Multinational Association of Supportive Care in Cancer (MASCC) guidelines: cannabis for psychological symptoms including insomnia, anxiety, and depression

Purpose: During the treatment of cancer, 18% of patients use cannabis for symptom management. Anxiety, depression, and sleep disturbances are common symptoms in cancer. A systematic review of the evidence for cannabis use for psychological symptoms in cancer patients was undertaken to develop a guideline. Methods: A literature search of randomized trials and systematic reviews was undertaken up to November 12, 2021. Studies were independently assessed for evidence by two authors and then evaluated by all authors for approval. The literature search involved MEDLINE, CCTR, EMBASE, and PsychINFO databases. Inclusion criteria included randomized control trials and systematic reviews on cannabis versus placebo or active comparator in patients with cancer and psychological symptom management (anxiety, depression, and insomnia). Results: The search yielded 829 articles; 145 from Medline, 419 from Embase, 62 from PsychINFO, and 203 from CCTR. Two systematic reviews and 15 randomized trials (4 on sleep, 5 on mood, 6 on both) met eligibility criteria. However, no studies specifically assessed the efficacy of cannabis on psychological symptoms as primary outcomes in cancer patients. The studies varied widely in terms of interventions, control, duration, and outcome measures. Six of 15 RCTs suggested benefits (five for sleep, one for mood). Conclusion: There is no high-quality evidence to recommend the use of cannabis as an intervention for psychological symptoms in patients with cancer until more high-quality research demonstrates benefit.