A new study published in Frontiers of Psychiatry has used observational methods to investigate the antidepressant and anxiolytic effect of medicinal cannabis, concluding it may reduce symptoms of anxiety and depression. 

A US team led by Medical University of South Carolina neuroscientist Erin Martin engaged 368 cannabis users and 170 controls (non-users) who completed an online survey assessing anxiety and depressive symptoms, cannabis product use, quality of life and chronic pain. 

Participants completed a base-line survey and then additional follow-up surveys at three-month intervals. 

The participants’ self-reported symptoms were analysed against the Hospital Anxiety and Depression Scale (HADS), in which a score above eight indicates clinical concern (scores can reach up to 21).

Results indicated that at base-line, medicinal cannabis use was associated with lower self-reported depression, but not anxiety, with this group also reporting superior sleep, quality of life, and less pain on average. 

However, the study found that “initiation of medicinal cannabis during the follow-up period was associated with significantly decreased anxiety and depressive symptoms, an effect that was not observed in controls that never initiated cannabis use”. 

The study found these effects were strongest among participants using products with large amounts of CBD as opposed to THC.

While the study relied on participants self-reporting, the authors conclude “medicinal cannabis use may reduce anxiety and depressive symptoms in clinically anxious and depressed populations”.

They note that future research such as placebo-controlled studies are necessary to see if these findings are replicated and to further explore the potential efficacy of CBD in the treatment of anxiety and depression.

Hannah Adler

Hannah is a communications professional and early-career researcher in the disciplines of health communication and health sociology. She is a PhD student at Griffith University currently writing a...