The Green Gold Rush: Profits vs. Public Health in Cannabis Liberalisation

A recent international review, published in Lancet Psychiatry, offers stark distinctions for nations navigating the complex landscape of cannabis policy reform. The study, spearheaded by Tom Freeman, a professor of psychology at the University of Bath, critically examined the dramatic shifts in global cannabis policies between 2000 and 2025, revealing divergent outcomes depending on the approach taken.

The core finding is unequivocal: commercialisation, where cannabis is sold in an open market akin to alcohol and tobacco, demonstrably drives up usage rates and an increase in mental health problems. Researchers observed this trend particularly in regions like the US and Canada, which adopted commercial markets. These areas saw not only more users but also a concerning rise in drug potency and a corresponding increase in hospital visits linked to psychosis and other mental health issues.

Conversely, countries that opted for decriminalisation – a path taken across parts of Europe, Africa, Oceania, and Asia – showed little evidence of a change in cannabis usage or psychiatric illness. The experience in Uruguay further underscores this distinction; despite legalising cannabis in 2013, the country's market remains strictly controlled by the state, with similar negligible impacts on usage and mental health recorded.

Professor Freeman attributes the negative outcomes in commercial markets to the inherent incentives of a for-profit industry dealing with an addictive product. He explains that such industries are motivated to sell cheaper, higher-potency products to maximise sales, thereby increasing use and the associated harms. This dynamic, he notes, mirrors the historical challenges of regulating the tobacco and alcohol industries, where increased sales have consistently led to greater public health burdens.

For policymakers in emerging economies, particularly across Africa where discussions around cannabis reform are nascent, these findings provide crucial insights. The review suggests that a blanket legalisation model, especially one that embraces full commercialisation, comes with significant societal costs in the form of increased public health expenditure and potential strain on mental health services. The report by the London Drugs Commission, commissioned by Mayor Sadiq Khan, further highlights the existing social justice dimensions of cannabis policy, noting that black people in the UK were five times more likely to be stopped and searched on suspicion of drug-related offences than white people. This adds another layer of complexity to reform efforts, stressing the need for equitable enforcement alongside policy shifts.

While the review acknowledges that it is “still very early days for any of these policy changes,” the unfolding patterns offer a clear cautionary tale. The evidence strongly suggests that regulatory caution, leaning towards decriminalisation or state-controlled models, presents a more responsible path for public health. This contrasts sharply with the unfettered commercialisation that prioritises profit over the documented risks of increased addiction and psychiatric illness.