Introduction: Legalization of medical cannabis (MC) continues to expand across the U.S., with increasing numbers of patients using cannabis to treat a variety of medical symptoms. Despite increased MC use, few studies have examined the longitudinal impact of MC treatment on brain function and cognitive performance.

Methods: As part of a larger, longitudinal, observational study assessing the impact of MC use, adults with various medical and psychiatric conditions (e.g., pain, anxiety, mood disorders) were recruited into two groups: 1) patients planning to initiate MC use after baseline; and 2) patients with similar conditions who planned to continue treatment-as-usual (TAU) without MC. A subset of patients completed neuroimaging procedures including functional magnetic resonance imaging (fMRI) while completing the Multi-Source Interference Task (MSIT), a measure of cognitive interference processing that reliability and robustly activates the anterior cingulate cortex (ACC). Patients included in the current analyses (nMC=58, nTAU=23) completed imaging at baseline and at least one follow-up visit at 3, 6, and/or 12 months. Imaging analyses were conducted using fmriPrep and SPM 12 and assessed changes in ACC brain activation within each group (MC & TAU) at each visit. The statistical threshold for activation clusters was set at family-wise error corrected p≤.05 with k≥15 contiguous voxels. Linear mixed model (LMM) analyses assessed task performance differences between the groups over time.

Dr. Mary Kathryn (Kate) Dahlgren is an assistant neuroscientist in the Cognitive and Clinical Neuroimaging Core (CCNC) and the Marijuana Investigations for Neuroscientific Discovery (MIND) program, both led by Dr. Staci Gruber. Her work focuses on the impact of recreational and medical cannabis use on cognition, clinical state, neural activation, and brain structure. In addition, she has recently published several scientific papers as part of the Women’s Health Initiative at MIND (WHIM), the first cannabis research program in the nation focused on addressing sexual health, reproductive health, and disorders that disproportionately affect women as well as some transgender and non-binary individuals. Dr. Dahlgren is particularly interested in using advanced statistical modelling to identify predictors of treatment response.