What topics does this cannabis study cover?

This study covers research on: Mental Health, Anxiety, Sleep.

Where was this research published?

Published in Journal of affective disorders on April 15, 2026.

Mental Health Anxiety Sleep

Medical cannabis shows promise for depression in major UK study

UK Medical Cannabis Registry: A two-year case series of clinical outcomes in depression.

Journal of affective disorders • April 15, 2026 • Moderately Relevant

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AI Summary

A landmark UK Medical Cannabis Registry study examined how cannabis-based medicinal products (CBMPs) affect patients with depression over two years. Among 698 patients tracked longitudinally, researchers measured improvements in depression severity using the PHQ-9 scale, anxiety levels (GAD-7), sleep quality, and overall health-related quality of life at regular intervals. All key outcome measures showed statistically and clinically significant improvements at every follow-up point, with the most dramatic improvements occurring within the first 3 months of treatment initiation.

The study revealed important comorbidity patterns: approximately half of the patients experienced severe anxiety alongside their depression, and these two conditions were strongly correlated (r = 0.67). Notably, the treatment showed an excellent safety profile, with only 9.03% of patients reporting adverse events, and of those who did, 87.26% experienced only mild to moderate side effects. These findings suggest that cannabis-based medicinal products may offer a promising treatment option for depression, particularly for patients experiencing concurrent anxiety and sleep disturbances.

While the authors acknowledge that observational data cannot prove causation, these real-world results provide important evidence supporting the need for rigorous controlled clinical trials. The substantial improvements in quality of life and mental health outcomes, combined with favorable safety data, suggest CBMPs warrant further investigation as a potential therapeutic approach for depression—a condition affecting millions globally with limited effective treatment options for some patients.

📄 Original Abstract

Whilst preclinical evidence details the effects of cannabinoids on mood regulation, there is a paucity of clinical evidence on the use of cannabis-based medicinal products (CBMPs) in individuals with depression. This study aims to evaluate longitudinal changes in patient-reported outcome measures (PROMs) and the incidence of adverse events over 24 months in patients treated with CBMPs for depression. Patient data from the UK Medical Cannabis Registry were used for analysis. PROMs, including the Patient Health Questionnaire-9 (PHQ-9), Generalised Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), EuroQol 5-Dimension 5-Level (EQ-5D-5L), and Patient Global Impression of Change (PGIC), were measured at baseline, 1, 3, 6, 12, 18, and 24 months. Adverse events (AEs) were also recorded. P < 0.050 was considered statistically significant. Of the 34,563 patients in the UK Medical Cannabis Registry on January 6th 2025, 698 (2.02 %) patients were included in the analysis. Improvements were observed across the PHQ-9. GAD-7, SQS, and EQ-5D-5L index value at all time points compared to baseline (p < 0.001). At baseline, half of the patients reported severe anxiety (GAD-7 ≥ 15: 50.86 %, n = 355), which was correlated with depression severity (PHQ-9; r = 0.67, p < 0.001). Sixty-three patients (9.03 %) reported at least one AE during treatment, of which 87.26 % (n = 411) were mild or moderate. Initiation of CBMPs was associated with statistically and clinically significant improvements in depression, anxiety, sleep quality, and health-related quality of life among patients. Improvements were most prominent in the first 3 months. Limitations of the study mean that no causal relationship can be ascertained. The positive findings from this and other observational data support future evaluation of CBMPs for the treatment of depression to establish their efficacy.

Paper Type

📄 Research

Publication

Journal: Journal of affective disorders
Published: April 15, 2026
PMID: 41506388
DOI: 10.1016/j.jad.2025.121130

Authors (17)

Elizabeth Lillywhite Medical Cannabis Research Group, Imperial College London, London, UK.
Simon Erridge Medical Cannabis Research Group, Imperial College London, London, UK; Curaleaf Clinic, London, UK. Electronic address: simon.erridge12@imperial.ac.uk.
Evonne Clarke Curaleaf Clinic, London, UK.
Katy McLachlan Curaleaf Clinic, London, UK.
Ross Coomber Curaleaf Clinic, London, UK; St. George's Hospital NHS Trust, London, UK.
+12 more authors