A comprehensive review published in The BMJ emphasizes caution regarding cannabis use, particularly in adolescence, early adulthood, and among individuals at risk for mental disorders. The review, conducted by Dr. Marco Salmi and colleagues from the University of Ottawa in Canada, examined a wide range of meta-analyses to assess the credibility and certainty of associations between cannabis, cannabinoids, and cannabis-based medicines, and their impact on human health.
The review included a total of 101 systematic reviews with meta-analyses of both observational studies and randomized controlled trials. The findings provide insights into the potential risks and benefits associated with cannabis use:
Adverse Events: Cannabis-based medicines were linked to increased adverse events related to the central nervous system, psychological effects, and vision in people with mixed medical conditions. These associations were graded with high certainty.
Psychiatric Effects: In the general population, cannabis was associated with worsening positive psychotic symptoms and overall psychiatric symptoms, both graded with high certainty. It also had negative effects on cognition.
Epilepsy: Cannabidiol, a compound found in cannabis, reduced seizures and improved quality of life in people with epilepsy but came with side effects.
Cancer Patients: Cannabinoids improved sleep disruption in cancer patients but carried a risk of gastrointestinal adverse events.
Pregnant Women/Neonatal Outcomes: Harmful effects were observed in pregnant women and neonatal outcomes when cannabis was used.
Healthy Individuals: In healthy individuals, cannabinoids improved pain symptoms but impaired cognition.
Multiple Sclerosis, Chronic Pain, Inflammatory Bowel Disease, Palliative Medicine: Cannabis-based medicines were effective in individuals with multiple sclerosis, chronic pain, inflammatory bowel disease, and palliative care, but they also carried a risk of adverse events.
This review underscores the need for caution when considering cannabis use, particularly for individuals who are vulnerable to mental health issues. It highlights the complex interplay between cannabis and various health outcomes, with both potential benefits and risks. Public health initiatives should aim to provide clear information about the potential consequences of cannabis use to help individuals make informed decisions about their health.
