Background: Emerging research suggests the COVID-19 pandemic has resulted in a significant increase in self-reported isolation and loneliness in a large proportion of the population. This is
particularly concerning given that isolation and loneliness are associated with increased cannabis use, as well as using cannabis to cope with negative affect. Objective: We investigated whether
self-isolation due to COVID-19 and using cannabis to cope with depression were unique and/or interactive predictors of cannabis use during the pandemic, after controlling for pre-pandemic levels of cannabis use. Method: A sample of 70 emerging adults (mean age ¼ 23.03; 34.3% male) who used both alcohol and cannabis pre-pandemic completed measures of cannabis use (i.e.,
quantity x frequency) and a novel COVID-19 questionnaire between March 23 and June 15, 2020. Pre-pandemic cannabis use levels had been collected four months earlier. Results: Linear
regressions indicated self-isolation and coping with depression motives for cannabis use during the pandemic were significant predictors of pandemic cannabis use levels after accounting for
pre-pandemic use levels. There was no interaction between coping with depression motives and self-isolation on cannabis use during the pandemic. Conclusions: Those who engaged in self-isolation were found to use 20% more cannabis during the pandemic than those who did not. Our results suggest that self-isolation is a unique risk factor for escalating cannabis use levels during
the pandemic. Thus, self-isolation may inadvertently lead to adverse public health consequences in the form of increased cannabis use.