A systematic review of personality disorder amongst people with intellectual disability with implications for the mental health nurse practitioner

Aims and objectives. This paper reviews and summarises the literature on assessment, diagnosis and management of personality disorder in people with intellectual disability. It will proceed to argue the implications of a mental health nurse practitioner in clinical practice. Background. Personality disorder is a potentially severe and disabling condition causing significant distress as well as presenting considerable challenges for service providers. Diagnosis in people with intellectual disability is controversial. However, it is considered that this population is at greater risk of these disorders. There is, however, little research on which to base clinical interventions or service planning. Design. Systematic review. Methods. A literature search of electronic data was undertaken in April 2007 using CINAHL, AMED, Medline, PsycINFO, EMBASE and Cochrane Library. Other sources included Google Scholar, hand searching of reference lists and texts and search of relevant websites. Results. The literature on personality disorder in intellectual disability is notable for its paucity. The limited evidence available suggests that this population is at greater risk of personality disorder and that assessment and diagnosis is complex and often overshadowed by the intellectual disability. Few papers address treatment, there are no trial‐based studies and it has not been established whether results can be extrapolated from research in the general population. Conclusions. The issue of personality disorder in people with intellectual disability is shrouded in controversy with a dearth of robust evidence to inform assessment or therapeutic care. Personality disorder does, however, provide a basis for decisions on type and intensity of support required for this population who have significant levels of unmet need. Relevance to clinical practice. Some people with an intellectual disability and personality disorder can live in the community with specialist support. The mental health nurse practitioner has the potential to provide people with dual diagnostic support needed to enhance the capacity of the service system to meet the needs of this complex and difficult population.