Australians’ use of medicinal cannabis has skyrocketed in recent years, with about 700,000 people turning to it for health reasons over the past year. Sales have quadrupled since 2022. However, most products available lack registration from the Therapeutic Goods Administration, meaning they undergo limited testing. Questions persist about their safety and efficacy.
Largest Review Examines Mental Health Applications
The most extensive analysis to date, covering 54 randomized controlled trials from 1980 to 2025, evaluates medicinal cannabis for mental health conditions and substance use disorders. These include top prescription reasons like anxiety, sleep issues, post-traumatic stress disorder (PTSD), insomnia, depression, and attention deficit hyperactivity disorder (ADHD).
Results show minimal evidence that medicinal cannabis outperforms placebos for these conditions. Cannabidiol (CBD) featured in most trials, followed by tetrahydrocannabinol (THC) and THC-CBD combinations. CBD remains non-intoxicating and generally safe, while THC can cause short-term paranoia and long-term dependency risks.
Key Findings on Effectiveness
Cannabis medicines proved no better than placebos for psychotic disorders like schizophrenia, anxiety, PTSD, anorexia, or opioid use disorder. Positive signals emerged for reducing cannabis consumption in those with cannabis use disorder, often via oral CBD-THC oils that curb cravings. Switching from high-THC smoked cannabis to these formulations may lower risks like lung damage.
Safety Profile and Real-World Gaps
Trials linked cannabis medicines to mild side effects including nausea, dry mouth, and fatigue. Serious events like psychotic episodes occurred at rates similar to placebos. Yet, studies averaged just five weeks, overlooking long-term harms from regular use.
One recent analysis indicates about 25% of medicinal cannabis users develop dependency, matching recreational rates. Many Australian products contain high THC levels, which heighten mental health risks, especially for youth. Trial formulations skewed toward low-THC, CBD-heavy options, diverging from common real-world choices.
Study Limitations
Promising results for tics, Tourette’s syndrome, insomnia, and autism relied on few, low-quality trials. Intoxicating effects often unblinded participants, introducing bias. Some studies disclosed conflicts of interest.
Implications for Future Use and Regulation
Prior reviews align with these conclusions, highlighting scant proof for mental health benefits amid short-term, CBD-focused data versus prolonged, high-THC real-world patterns. Expanded research, especially for underserved conditions and long-term monitoring, is essential.
As regulators review prescribing practices, these insights could shape policies to prevent harm and promote proven alternatives. Patients experiencing benefits should consult doctors regularly and explore evidence-based options.
