Advances in Mental Health and Intellectual Disabilities

Purpose – The Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) was introduced in 2003 in an attempt to improve accuracy of diagnosis in the intellectual disability population. The paper aims to apply this system to a sample of a population with intellectual disability to further investigate its usefulness in the clinical setting.

Design/methodology/approach – A sample of 50 patients within an intellectual disability service was identified. Each individual was interviewed by a registrar in psychiatry of intellectual disability in the presence of their key worker or a carer that knew the individual well. Chart notes were extensively reviewed for clearly documented history of psychiatric symptoms and behavioural difficulties. The information gathered was applied as per the DC-LD criteria to identify appropriate diagnoses. Previously documented diagnoses were also recorded for comparison purposes.

Findings – There was considerable discrepancy between the rates of psychiatric diagnoses after application of DC-LD and rates of previously documented diagnoses within the sample. Use of DC-LD led to the reclassification of many previously documented diagnoses, mainly as behavioural disorders. There were also discrepancies between rates of diagnosis of pervasive developmental disorders and Alzheimer's disease before and after use of DC-LD.

Originality/value – This study adds to the evidence regarding the usefulness of DC-LD in the intellectual disability population and also highlights the shortcomings of non-systematic methods of diagnosis. It was agreed that DC-LD criteria be applied to all service users in this population in the future.