Nearly all patients prescribed medical cannabis for mental health conditions reported symptom improvement, according to the largest multi-clinic patient survey of its kind in the UK.
The survey, conducted across Mamedica, Alternaleaf, CB1 Medical and Curaleaf in April 2026, gathered responses from 6,282 patients. Of the 5,128 patients prescribed treatment for anxiety, depression or post-traumatic stress disorder (PTSD), 97.6% reported improvement in symptoms, whilst 92.3% reported better sleep, and 93.5% said their ability to function day to day had improved.
Most strikingly, 88.3% of respondents said medical cannabis was the most effective treatment they had tried for their condition, with 90.7% reporting it was more effective than previous treatments.
The findings come as UK mental health services remain under sustained pressure. More than four million people were in contact with NHS mental health, learning disability and autism services in 2024/25. Published estimates from the STAR*D trial suggest that around 30% of patients with major depression do not achieve adequate symptom relief after multiple treatment attempts. A 2024 report found that nearly one in four adults living in the UK are prescribed antidepressants.
Additional UK polling analysed alongside the survey findings found that more than one in five UK adults – approximately 11.5 million people – said they had struggled to find an effective remedy to manage a mental health condition in the past five years. The issue was particularly pronounced among younger adults, with 31% of 18-24 year-olds and 30% of 25-34 year-olds reporting difficulty finding effective treatment.
Jon Robson, chief executive of Mamedica, said the data showed “consistent improvements across symptoms, sleep and daily functioning, particularly among patients who have already undergone multiple treatment pathways without adequate relief”.
“The results are resounding and speak to a clear trend of efficacy across the industry that needs to be acknowledged beyond the realms of patient and clinician circles,” Robson said.
The clinics stressed that the cross-sectional, voluntary survey findings should not be interpreted as definitive evidence of efficacy for anxiety, depression or PTSD more broadly; the results add to a growing body of real-world evidence – including the UK Medical Cannabis Registry and Project Twenty21 – supporting considered prescribing in patients who have not benefited from first-line interventions.
Dr Imogen Kretzschmar, consultant psychiatrist, said the findings reflected patterns seen in clinical practice. “Improvements in sleep, anxiety and functional capacity are clinically interdependent, and when they occur together, they represent meaningful change for patients,” Kretzschmar said. “At the same time, these treatments require careful patient selection, risk assessment and ongoing monitoring, and are not appropriate for all individuals.”
In the UK, only doctors listed on the General Medical Council (GMC) Specialist Register can prescribe medical cannabis, and only where conventional treatments have failed or proved inappropriate. Prescribing decisions are made through multidisciplinary team review, with ongoing monitoring and follow-up. Clinics are regulated by the Care Quality Commission, and the treatments are pharmaceutical-grade, prescription-only medicines, distinct from illicit cannabis.
Ross Dean, a Mamedica patient being treated for anxiety and depression, said he had been on “all different prescription pills” since the age of 17 and would also self-medicate with strong painkillers and benzodiazepines.
“But since a neighbour recommended trying medical cannabis, I have seen a big improvement on my condition and I’m eating more meals a day and also leaving the house to go on long walks with my dog,” Dean said. “From experience of being on prescription pills and the horrible side effects that come with it, I find that using medical cannabis has zero negative side effects for me and if I choose to have a break for a few days or longer it doesn’t bring me any withdrawal side effects like prescription pills would do.”
Kiri, 38, a CB1 Medical patient with anxiety and Ehlers-Danlos syndrome, said medical cannabis had “helped quieten the anxiety, improve my sleep, and given me more confidence to live normally again”.
“I’d tried different treatments over the years, but many left me feeling numb or unlike myself,” she said. “I finally feel like I have a treatment plan that sees me as a whole person, not just a list of symptoms.”
Chris, 48, a Curaleaf patient with complex PTSD (C-PTSD) and chronic pain, said he had tried antidepressants and talking therapy for years. “The antidepressants left me feeling detached and numb, like a shell, like I wasn’t really there, and the therapy alone often sent me into a spiral rather than out of one,” he said. “For the first time, I had a treatment that gave me consistency and stability. The oils gave me a sense of calm I hadn’t ever felt. My wife and children have the person who they truly deserved and the real me, not the person trapped behind a mask.”
This is the first time multiple UK medical cannabis clinics have pooled patient experience data at this scale, with the consortium intending to repeat the survey annually to build a recurring benchmark for patient-reported outcomes across the sector.
Based on their clinical experience and the outcomes reported by patients, the clinics are calling for increased government and research council funding for randomised controlled trials examining cannabis-based medicinal products in treatment-resistant anxiety, depression and PTSD.
Dr Simon Erridge, director of research at Curaleaf Clinic, said the outcomes built on data published by the UK Medical Cannabis Registry. “The findings support calls for further randomised controlled trials to determine whether medical cannabis could be considered earlier in the treatment pathway for these patients and/or within the NHS.”
Mike Barnes, chair of the Medical Cannabis Clinicians Society (MCCS), said the data is “too substantial to set aside”.
“These findings reflect what clinicians see in practice: that for carefully selected patients with genuine unmet need, medical cannabis can form a meaningful part of a broader treatment plan. Data at this scale, showing improvement across symptoms, sleep and daily functioning, do not prove causation, but they are too substantial to set aside. We need better trials, and we support government funding for rigorous independent research.”
Nabila Chaudri, medical director and pharmacist at Alternaleaf Clinic, said the results highlighted the potential impact on patients’ day-to-day lives. “For patients living with conditions such as anxiety, depression and PTSD – many of whom come to our clinic after finding limited success with other treatment options – this can make a real difference,” Chaudri said.
Patients widely reported medical cannabis as well-tolerated, and a significant proportion reduced or stopped other medications following treatment. The clinics are urging continued recognition of the role played by the UK Medical Cannabis Registry and other real-world data sources in supporting pharmacovigilance and long-term outcomes research, alongside a more transparent, sector-wide approach to publishing patient outcomes.
