The use of cannabis to treat various medical conditions or to alleviate pain resulting from symptoms of disease states is increasingly common. Over the past four decades, cannabis in a wide variety of forms has risen to “folklore” status as a remedy for numerous ailments. However, the impact of cannabis use on “patient self-reported” outcomes, such as health-related quality of life (HRQoL), remains unclear.
To date, studies showing a positive impact on HRQoL involved subjects with pain symptoms.
Goldenberg and colleagues conducted a systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The investigators categorized studies based on design, targeted conditions, type of cannabis or cannabinoid used, and the method of drug delivery. The studies were scored based on quality and risk of bias—which eliminated some studies because of poor quality or insufficient data.
Meta-analyses of the remaining studies met our pre-defined selection criteria. Eleven studies were randomized controlled trials (RCTs; 2322 participants); the remaining studies were of cohort and cross-sectional design. Cannabinoid studies were primarily RCTs of higher design quality than studies of cannabis, which utilized smaller self-selected samples in observational studies. Although we did not uncover a significant association between cannabis and cannabinoids for medical conditions and HRQoL, some patients who used them to treat pain, multiple sclerosis and inflammatory bowel disorders reported small improvements in HRQoL, and at the same time, some HIV patients reported reduced HRQoL.
The relationship between HRQoL and the use of cannabis or cannabinoids for medical conditions remains inconclusive. Some patient populations report improvements whereas others report reductions in HRQoL. In order to inform users, practitioners and policymakers more clearly, future studies should adhere to stricter research quality guidelines and more clearly report patient outcomes.
Why Does This Matter?
The truth about the medicinal effects of cannabis for serious medical conditions is no small matter. The folklore and fiction surrounding cannabis as medicine has not stood up to scientific inquiry. Clearly the euphoric effects of THC have analgesic properties and will temporarily mediate pain via the brains reward center. But this is a different matter than mediation of neuropathic pain from diabetes, nerve damage of fibromyalgia or crippling inflammation from rheumatoid disease.
Yet as the investigators discovered, self-reported benefits from smoking marijuana confound the issues. We remain very optimistic that medicines from cannabis will be developed that bring relief and healing to those suffering from debilitating conditions. Certainly, smoking marijuana as part of palliative care during chemo or end of life care is widely accepted and practiced.