Medical and recreational cannabis use often confer unique outcomes, not surprising given their distinct goals of use which dictate product choice. However, little is known about medical cannabis (MC) patients longitudinally, particularly older adults, regarding clinical and cognitive outcomes as well as cannabinoid exposure.

As part of the first longitudinal study of MC use, 46 MC patients aged 45+ completed assessments at baseline, prior to initiating MC treatment. All returned for at least one follow-up visit after 3, 6, and/or 12 months of treatment. Although patients self-select their MC products/treatment regimens, comprehensive data regarding frequency, dose, and cannabinoid content are collected in order to quantify actual cannabinoid exposure, including delta-9- tetrahydrocannabinol (d9-THC) and cannabidiol (CBD). Additionally, a pilot group of treatmentas-usual (TAU; n=10) patients who did not initiate MC use are also enrolled. All participants complete clinical (e.g., mood, anxiety, sleep, pain) and cognitive measures. The current, interim analyses examined changes between baseline and follow-up visits within each patient group.

Results revealed that over 3-12 months of treatment, MC patients demonstrated improvements across a number of clinical measures relative to baseline. For example, MC patients reported significantly improved mood, anxiety, sleep and pain over the course of 1 year of MC use, a pattern not observed in TAU patients. Overall, MC patients also exhibited stable or improved performance on measures of executive function and verbal learning/memory; TAU patients exhibited a similar pattern of performance. Interestingly and perhaps importantly, MC patients reported significantly higher CBD exposure than d9-THC exposure at all visits.

Findings suggest that MC treatment has a significant therapeutic effect for at least some older adults, underscoring the potential promise of cannabinoid-based treatments. Despite previous findings of cognitive decrements among recreational users, older adults using cannabis for medical purposes did not exhibit poorer performance over time, and in some cases demonstrated cognitive improvement. Additional work should assess which product profiles and types/dose/routes of administration are best for specific conditions in order to identify promising candidates for future clinical trials.