The COVID-19 pandemic resulted in families self-isolating under incredible stress. Viral containment strategies included school closures with parents left to homeschool their children with few supports from the educational system. Recent data show that those with children at home were more likely to drink heavily during the pandemic (Rodriguez et al., in press). Gaps remain, however, in understanding whether these effects are due to the stresses of homeschooling and whether they extend to cannabis use. Seven-hundred-and-sixty Canadian romantic couples (total N=1520 participants; mean age = 57 years; 50% women) who were self-isolating together during the month of April 2020 were recruited through Qualtrics Panel Surveys. Measures were completed retrospectively in early July 2020; participants were asked to report on their feelings and behavior in April 2020 during lockdown. They completed the GAD-7 (Spitzer et al., 2006) and the PHQ-9 (Kronke et al., 2001) to assess anxiety and depression, brief versions of four subscales of the COVID-19 Stress Scales (Taylor et al., 2020) to assess stress around the pandemic, and the Life Orientation Test – Revised (Chiesi et al., 2013) to assess optimism. They completed a measure of role strain (Statistics Canada, 2015) and a measure of conflict with their partner (Murray et al., 2003). They also completed a validated measure of cannabis use frequency and quantity (Cuttler et al., 2017), as well as two validated items from the Brief Cannabis Motives Measures (Bartel et al., 2020) to assess cannabis use to cope with depression and anxiety, respectively. All measures were completed for a 30-day timeframe during the month of April. Participants also reported on whether they were homeschooling one or more children in Grade 1-12 during the month of April. Data was analyzed with a one-way (homeschooling group) Analysis of Covariance (ANCOVA) controlling for group differences in age; a Bonferroni-correction was applied to account for multiple tests. Compared to those who did not homeschool (n=1116), those who did homeschool (n=404) experienced significantly more depression (p=.001), more COVID-19-related stress around socioeconomic consequences (p<.001) and traumatic stress (p<.001), and less optimism (p=.002). And those who homeschooled experienced more role strain between their home and work responsibilities (p<.001) and more conflict both toward and from their partner (p’s<.001) than those who did not homeschool. Those who homeschooled also used cannabis significantly more frequently in the month of April than those who did not homeschool (p=.003). Compared to cannabis users who did not homeschool (n=122), cannabis users who did homeschool (n=61) reported more frequent cannabis use to cope with both depression and anxiety (p’s = .003). These findings suggest that unintended consequences of our societal viral containment strategies include more depression, pessimism, role strain, inter-parental conflict, and certain COVID-related stresses, and extend to more frequent cannabis use to cope with negative affect, among parents required to homeschool during the pandemic. These unintended mental health and substance misuse consequences for parents need to be considered when planning for an educational strategy in the fall and for any future waves of the pandemic.