Higher Risk, Higher Reward? Self-Reported Effects of Real-World Cannabis Use in Parkinson's Disease

Abstract

Background: Despite limited evidence, people with Parkinson's disease (PD) use cannabis for therapeutic purposes. Given barriers to performing randomized trials, exploring real-world experiences with cannabis in PD is valuable.

Objective: Investigate the frequency and magnitude of symptomatic effects reported with cannabis use in PD.

Methods: An anonymous, 15-question, web-based survey was deployed on Fox Insight. Cannabis product types were defined (by relative tetrahydrocannabinol [THC] and cannabidiol [CBD] content) and respondents were asked to reference product labels. Questions focused on use patterns and subjective effects on 36 predefined symptoms (rated -2-markedly worse to +2-markedly better).

Results: 1,881 people with PD responded (58.5% men; mean age 66.5; 50.5% <3 years of PD). 73.0% of respondents reported medicinal use, though 30.8% did not inform their doctor. 86.7% knew their type of cannabis product: 54.6% took higher CBD, 30.2% higher THC, and 15.2% took similar amounts of THC and CBD products. Most common use was oral administration, once daily, for less than six months. Frequent improvements were reported for pain, anxiety, agitation, and sleep (>50% of respondents, mean magnitude 1.28-1.51). Dry mouth, dizziness, and cognitive changes were common adverse effects (20.9%-30.8%, mean -1.13 to -1.21). Higher THC users reported more frequent improvements in depression, anxiety, and tremor, and more frequent worsening in dry mouth and bradykinesia than other product types.

Conclusions: Respondents with PD reported using more CBD products, via oral administration, with mild subjective benefits primarily for sleep, pain, and mood. Higher THC products may be higher risk/higher reward for PD-related symptoms.

Keywords: 9‐Δ‐tetrahydrocannabinol; Parkinson's disease; cannabidiol; cannabis; therapy.

FIG. 1

Self‐reported effects of cannabis use on pre‐existing Parkinson's disease symptoms. Frequency of responses ranging from markedly worse to markedly better with cannabis use for each of 36 pre‐existing motor and non‐motor symptoms among survey respondents with Parkinson's disease (n = number of respondents reporting that symptom prior to cannabis use).

FIG. 2

Differences in the frequency of reported symptomatic improvement between different cannabis product types. Higher THC product users (blue bars) reported symptomatic improvement at greater frequencies than higher CBD product users (green bars), with similar THC/CBD product users (yellow bars) generally reporting intermediate frequencies of improvement.

FIG. 3

Differences in the frequency of reported symptomatic worsening between different cannabis product types. Higher THC product users (blue bars) reported symptomatic worsening at greater frequencies than higher CBD product users (green bars) except for worsening of nausea. Similar THC/CBD product users (yellow bars) reported intermediate frequencies of improvement overall.