BackgroundEvidence for worsening mental health among individuals with intellectual and developmental disabilities (IDD) during COVID-19 sparked concerns for increased use of psychoactive medications. ObjectiveTo examine the impact of COVID-19 on psychoactive medication use and clinical monitoring among individuals with IDD in Ontario, Canada. MethodsWe conducted a repeated cross-sectional study among individuals with IDD and examined weekly trends for psychoactive medication dispensing and outpatient physician visits among those prescribed psychoactive medications between April 7, 2019, and March 25, 2023. We used interventional autoregressive integrated moving average models to determine the impact of the declaration of emergency for COVID-19 (March 17, 2020) on the aforementioned trends. ResultsThe declaration of emergency for COVID-19 did not significantly impact psychoactive medication use among individuals with IDD. Provision of clinical monitoring remained relatively stable, apart from a short-term decline in the weekly rate of outpatient physician visits following the declaration of emergency for COVID-19 (step estimate: 21.26 per 1000 individuals [p < 0.01]; ramp estimate: 0.88 per 1000 individuals [p = 0.01]). When stratified by mode of delivery, there was a significant shift towards virtual care (step estimate: 78.80 per 1000 individuals; p < 0.01). The weekly rate of in-person physician visits gradually increased, returning to rates observed prior to the COVID-19 pandemic in January 2023. ConclusionAlthough access to clinical care remained relatively stable, the shift towards virtual care may have negatively impacted those who encounter challenges communicating via virtual mediums. Future research is required to identify the support systems necessary for individuals with IDD during virtual health care interactions.