Pica in people with intellectual disability: a literature review of aetiology, epidemiology and complications

Pica is a common problem in people with intellectual disability. Its significance can be under-recognised by carers and healthcare professionals. Pica can be a manifestation of a range of medical conditions and can lead to a variety of complications including lead and nicotine toxicity, surgical intervention requirements, and parasitic infestation. The literature is reviewed for references to the epidemiology, aetiology and complications of pica in people with intellectual disability. Studies of the prevalence of pica in institutional and community settings show lower rates in the community (0.3-14.4%), although rates remain quite high in institutionalised populations (9-25%). The psychological, cultural and medical theories on aetiology are explored, along with complications. Areas for further research are highlighted.