Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) and psychiatric phenotypes

The concept of behavioural phenotypes is reviewed, with emphasis on the need to research reasons for heterogeneity. The classification of emotional, behavioural, linguistic and cognitive abnormalities associated with genetic disorders may be improved through the use of the Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation. Examples of such abnormalities are discussed, showing how more accurate descriptions can result in improved diagnosis and treatment.