Depression in Adults with Intellectual Disability. Part 2: A Pilot Study

OBJECTIVES: To identify adults with intellectual disability (ID) with a depressive disorder referred to a tertiary consultation clinic for psychiatric assessment; to investigate common presenting features of depression in adults with ID; to assess the utility of visual analogue scale (VAS) measures of emotion/behaviour, the CORE measure of psychomotor disturbance, and substitutive diagnostic criteria in the assessment of depressive disorders in this patient group. METHOD: Over a 6-month period 47 patients were seen for psychiatric evaluation. Patients in whom a diagnosis of depression was made were further assessed using: VAS measures of depression, irritability, verbal aggression, physical aggression, temper outbursts, regressed behaviour; CORE measure of psychomotor disturbance; and substitutive diagnostic criteria designed by the authors. RESULTS: Ten patients were found to have a depressive disorder. Substitutive criteria resulted in a greater rate of diagnosis than standard DSM-IV criteria. The VAS measure of irritability was highly scored for all 10 depressed patients. All 10 depressed patients were assigned to the melancholic subgroup according to CORE score. CONCLUSIONS: Standard assessment measures and diagnostic criteria may require modification to enhance their utility in this patient group. Melancholic features require further investigation.