According to the Drug Abuse Warning Network (DAWN):
- During 2004, an estimated 192,690 patients in drug-related emergency department (ED) visits were diagnosed with co-occurring substance use and mental disorders.
- When ED visits involved co-occurring disorders, nearly as many patients were treated and released as were admitted to inpatient units (40.4% and 42.2% of visits, respectively).
- Cocaine and alcohol (in 31.8% and 29.3% of visits, respectively) were the drugs most frequently reported for ED visits with co-occurring diagnoses.