Abstract
This article presents the case of a 21-year-old female with a psychiatric history of depression and a history of chronic cannabis use who presented to the emergency department after overdosing on ondansetron and was urine test positive for marijuana (tetrahydrocannabinol (THC)). The patient was later transferred to a psychiatric unit for further evaluation, and after six days of hospitalization and cessation of marijuana, the patient demonstrated gradual improvement in her mental status examination and was deemed fit for discharge with follow-up instructions. This case illustrates the effect of cannabis use and cannabis use disorder on those with major depressive disorder (MDD), the component of cannabis that worsens the symptoms of depression, the role of the endocannabinoid system (ECS) in depression, and available treatments.