Could a daily cannabinoid pill shield Athletes' brains from concussion?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Healthy male adults between 19-35 years of age that compete in contact sport athletics. * Participants with no known cerebrovascular or cardiovascular complications. * Participants will not be habitual recreational users of cannabis (i.e., \<1 day/week) or tobacco users. * Participants that agree not use any other cannabis or tobacco products while enrolled in the study. * Participants willing to provide a list of any prescription medications they are taking. * Ability to maintain commitment to all proposed biopsychological and health questionnaires, and neuro-physiological, physiological, perceptual-cognitive, and functional motor skills laboratory tests. * Participants who are capable of giving signed informed consent. Exclusion Criteria: * Female. * Must not travel to the USA during study period; USA laws do not permit cross border with cannabis products. * Use of cannabis-based therapy within 2 months (participants who have previously used a cannabis based therapy may be included if they have a 2-month period without use of cannabis-based therapy prior to enrollment in the study). * Participants with any level of cannabis in their blood samples when sampled at the commencement of the study will be excluded. * Participants that are being medically supervised for anxiety, depression, Post Traumatic Stress Disorder (PTSD), mood disorder, psychotic disorders or any cerebrovascular and cardiovascular complications. * Participants who are taking prescription medications such as psychotropic medications with serotonergic activity, including Selective Serotonin Reuptake Inhibitors (i.e. Fluoxetine), Tricyclic Antidepressants (i.e. Elavil, Nortriptyline) and Atypical Neuroleptics (i.e. Risperidone, Seroquel). * Initiation or dosage change of oral or injected steroids within 3 months. * Allergy or known intolerance to any of the compounds within the study preparation. * Unable to maintain commitment to all proposed biopsychological and health questionnaires, and neuro-physiological, physiological, and functional motor skills laboratory tests. * Inability of study participants to attend assessments on a regular basis at the pre-determined times, or failure to take the drug daily. * Clinically significant cardiac, renal or hepatic disease (as assessed by the site investigator). * If they already have a concussion at the time of starting the study.