Medicinal Cannabis and its Treatment of Mental Illnesses

Recent reports highlight a significant increase in the prescribing of medicinal cannabis since its legalisation in 2018. Initially rising slowly and reaching around 10,000 recipients a month by mid-2022, the figures rose from 282,920 in 2023 to 659,293 in 2024. According to information gained via Freedom of Information requests, much of this is attributable to the issuing of prescriptions by private medicinal cannabis clinics. The latest figures suggest just ten private doctors issued more than half of all cannabis-based prescriptions in the UK.

Furthermore, emerging evidence reveals an alarming increase in the prescribing by private clinics of cannabis-based medicinal products (CBMPs) for the treatment of mental health and severe mental illness. There is limited evidence that CBMPs are effective at treating mental disorders, and we fully endorse the call for more and compelling research to be conducted.

Whilst we acknowledge the potential benefits for use of CBMPs in the treatment of a range of chronic physical pain when nothing else has worked, Adferiad does not support the use of cannabis for poor mental health or severe mental illness, and more research is urgently needed on CBMPs in all health settings. We fully support the Royal College of Psychiatrists’ position on CBMPs, which calls for greater high-quality research, clearer prescribing guidance, and a commitment to public education on the potential harms of cannabis use.

Adolescent Cannabis use and the risk of psychosis

There is a longstanding and growing body of evidence of a link between an increased risk of psychosis and cannabis use, particularly when involving cannabis with a high proportion of THC (and when used by young people).

This past February marked the publication of one of the largest longitudinal studies to examine cannabis use in adolescence and its association with the development of psychiatric disorders into young adulthood.

Utilising health data from over 460,000 individuals, the authors found that adolescent cannabis use was associated with an increased risk of multiple psychiatric disorders by early adulthood, particularly for psychotic and bipolar disorders.

Adferiad is committed to ensuring effective, compassionate support is available to individuals living with serious mental illnesses like schizophrenia and bipolar, we wholeheartedly support the authors’ suggestion that these results could inform the development of clinical and educational interventions for parents, adolescents, and clinicians.

Legalisation and Recreational Use

The use of cannabis comes with potentially severe health risks, and while there is limited clinical evidence on general health consequences, evidence exists which draws a link with increased risk of developing psychosis.

Adferiad does not support the legalisation of cannabis. In addition, while we firmly believe that its recreational use and the associated harms should be viewed as a public health issue, not a criminal justice one, decriminalisation must be supported by proper investment into prevention and treatment services.

As an organisation dedicated to providing meaningful support to people across Wales dealing with addiction and substance use problems, we advocate for well-funded services, harm reduction and help for people to cease use.