Increased cannabis intake during the COVID-19 pandemic is associated with worsening of depression symptoms in people with PTSD

BACKGROUND: Some evidence suggests substance use affects clinical outcomes in people with posttraumatic stress disorder (PTSD). However, more work is required to examine links between mental health and cannabis use in PTSD during exposure to external stressors such as the COVID-19 pandemic. This study assessed mental health factors in individuals with self-reported PTSD to: (a) determine whether stress, anxiety, and depression symptoms were associated with changes in cannabis consumption across the pandemic, and (b) to contrast the degree to which clinically significant perceived symptom worsening was associated with changes in cannabis intake. METHOD: Data were obtained as part of a larger web-based population survey from April 3rd to June 24th 2020 (i.e., first wave of the pandemic in Canada). Participants (N = 462) with self-reported PTSD completed questionnaires to assess mental health symptoms and answered questions pertaining to their cannabis intake. Participants were categorized according to whether they were using cannabis or not, and if using, whether their use frequency increased, decreased, or remained unchanged during the pandemic. RESULTS: Findings indicated an overall perceived worsening of stress, anxiety, and depression symptoms across all groups. A higher-than-expected proportion of individuals who increased their cannabis consumption reached threshold for minimal clinically important worsening of depression, X(2)(3) = 10.795, p = 0.013 (Cramer’s V = 0.166). CONCLUSION: Overall, those who increased cannabis use during the pandemic were more prone to undergo meaningful perceived worsening of depression symptoms. Prospective investigations will be critical next steps to determine the directionality of the relationship between cannabis and depressive symptoms.