August 9, 2026

@michaelokun

One of the discussions that really resonated with me this week was this carefully conducted randomized controlled trial showing that a cannabis-based oil containing CBD and a low dose of THC did not improve pain or other non-motor symptoms in Parkinson's disease compared with placebo. Does this mean the story of cannabinoids in Parkinson's disease is over? I don't think so. The brain, including the basal ganglia, is rich in cannabinoid receptors, and pain, sleep, anxiety, and other non-motor symptoms remain biologically plausible treatment targets. This study raises important questions rather than closing the book. Was the THC dose too low? Did the specific CBD:THC formulation matter? Were the participants too heterogeneous? Could timing with meals, pharmacokinetics, or identifying the right symptom subgroups make a difference? The investigators themselves point to these possibilities and appropriately call for future studies using different formulations and higher cannabinoid doses while maintaining safety. Negative trials move science forward. Sometimes they tell us a treatment does not work, and other times they remind us that we may not yet know how to use the right therapy in the right patient at the right dose. https://movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.70449