In conducting this study, the researchers were able to tap into an existing data source: the COVID-19 Citizen Science Study – a mobile app developed by UCSF researchers that contained a wealth of data, including mental health status and substance use, collected from participants around the country through online surveys.
Association Between Tobacco and Cannabis with Mental Illness
They analyzed responses from 53,843 Americans from March 2020 to April 2022 who answered questions about tobacco and cannabis use over a 30-day period, and paired this with monthly assessments of the participant’s mental health status.
Among people who used both substances, 26.5% reported anxiety and 28.3% reported depression. Percentages of anxiety and depression were only 10.6% and 11.2% in people who used neither substance. Those who only used tobacco had higher rates of anxiety and depression than those who did not.
The study did not delve into whether mental health conditions are exacerbated or triggered by tobacco or cannabis use or vice versa.
“Some believe that cannabis might mitigate against the ill effects of tobacco,” said the paper’s senior author, Gregory Marcus, MD, MAS, professor of medicine and associate chief of research for the Division of Cardiology, “But, these data suggest the combination is particularly harmful to mental health.”
- Uni-Morbid and Co-Occurring Marijuana and Tobacco Use: Examination of Concurrent Associations with Negative Mood States