Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

Posttraumatic stress disorder (PTSD) affects over 70% of veterans receiving mental health benefits from Veterans Affairs Canada, with many turning to cannabis for medical purposes (CMP) for symptom relief when conventional treatments fall short. Dysregulation in the endocannabinoid system, including reduced anandamide and elevated CB1 receptor expression, suggests that cannabis, as a partial CB1/CB2 receptor agonist, may hold therapeutic potential by addressing these deficiencies. Sleep disturbances, a hallmark of PTSD, often prompt veterans to use CMP. PTSD-related autonomic arousal and nightmares disrupt sleep initiation, maintenance, and quality. Veterans frequently exhibit abnormalities in slow-wave sleep and elevated rapid eye movement pressure, although these effects vary and may diminish over time. Cannabis's effects on sleep depend on its composition, with cannabidiol showing promise for alleviating sleep problems, while prolonged THC use may impair sleep quality. Understanding these differential effects is critical to evaluate CMP's potential role in supporting sleep among trauma-exposed individuals. This study will examine how CMP use relates to sleep and mental health in veterans with PTSD over time. Objectives include: (1) track longitudinal sleep and mental health changes in veterans with PTSD who are using CMP and those not; (2) investigate how CMP use patterns relate to sleep and mental health, (3) identify characteristics of veterans with PTSD who report benefits from using CMP as a sleep aid. This study includes a national survey collecting longitudinal data on cannabis use, sleep health, and related factors like chronic pain and mental health. A subset of participants will undergo physiological sleep monitoring, including home-based electroencephalography and electrocardiography. Insights will inform randomized trials, identifying predictors of therapeutic response and mechanisms linking cannabis use to improved sleep and well-being in PTSD.