Impacts of medical and non-medical cannabis on the health of older adults: Findings from a scoping review of the literature

Abstract

Background Cannabis legalization has enabled increased consumption in older adults. Age-related mental, physical, and physiological changes may lead to differences in effects of cannabis in older adults compared to younger individuals. Objective To perform a scoping review to map the evidence regarding the health effects of cannabis use for medical and non-medical purposes in older adults. Methods Electronic databases (MEDLINE, Embase, PsycINFO, Cochrane Library) were searched for systematic reviews (SRs), randomized controlled trials (RCTs) and non-randomized/observational studies (NRSs) assessing the health effects and associations of cannabis use (medical or non-medical) in adults ≥ 50 years of age. Included studies met age-related inclusion criteria or involved a priori identified health conditions common among older adults. Records were screened using a liberal accelerated approach and data charting was performed independently by two reviewers. Descriptive summaries, structured tables, effect direction plots and bubble plots were used to synthesize study findings. Findings From 31,393 citations, 133 publications describing 134 unique studies (26 SRs, 36 RCTs, 72 NRSs) were included. Medical cannabis had inconsistent therapeutic effects in specific patient conditions (e.g., end-stage cancer, dementia), with a number of studies suggesting possible benefits while others found no benefit. For medical cannabis, harmful associations outnumbered beneficial, and RCTs reported more negative effects than NRSs. Cannabis use was associated with greater frequencies of depression, anxiety, cognitive impairment, substance use and problematic substance use, accidents/injuries, and acute healthcare use. Studies often were small, did not consistently assess harms, and did not adjust for confounding. Discussion The effects of medical cannabis are inconsistent within specific patient conditions. For older adults, generally, the available evidence suggests cannabis use may be associated with greater frequencies of mental health issues, substance use, and acute healthcare use, and the benefit-to-risk ratio is unclear. Studies with a balanced assessment of benefits and harms may guide appropriate public health messaging to balance the marketing pressures of cannabis to older adults.

Marijuana use among community‐dwelling older adults: A population‐based study

“…One‐third of participants with recent marijuana use had been prescribed a psychotropic medication, compared to a quarter of those with no history or no recent use of marijuana. These findings are consistent with prior studies linking marijuana use to mental health problems in older adults 15,21,43 . Although some individuals with mood disorders may be attempting to self‐medicate their symptoms with marijuana, there is evidence from longitudinal studies of younger people that marijuana use, especially frequent and/or heavy use, increases the likelihood of these symptoms 44–48 .…”

“…These findings are consistent with prior studies linking marijuana use to mental health problems in older adults. 15,21,43 Although some individuals with mood disorders may be attempting to self-medicate their symptoms with marijuana, there is evidence from longitudinal studies of younger people that marijuana use, especially frequent and/or heavy use, increases the likelihood of these symptoms. [44][45][46][47][48] Similarly, reductions in marijuana use may result in decreased depression scores 49,50 although this work needs to be replicated in older adults.…”

“…In the absence of RCTs, the literature on marijuana use in older adults mainly consists of observational studies. More adverse effects of marijuana use are reported in RCTs than in observational studies 15 . For example, older patients dosed with delta‐9‐tetrahydrocannabinol (THC) in a clinical trial were more likely to report dizziness or lightheadedness and thinking or perception disorder compared to patients on placebo or THC combined with cannabidiol (CBD) 14 .…”

Cannabis Use in Older Adults

“…Information regarding cannabis is frequently received from online, television, and radio sources and is often not evidence-based or accurately identifying the effects of cannabis use. Marketing of cannabis tends to exaggerate the purported medical and wellness benefits, while minimizing any harmful effects (Wolfe et al, 2023).…”

“…Research studies have not fully connected the widespread benefits as marketed to cannabis consumers, but positive effects have been confirmed in certain cases. Cannabis use has been found to benefit individuals with conditions of neuropathic pain; chemotherapy-induced nausea and vomiting; spasticity (from multiple sclerosis and spinal cord injury); palliative pain; and end-of-life pain (Wolfe et al, 2023). There is also a positive correlation with reduced risk of head/neck and prostate cancers with cannabis consumption.…”