Personality disorder in intellectual disability

Purpose of review To examine recent research evidence and reviews about personality disorder in intellectual disability, focusing on papers published from March 2002 to March 2003. Recent findings The year in review has seen a stock-take of the limited research on personality disorder in intellectual disability. Research to date has been hampered by methodological shortcomings, hence the rubbery figures on prevalence. There has been much discussion about the challenges in applying a number of diagnostic tools, for which there are limited data on reliability and validity, with several small-scale studies illustrating these difficulties. A number of new diagnostic instruments have been developed, although for some there are problems with construct validity. This reflects the lack of conceptual clarity about the fundamental constructs of personality disorder in intellectual disability and the blurring of the boundaries between personality, psychiatric and behaviour disorders. Advances have been in the area of personality development and there are some preliminary studies into the childhood antecedents to adult personality disorder in intellectual disability. Intervention studies are rare and are limited to clinical case studies. Summary The recent upsurge in interest in personality disorder in intellectual disability and methodological developments should enable future research into the development, prevalence, and outcomes of interventions to inform clinical practice and service provision.