“Background: 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.

Methods: 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.

Results: 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 85 % (n = 411) were mild or moderate.

Discussion: 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.

Conclusion: The positive findings from this and other observational data support future evaluation of CBMPs for the treatment of depression to establish their efficacy.”

https://pubmed.ncbi.nlm.nih.gov/41506388

“This UK Medical Cannabis Registry study of patients with treatment-resistant depression prescribed CBMPs demonstrated sustained and clinically meaningful improvements in depression, anxiety, health-related quality of life, and sleep quality over 24 months. Improvements were most pronounced within the first three months and were sustained thereafter. Adverse events were infrequent and predominantly mild to moderate.”

https://www.sciencedirect.com/science/article/pii/S0165032725025728?via%3Dihub