A systematic review and meta-analysis of 64 studies found medicinal cannabis improved health-related quality of life across chronic conditions, with small improvements in RCTs (d=0.30) and moderate-to-large improvements in observational studies (d=0.43-0.74) that increased with longer follow-up.
Patients with chronic conditions considering medicinal cannabis, clinicians evaluating patient-reported outcomes, and health policy researchers assessing cannabis program effectiveness.
Quality of life improved in both RCTs (d=0.30) and observational studies (d=0.43-0.74)
What the researchers found
RCTs showed small but statistically significant short-term HRQL improvements (Cohen's d=0.30, p=0.03). Observational studies showed improvements across all follow-up periods: short-term (d=0.43), medium-term, and long-term (d=0.74), all p<0.001. Only 61% of studies justified why they measured quality of life, and only 8% provided definitions.
Why it matters
Quality of life is ultimately what matters most to patients with chronic conditions. This meta-analysis provides the most comprehensive evidence to date that medicinal cannabis improves this patient-centered outcome, with effects that appear to grow rather than diminish over time.
The numbers in context
16,674 citations screened, 64 studies retained. 12 RCTs, 38 cohort, 13 case series. RCT short-term: d=0.30, p=0.03. Observational short-term: d=0.43, medium/long-term up to d=0.74, all p<0.001. EQ-5D-5L most commonly used measure. 81% used generic HRQL measures, 19% condition-specific.
How the study worked
Systematic review searching seven databases from January 2015 to April 2025. Sixty-four studies retained: 12 RCTs, 38 cohort studies, 13 case series, 1 non-randomized experimental. Meta-analyses conducted for short-term (2 weeks to 3 months), medium-term (3-12 months), and long-term (12+ months) outcomes. Risk of bias assessed for RCTs.
What this study cannot tell us
Observational studies showed larger effects than RCTs, possibly reflecting placebo effects, selection bias, or reporting bias. Only 8% of studies defined what they meant by quality of life. Heterogeneity across conditions and cannabis formulations. Long-term data largely from observational designs.
How to read the evidence
Moderate: large systematic review with meta-analysis across study designs, but limited by heterogeneity, RCT-observational effect gap, and poor HRQL reporting standards.
When this study was published
Published 2026. Studies from January 2015 to April 2025.
The bigger picture
The growing effect size over time (d=0.43 to 0.74) is notable. It suggests either cumulative benefits of sustained cannabis use, dose optimization over time, or selection bias as dissatisfied patients discontinue. The RCT-observational gap also warrants attention.
Questions still open
- Why do quality of life improvements appear to grow over time? How much of the effect is specific to cannabis versus general engagement in medical care? Which chronic conditions show the largest quality of life gains?
Common questions
Does medicinal cannabis improve quality of life?
Do the benefits of medicinal cannabis grow over time?
Read the original research
Health-related quality of life in patients receiving medicinal cannabis: systematic review and meta-analysis of primary research findings 2015-2025.
Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation, 35(3), 56
Citation
Tait, Margaret-Ann; Acret, Louise; Costa, Daniel S J; Campbell, Rachel; White, Kate; Rutherford, Claudia. (2026). Health-related quality of life in patients receiving medicinal cannabis: systematic review and meta-analysis of primary research findings 2015-2025.. Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation, 35(3), 56. https://doi.org/10.1007/s11136-026-04170-7
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