRA), DSM-III-R checklists for schizophrenia and depression, and a drug response rating. Univariate and multivariate analyses were conducted, as were interrater reliability on all measures. The schizophrenia and depression subscale of the PIMRA were validated. Implications of the research and directions for future study are presented.