An Observational, Longitudinal Study of Cognition in Medical Cannabis Patients over the Course of 12 Months of Treatment: Preliminary Results
Kelly A. Sagar, M. Dahlgren, A. Lambros, Rosemary T. Smith, Celine El-Abboud, S. Gruber
Journal of the International Neuropsychological Society July 1, 2021 DOI: 10.1017/s1355617721000114 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Longitudinal Peer reviewed |
|---|---|
| Population | Well-characterized medical cannabis patients initiating treatment |
| Intervention | Medical cannabis |
| Duration | 12-month treatment period with evaluations at baseline, 3, 6, and 12 months |
| Topics | Cannabis |
| Key findings | Medical cannabis patients showed significant improvements in executive function and clinical state (mood, anxiety, sleep) over 12 months, with verbal learning and memory remaining stable. Cognitive improvement was not correlated with cannabis use but was associated with clinical improvement, and clinical improvement was associated with higher CBD use. The authors conclude that medical cannabis patients may exhibit enhanced rather than impaired executive function over time. |
Abstract
Abstract
Objective: Cannabis use has increased dramatically across the country; however, few studies have assessed the long-term impact of medical cannabis (MC) use on cognition. Studies examining recreational cannabis users generally report cognitive decrements, particularly in those with adolescent onset. As MC patients differ from recreational consumers in motives for use, product selection, and age of onset, we assessed cognitive and clinical measures in well-characterized MC patients over 1 year. Based on previous findings, we hypothesized MC patients would not show decrements and might instead demonstrate improvements in executive function over time.
Method: As part of an ongoing study, MC patients completed a baseline visit prior to initiating MC and evaluations following 3, 6, and 12 months of treatment. At each visit, patients completed a neurocognitive battery assessing executive function, verbal learning/memory, and clinical scales assessing mood, anxiety, and sleep. Exposure to delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) was also quantified.
Results: Relative to baseline, MC patients demonstrated significant improvements on measures of executive function and clinical state over the course of 12 months; verbal learning/memory performance generally remained stable. Improved cognitive performance was not correlated with MC use; however, clinical improvement was associated with higher CBD use. Analyses suggest cognitive improvements were associated with clinical improvement.
Conclusions: Study results extend previous pilot findings, indicating that MC patients may exhibit enhanced rather than impaired executive function over time. Future studies should examine distinctions between recreational and MC use to identify potential mechanisms related to cognitive changes and the role of clinical improvement.