Cannabis use, sleep and mood disturbances among persons with epilepsy – A clinical and polysomnography study from a Canadian tertiary care epilepsy center

Objective: Interest in anti-seizure properties of cannabinoids is increasing, with the rise in prevalence of recreational and medical cannabis use, especially across Canada. In a recent study on people with epilepsy (PWE), cannabis use showed a strong association with poor psychosocial health. Sleep and mood comorbidities are highly prevalent in epilepsy, and are common motivations for cannabis use. The primary objective of this study was to assess demographic, subjective and objectively assessed sleep quality and mood related differences among PWE who regularly use cannabis compared to those who do not.

Methods: Consecutive consenting patients with a confirmed epilepsy diagnosis, admitted to our Epilepsy Monitoring Unit, over a 3-year period (2019-2022) were enrolled. Detailed epilepsy-related data and self-reported sleep [Pittsburgh Sleep quality index (PSQI)], Epworth Sleepiness Scale (ESS)], mood [(Beck’s Depression Inventory (BDI) and Beck’s Anxiety inventory (BAI)] and cannabis use related data were collected. Overnight polysomnography (PSG) was conducted on the first night of admission, with simultaneous 18-channel video-EEG. Sleep (PSG) scoring followed American Academy of Sleep Medicine guidelines by a scorer blinded to clinical details.

Results: Among 51 patients with similar seizure control, 25 (13 F) reported cannabis use (mean age 36.3+14.8 years) and were significantly younger than 26 (18 F) non-users (mean age 48.3+15 years). Cannabis users had significantly better subjective sleep quality (mean PSQI scores 7.2+2.9 vs 10.2+5.2 respectively). Most patients endorsed sleepiness (Cannabis users with ESS scores greater than 10; 91.3 %, 77.3 % in non-users) and moderate to extreme depression (BDI) scores. No significant differences were observed in objective sleep parameters. BDI score significantly predicted PSQI and ESS scores on multiple logistic regression analysis.

Significance: Despite a significant age difference, self-reported sleep quality is better among PWE who report regular cannabis use compared to non-users. However, there is no significant difference in objective sleep quantity and quality from PSG between the two groups. Additionally, severity of depressive symptoms is a significant predictor of sleep quality and of excessive daytime sleepiness among PWE.