The relationship between challenging behaviour and mental ill-health in people with intellectual disabilities: a review of current theories and evidence.

Challenging behaviours and problems of mental ill-health are common amongst people with intellectual disabilities. The article examines conceptual similarities and differences between these conditions, examines the data on comorbidity, and explores possible hypothetical relationships between behavioural and psychiatric disorder in this population. While there is little evidence at present to suggest that many of the challenging behaviours seen in people with intellectual disabilities are underpinned by problems of mental ill-health, only qualified conclusions are possible because of limitations in the quality and scope of existing research. A conceptual model for looking at the risk variables that may contribute to both conditions is suggested, and requirements for future research and current multi-disciplinary practice are outlined.