A preliminary investigation of sex differences in cognitive and fMRI changes following 28 days of cannabis abstinence.
C. Meza, C. Stefan, W. Staines, A. Feinstein
Multiple sclerosis and related disorders July 17, 2024 DOI: 10.1016/j.msard.2024.105759 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational longitudinal study with repeated measures Peer reviewed |
|---|---|
| Sample size | 19 |
| Population | Adults with multiple sclerosis who are long-term, frequent cannabis users (8 males, 11 females) |
| Duration | 28 days of cannabis abstinence; assessments at baseline and day 28 |
| Measures | Selective Reminding Test (SRT), n-back, Symbol Digit Modalities Test (SDMT), resting-state default mode network fMRI, task-based fMRI |
| Topics | Cannabis |
| Key findings | After 28 days of cannabis abstinence, women performed better than men on the Selective Reminding Test (p = 0.04, large effect size η² = 0.286), while no significant sex-by-time interaction appeared on the SDMT or n-back task. The authors conclude that cannabis masked sex-based cognitive differences and that women showed greater resting-state default mode network activation at day 28 alongside comparable or better cognitive performance. |
Abstract
Background: Previous studies have investigated the influence of cannabis on cognition among people with MS (pwMS), yet the influence of sex in the context of cannabis use remains unexplored. We aim to fill this gap by investigating cannabis-sex related differences in verbal learning, memory and processing speed in association with fMRI (resting state, and task-based) metrics.
Method: Our sample consisted of 19 long-term, frequent cannabis users (8 males, 11 females). Assessments were conducted at baseline and after 28 days of cannabis abstinence. The tests included measures of verbal memory (Selective Reminding Test (SRT)), working memory (n-back), information processing speed (Symbol Digit Modalities Test (SDMT)) and the resting state DMN. To evaluate the effects of cannabis abstinence, we performed a group x time interaction analysis using repeated measures ANCOVA. This analysis controlled for several covariates, including the level of disability (EDSS), baseline cannabis THC metabolite levels, and cannabis withdrawal symptoms. By controlling for these variables, we aimed to isolate the impact of cannabis abstinence on cognitive performance over time. Statistical significance was set at p < 0.05.
Results: There were no baseline cognitive differences between the sexes. After 28 days of cannabis abstinence, females performed better on the Selective Reminding Test (SRT) (p = 0.04), with a large effect size (η² = 0.286). The mean correct response improved over time for females, but there was no statistically significant group x time interaction on the Symbol Digit Modalities Test (SDMT) and the n-back task. Resting state default mode network data showed overall increased activation in females relative to males at day 28, which meshed with lower brain activation during task-based fMRI paradigms.
Conclusion: Cannabis negated sex-based cognitive differences. Functional MRI task-based paradigms revealed less cerebral activation in females compared to males, which was associated with comparable or better cognitive performance in females, particularly after cannabis abstinence.
Citations in the library
Cites 3
- Coming off cannabis: a cognitive and magnetic resonance imaging study in patients with multiple sclerosis Brain July 3, 2019
- An evidence based review of acute and long-term effects of cannabis use on executive cognitive functions. Journal of Addiction Medicine March 2011
- Cannabinoid receptor localization in brain. Proceedings of the National Academy of Sciences March 1990