WHY IT MATTERS: Patients managing anxiety or depression who also use cannabis should discuss this openly with their prescribing physician, because the direction of that relationship matters significantly for how both conditions are treated. CLINICAL OVERVIEW: Research consistently shows a bidirectional relationship between cannabis use and mood disorders such as anxiety and depression, meaning cannabis can both precede the onset of these conditions and be used as a coping mechanism once they develop. The neurobiological underpinnings involve endocannabinoid system dysregulation, particularly in pathways governing stress response, emotional processing, and reward circuitry.