Within a 2-year period from November 1, 1998, to November 30, 2000, all patients with alcoholism who were admitted to an inpatient alcohol withdrawal program at the Department of Psychiatry, University Hospital of Hamburg, and Northern Hospital of Hamburg, Hamburg, Germany, were informed about the study during an obligatory weekly information group. This action reached 782 patients with alcoholism; 196 of them were willing to be informed thoroughly about the details of the study. These patients were screened and given a structured interview for inclusion in the study (F.K., R.H.). Criteria for inclusion were as follows: (1) at least 5 DSM-IV criteria of alcohol dependence, (2) age between 18 and 65 years, (3) body weight of 60 to 90 kg, (4) complete abstinence for 12 to 15 days, (5) free of any withdrawal symptoms, and (6) drug screening test results negative for benzodiazepines, cannabinoids, barbiturates, opiates, cocaine, and amphetamines. Criteria for exclusion were as follows: (1) a current DSM-IV diagnosis of dependence or abuse on other substances except nicotine assessed by the Structured Clinical Interview for DSM-IV, (2) a current mental or psychiatric impairment or disease that required psychotropic medication or inpatient treatment on a psychiatric ward, (3) a history of opioid or cocaine abuse, (4) a history of psychosis, (5) current use of any psychotropic medication,(6) evidence of severe neurologic or physical disorders (eg, cerebral, renal, thyroid, or cardiac disease), (7) a history of cirrhosis or laboratory evidence of significant hepatocellular injury, (8) homelessness, and (9) pregnancy, nursing, or refusal to use a reliable method of birth control in women.