Medicinal cannabis did not improve depression or anxiety in cancer patients but did help appetite

What the researchers found

No clinically significant effects on depression, anxiety, or stress. Higher-dose synthetic THC increased anxiety events (OR 2.0, p<.001). Medicinal cannabis increased likelihood of improved appetite 12-fold (OR 12.3, p<.001) and reduced appetite loss severity. No effects on emotional functioning, mood changes, confusion, or quality of life.

Why it matters

Many cancer patients use cannabis hoping it will help their mental health. This meta-analysis shows that while cannabis may benefit appetite, it does not appear to help with depression, anxiety, or stress in cancer, and higher THC doses may actually worsen anxiety.

The numbers in context

15 studies, 1,898 participants. 18 interventions tested. Appetite improvement OR: 12.3 (p<.001). Higher-dose synthetic THC anxiety events OR: 2.0 (p<.001). No significant effects on depression, anxiety, stress, mood, QoL, or GI symptoms.

How the study worked

Systematic review and meta-analysis of 15 intervention studies (11 RCTs, 4 non-randomized, N=1,898) from 5 databases through May 2023. Pooled with Review Manager using random-effects models. Evidence appraised with Cochrane tools and GRADE.

What this study cannot tell us

Most interventions used synthetic THC (70%), which may differ from whole-plant cannabis. GRADE confidence was low to very low for most outcomes. Small number of studies for some outcomes. Heterogeneous cancer types and treatment contexts.

How to read the evidence

Systematic review and meta-analysis with GRADE assessment. Most findings had low or very low confidence due to study quality and imprecision.

When this study was published

Published in 2024 in Maturitas, covering literature through May 2023.

The bigger picture

The appetite finding is notable because cancer cachexia is a major clinical problem. But the lack of benefit for mental health outcomes challenges the assumption that cannabis broadly improves wellbeing in cancer patients. Targeted use for appetite rather than general symptom management may be more appropriate.

Questions still open

• Would whole-plant cannabis products perform differently than synthetic THC for cancer-related anxiety? Is the anxiety-worsening effect of high-dose THC clinically significant? Could CBD-dominant products help mental health in cancer without the THC anxiety risk?

Common questions

Read the original research

Does medicinal cannabis affect depression, anxiety, and stress in people with cancer? A systematic review and meta-analysis of intervention studies.

Maturitas, 184, 107941

Citation

Crichton, Megan; Dissanayaka, Thusharika; Marx, Wolfgang; Gamage, Elizabeth; Travica, Nikolaj; Bowers, Alison; Isenring, Elizabeth; Yates, Patsy; Marshall, Skye. (2024). Does medicinal cannabis affect depression, anxiety, and stress in people with cancer? A systematic review and meta-analysis of intervention studies.. Maturitas, 184, 107941. https://doi.org/10.1016/j.maturitas.2024.107941

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