Psychometric properties of the psychopathology instrument for mentally retarded adults.

One hundred and ten adults, from borderline to severe levels of mental retardation, were assessed through the outpatient clinic of a university-affiliated mental health center and a large state psychiatric hospital. These patients were included only after they had demonstrated the ability to respond to questions of similar difficulty to those presented in the Psychopathology Instrument for Mentally Retarded Adults. This measure was designed by the authors based on DSM III criteria, and covered seven types of psychopathology including schizophrenia, depression, psychosexual disorders, adjustment disorder, anxiety, somatoform disorders, and personality problems. In the present study the psychometric properties of the scale were reviewed and/or evaluated including internal consistency of items and test-retest reliability, and factor analysis.