A review on the mental health needs of adults with intellectual disability (ID) and autism spectrum disorder (ASD) published just over 10 years ago found a limited evidence base for pharmacological intervention in this group. The aim of this paper was therefore to review the evidence in the subsequent 10 years, with a focus on polypharmacy use in adults who have both ID and ASD. A critical literature review of key papers published from 2009 to 2021 was undertaken on adults with both ID and ASD and related to psychopharmacology, polypharmacy, antipsychotics, antidepressants, mood stabilisers and anxiolytics interventions in improving symptoms. After excluding articles for lack of relevance, a review with a focus on the use of polypharmacy was carried out on the retrieved results. Four papers were identified as relevant to adults with both ID and ASD. Three main themes were identified in the review, including the application of pharmacogenetics, the influence of national policy on prescribing practices and safety concerns in a population with multiple health comorbidities. The past decade has produced a small increase in the evidence base on psychopharmacology use in adults with ID and ASD. However, more evidence on the effectiveness and impact of long-term polypharmacy use is required.
Keywords: autism spectrum disorder; comorbidity; intellectual disability; polypharmacy; prescribing; psychopharmacology.