How cannabis and other drugs trigger widespread inflammation beyond the brain

This comprehensive review fundamentally reshapes our understanding of how substance use—including cannabinoids—affects the body beyond just the brain. Traditionally, addiction and substance use disorders have been viewed as primarily affecting the brain's reward systems; however, accumulating evidence demonstrates that addictive substances, including cannabinoids, trigger widespread immune and inflammatory responses across multiple organ systems including the gut, liver, lungs, skin, and systemic circulation. The research shows that various substances remodel how neurons, immune cells, and glial cells communicate with each other, creating persistent changes in both central (brain and spinal cord) and peripheral (body-wide) immune function.

The significance of this work lies in revealing shared cellular and molecular mechanisms of inflammation across different tissues, suggesting that substance exposure—whether opioids, psychostimulants, alcohol, nicotine, cannabinoids, or psychedelics—activates similar inflammatory pathways throughout the body. This neuroimmune remodeling has major implications for understanding long-term health consequences of substance use beyond addiction itself. For cannabis users specifically, this research highlights that cannabinoid exposure may trigger systemic inflammatory and immune changes that could affect gut health, organ function, and overall immune competence in ways previously underappreciated.

Understanding these mechanisms opens new therapeutic possibilities and underscores the importance of considering whole-body effects when evaluating cannabis safety and efficacy. The emerging paradigm of "systemic neuroimmune crosstalk" suggests that addressing inflammation and immune dysregulation may be just as important as addressing brain-based reward pathways when treating substance use disorders and their health consequences.