Although the opioid epidemic may command more national headlines, the past two decades have seen a revolution in cannabis policy driven largely by the public and by business interests. As a result, the population of cannabis users nationwide-especially of heavy users-has grown yearly. Although less visible than patients admitted to the emergency department for opioid-related overdose or to treatment for opioid use disorder, an estimated 4.5-7 million individuals in the United States are thought to meet criteria for cannabis use disorder in a given year. This article focuses on the developmental pathways of cannabis use disorder, the epidemiology of cannabis use among adolescents and adults in the context of rapidly changing state laws, and evidence-based treatment for the general psychiatrist. The authors provide an overview of pharmacological and psychosocial behavioral treatments for patients with the disorder while emphasizing aspects of clinical management unique to this patient population.