Unique effects of chronic THC and CBD use in multiple sclerosis on cognitive and motor function, neuroimaging, and quality of life amid hazy cannabis legality

Multiple Sclerosis (MS) patients often endure a wide range of debilitating symptoms—cognitive and motor impairments, pain, fatigue, sleep disturbances, and emotional challenges like anxiety and depression—that significantly reduce their quality of life. As existing treatments are frequently inadequate, many MS patients turn to alternative therapies, particularly cannabis and its two primary constituents, Δ-9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD). THC is primarily responsible for intoxicating effects, while CBD is known for its medicinal properties, leading patients to self-select consumption ratios based on symptom relief needs. Despite increasing use, there is limited research on how chronic THC and CBD use impacts functional outcomes, quality of life, and brain structure and function specifically in MS patients. This dissertation aims to fill this gap by examining these relationships in detail.