The impact of COVID-19 on autism research: A cross-sectional analysis of discontinued or suspended clinical trials

Due to uncertainties associated with the COVID-19 public health crisis, several clinical trials had to be withdrawn or postponed. Our investigation aimed to assess the rate of discontinuation of clinical trials focusing on Autism Spectrum Disorder. Of the 197 registered trials included in our systematic review, 15 (7.6%) were discontinued, with nearly half of these explicitly citing COVID-19 as their reason for discontinuation. Pharmacological trials were six times more likely to be discontinued during the pandemic than non-pharmacological studies. The difference between the likelihood of discontinuation was statistically significant (OR: 6.13; 95% CI: 1.22–30.71). There was no evidence of association between funding source and reasons for discontinuation. Limitations, along with implications for future trials are discussed. Lay Summary: We investigated the impact of the COVID-19 pandemic on the discontinuation rate of autism clinical trials. We found that drug trials were six times more likely to be discontinued during the pandemic compared to behavioral, diagnostic, and nutritional trials. The overall discontinuation rate was notably lower in autism clinical trials than in other areas of medical research. We recommend an examination of the methodology of the continued autism trials to assess their applicability in other fields.