Alcohol use disorder, one of the most prevalent mental disorders worldwide, was reclassified in the DSM-5. Grant and colleagues used the National Comorbidity Survey Replication to present the epidemiology of DSM-5 alcohol use disorder. Twelve-month and lifetime prevalences of alcohol use disorder were 13.9% and 29.1%, respectively. Only 19.8% of respondents with lifetime alcohol use disorder were ever treated. Significant associations were found between alcohol use disorder and other mental disorders, especially bipolar, major depressive, and personality disorders.