Investigating cannabis use and associated symptoms among university students with and without a history of concussion

ABSTRACT

Recently, there has been a growing interest in the use of cannabis after traumatic brain injury (TBI); however, little is known about the long-term effects of cannabis on milder injuries and post-concussive symptoms. Further, substance use often increases post-TBI and, thus, individuals who chronically use cannabis may unknowingly be exceeding safe or therapeutic doses. The current cross-sectional study explores the prevalence of cannabis use among university students with and without a history of concussion and examines the relationship between concussion and post-concussive symptoms as a function of cannabis use. Eighty-four undergraduates (n = 51 without a prior concussion; n = 33 with a prior concussion) completed a series of questionnaires, capturing their head injury history, current and past substance use, and post-concussive symptomatology. Results indicated that those with a history of concussion were more likely to use cannabis and had higher cannabis use severity scores compared to those without a previous concussion. Further, among cannabis users only, concussion severity demonstrated a significant positive association with post-concussive symptom (e.g., headaches, memory problems) severity (i.e., frequency, intensity, duration). Taken together, the long-term use of cannabis may be detrimental to individuals with a history of concussion, exacerbating, rather than mitigating, post-concussive symptoms.

KEYWORDS:

• Concussion
• Traumatic Brain Injury
• Cannabis
• Substance Use
• Post-Concussive Symptoms

Acknowledgements

CG received support from the Vanier Canada Graduate Scholarships (Vanier CGS) program during the preparation, data collection, analysis, and writing of this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, CG, upon reasonable request.

Notes

1 Sixteen participants did not report their total household income because they were unsure, while four indicated that the item is not applicable given their living situation.

2 Seven participants in the concussion group were unsure as to whether or not they lost consciousness at the time of injury.

3 When partial correlations were conducted controlling for alcohol consumption, results remained the same for total symptoms and all subscales of the PCSC, except for the fatigue subscale, which was also found to be significantly associated with injury severity in cannabis users only. Although similar analyses could not be conducted controlling for cigarette use among non-users (due to sample size limitations), the pattern of results remained largely unchanged among cannabis users when controlling for smoking.