The prevalence of challenging behaviour (CB) was 18.1% in this total population study. Stereotypy was the most frequent type of CB. Communication difficulties and severe-profound intellectual disabilities were most systematically related to the presence of CB. Establishing the effect of multiple risk factors is likely to identify people who are priority for interventions. Addressing multiple, rather than singular risks, is likely to be more efficacious. We tested five different methods of putting together a multiple risk index. All methods provided a reasonable association with CB. The most user-friendly method was the additive cumulative risk index (CRI). Limitations This is a cross-sectional design which enabled factors currently associated with CB to be identified for the whole cohort, but these variables may not be those conferring risk for the development or maintenance of CB over time. Future longitudinal research is required to replicate these CRI analyses before concluding about the CRI method with the highest predictive validity.

The use of a total population sample identified via multiple routes is less likely to overestimate prevalence rates of medication use. Current challenging behaviour was a predictor of medication use after controlling for other variables. Data indicate that there may be differences in prescribing patterns associated with different topographies of challenging behaviours.

Purpose of Review To summarise findings about the prevalence and correlates of challenging behaviour in adults with intellectual disabilities from robust research. We also describe findings on the interplay between challenging behaviour and mental health. Recent Findings Recent studies that have utilised psychometrically evaluated tools, with clear operational definitions, show similar findings on the prevalence of challenging behaviour of about 1 in every 5-6 adults known to services. We describe common correlates identified such as communication impairments, severity of intellectual disability, and living in institutional settings or congregate care. We also describe the complex and multifaceted relationship between challenging behaviour and mental health. Summary Based on recent studies, we propose a revised framework model to help understand challenging behaviour. We propose a number of areas where more research is required, particularly the development of risk tools clinicians can utilise in practice. Keywords Intellectual disability. Challenging behaviour. Prevalence. Correlates. Risk factors. Mental health This article is part of the Topical Collection on Intellectual Disabilities

Background Adults with intellectual disability (ID) are prescribed high levels of medication, with polypharmacy and psychotropic polypharmacy common. However, reported rates vary between studies, and there has been an over-reliance on obtaining data from convenience samples. The objective of this study was to determine the prevalence of medication use and polypharmacy in a population-level sample of adults with IDs. Factors associated with polypharmacy and psychotropic polypharmacy are explored. Methods We used a total population sample of 217 adults with IDs known to services in Jersey (sampling frame n = 285). The Anatomical Therapeutic Chemical classification system was used to categorise medications that participants were currently taking on a regular basis. We examined associations of polypharmacy and psychotropic polypharmacy with socioeconomic status, health and demographic variables using univariate and multivariate analyses. Results A total of 83.4% of participants were prescribed medication, with high doses common. Of the participants, 38.2% were exposed to