(HealthDay News) — Use of tobacco and/or cannabis, particularly co-use of both substances, is associated with poor mental health, according to a study published online Sept. 13 in PLOS ONE.

Nhung Nguyen, PhD, from the University of California, San Francisco, and colleagues used data from the digital COVID-19 Citizen Science Study (2020 to 2022) to examine associations between self-reported use of tobacco and/or cannabis with anxiety and depression.

The researchers found that compared with nonuse, the adjusted odds of mental health disorders were highest for co-use (odds ratios [95% confidence intervals], 1.89 [1.64 to 2.18] and 1.77 [1.46 to 2.16] for anxiety and depression, respectively). Co-use (odds ratio, 1.35; 95% confidence interval, 1.08 to 1.69) and cannabis-only use (odds ratio, 1.17; 95% confidence interval, 1.00 to 1.37) were associated with higher adjusted odds for anxiety, but not for depression, compared with tobacco-only use. There were higher adjusted odds for both anxiety and depression associated with daily use (versus nondaily use) of cigarettes, e-cigarettes and cannabis.

“The findings suggest that coordinating tobacco and cannabis cessation with mental health treatment may be beneficial to address these comorbidities,” the authors write. “Specifically, providing mental health support and addressing polysubstance use (e.g., tobacco, cannabis, alcohol) among individuals with co-use are needed to facilitate successful cessation from tobacco and cannabis.”

Abstract/Full Text