Background: Depressive episode is one of the most common types of psychiatric illness that occurs in adults with intellectual disabilities.
Methods: A comprehensive literature search was undertaken using Medline, PsychLIT and hand-searching of key journals. This paper reviews the evidence and integrates findings, to report how evidence relates to the development of the new Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation[DC-LD] depressive episode criteria.
Results: This area is better researched than many others, providing evidence on clinical symptomatology and presentation. In view of the lack of utility of standard diagnostic criteria developed for use with the general population, and set within the historical context, there are clearly identified reasons for the introduction of DC-LD. The depressive episode category has been informed by the evidence, and field trials showed excellent validity compared with the gold standard of learning disabilities psychiatric assessment.
Conclusion: The DC-LD depressive episode category may improve clinical diagnosis and facilitate research. Its usefulness and limitations are yet to be determined in detail.