Psychometric assessment of psychiatric disorders in people with learning difficulties (mental handicap): a review of measures.

Instruments designed to assess psychiatric disorders in people with learning difficulties (mental handicap) were critically reviewed from a psychometric perspective. Major trends were found in the assessment of psychopathology related to DSM-III and depressive disorders although research in other areas was patchy. Although some psychometrically sophisticated measures were identified the area was characterized by an absence of important psychometric data for many measures. Future research should attend to developing assessments of schizophrenia, psycho-sexual disorders, adjustment disorders and the validation of screening procedures and instrument formats. Future studies should include more people with severe and profound learning difficulties.