On average, 49–63% of people with intellectual disabilities and/or autism spectrum disorder (ASD) are prescribed psychotropic medications to treat psychopathology, including psychiatric illness, behaviours that challenge and the core symptoms and associated behaviours of these developmental disorders. In many cases, psychotropics, particularly antipsychotics, are used off-label without a proper indication, particularly to manage behaviours that challenge. The RCTs show moderate evidence supporting the efficacy of low-dose risperidone and some preliminary evidence for aripiprazole in treating behaviours that challenge among children with ASD and/or intellectual disabilities. The RCT-based evidence for the other psychotropics is equivocal, so no definitive conclusions can be made on their efficacy. Polypharmacy and the use of high doses of antipsychotics are prevalent in this population, leading to the risk of adverse events and drug–drug interactions. Despite various national and international guidelines, and government initiatives encouraging reduced psychotropic use, there is little evidence of this happening; on the contrary, the use of antidepressants, mood stabilisers and benzodiazepines may be increasing. A concerted multi-agency effort is urgently needed to address this significant public health concern of the overmedication of people with intellectual disabilities and/or ASD.

Up to a fifth of people with intellectual disabilities display challenging behaviour that has a significant impact on their health and quality of life. Psychotropic medication does not appear to confer any clinical benefits beyond risk reduction in acute situations. However, very few non-pharmacological treatments have clear evidence of clinical and cost-effectiveness and there is therefore often a dearth of advice as to which components or interventions would be helpful. To our knowledge no single model has been developed to provide a clear path from understanding the behaviour to the implementation of a therapeutic approach for such a complex clinical problem. In this article we describe a stepped-care model that needs to be further operationalised in the assessment and management of behaviours that challenge in adults with intellectual disabilities.