The Psychopathology Instrument for Mentally Retarded Adults. Internal consistencies and relationship to behaviour problems.

The Psychopathology Instrument for Mentally Retarded Adults, a recently developed, empirically derived measure of psychiatric disturbance for the mentally handicapped, gives a total of eight scales which correspond to DSM-III diagnostic categories. This paper reports its psychometric properties in a British population and the psychometric properties of three scales derived by factor analysis. The internal consistencies of the scales were only barely acceptable in this sample and less acceptable than in previous studies.