The adverse effects of long-term exposure to antipsychotics among older people with intellectual disabilities: a scoping review

Background: Antipsychotics are among the medications most prescribed to older adults with intellectual disabilities despite limited evidence to support their safety and efficacy in this population. Antipsychotics are associated with a significant burden of long-term adverse effects including movement disorders, metabolic and cardiovascular adverse effects, sedation and anticholinergic effects. This scoping review aims to evaluate the current extent of the literature relating to adverse effects of long-term antipsychotic use in older adults with intellectual disabilities and identify any existing gaps.  Methods: The review was conducted in line with the framework for scoping reviews proposed by Arksey and O’Malley. A systematic literature search was carried out, including searches of PubMed, Cochrane Library, ScienceDirect, Embase, PsycINFO and grey literature databases. Reference lists of studies were also reviewed as part of the search. Studies were included in the review if they related to adults over 40 years of age with an intellectual disability who had been taking antipsychotic medication for at least 3 months. Results: A total of 13 studies were identified for inclusion in the review. These included retrospective reviews,observational studies, case reports, cohort studies and cross-sectional studies. Adverse effects reported include extrapyramidal symptoms, cardiovascular and metabolic effects, and case reports of rhinorrhoea, hypothermia and ischaemic colitis. Increasing age was associated with a greater burden of adverse effects in some studies. Conclusion: The available evidence on the adverse effects of long-term antipsychotic use in older adults with intellectual disabilities is weak and conflicting. The studies included were generally of poor quality with numerous limitations including small sample sizes and lack of control groups. More research is needed to inform understanding of adverse effects associated with long-term antipsychotic use in this population.