Psychotropic medicines' prevalence, patterns and effects on cognitive and physical function in older adults with intellectual disability in Ireland: Longitudinal cohort study, 2009-2020

Background The frequent prescribing of psychotropics and high prevalence of polypharmacy among older adults with intellectual disabilities require close monitoring. Aims To describe change in prevalence, predictors and health outcomes of psychotropic use during the four waves (2009/2010, 2013/2014, 2016/2017, 2019/2020) of the Intellectual Disability Supplement to the Irish Longitudinal Study on Ageing (IDS-TILDA). Method Eligible participants were adults (≥40 years) with intellectual disabilities who participated in all four waves of IDS-TILDA and who reported medication use for the entire period. Differences between groups were tested using Cochran's Q test for binary variables and the McNemar-Bowker test for variables with more than two categories. Generalised estimating equation models were used to assess associations between psychotropic use, participants' characteristics and health outcomes. Results Across waves (433 participants) there were no significant differences in prevalence of psychotropic use (61.2-64.2%) and psychotropic polypharmacy (42.7-38.3%). Antipsychotics were the most used subgroup, without significant change in prevalence between waves (47.6-44.6%). A significant decrease was observed for anxiolytics (26.8-17.6%; P < 0.001) and hypnotics/sedatives (14.1-9.0%; P < 0.05). A significant increase was recorded for antidepressants (28.6-35.8%; P < 0.001) and mood-stabilising agents (11.5-14.6%; P < 0.05). Psychotropic polypharmacy (≥2 psychotropics) was significantly associated with moderate to total dependence in performing activities of daily living over the 10-year period (OR = 1.80, 95% CI 1.21-2.69; P < 0.05). Conclusions The study indicates an increase in usage of some classes of psychotropic, a reduction in others and no change in the relatively high rate of antipsychotic use over 10 years in a cohort of older adults with intellectual disabilities and consequent risk of psychotropic polypharmacy and medication-related harm.