Title: White Matter Microstructure and Neuroinflammation in Adolescents with Psychotic-Like Experiences and Cannabis Use

Speaker: Nicole Ponto, MSc Student, Department of Medical Neuroscience, Dalhousie University

Date: Tuesday, April 15, 2025

Time: 11:30am - 12:30pm  

Location: Theatre C, Tupper Building

Description: Adolescence represents a critical neurodevelopmental period during which the brain undergoes extensive white matter maturation and synaptic reorganization. This period is also marked by increased vulnerability to environmental stressors, including cannabis use (CU), and the emergence of psychotic-like experiences (PLEs)—transient, subclinical phenomena that confers risk for future psychopathology. The current study investigates how CU and PLEs, independently and interactively, influence white matter integrity and neuroinflammatory processes in adolescents aged 15–16 years. Using advanced diffusion imaging techniques—including Diffusion Kurtosis Imaging (DKI) and Neurite Orientation Dispersion and Density Imaging (NODDI)—we assess microstructural integrity and markers of neuroinflammation within the superior longitudinal fasciculus, arcuate fasciculus, and anterior cingulate cortex. Drawing from a large community-based neuroimaging cohort (n = 123), we analyze both voxel-wise and tract-specific indices (MK, AK, RK, and ODI) to explore associations with CU frequency and PLE presence. Findings from this study offer insight into potential neuropathological mechanisms underlying the early expression of psychosis risk and highlight the utility of diffusion imaging in characterizing white matter changes in adolescence.