We carried out a randomized double-blind study. This was a crossover design with two periods of 2 days each with one compound (either zopiclone or triazolam). The next 2 days of active trial periods the patients were allowed to choose the preferred coloured capsule of which both neither the patients nor the investigators knew about its real contents. 40 volunteers were chosen from our patients suffering from chronic alcoholism who just finished their detoxification. There were given coloured coded capsules, each of them containing either 0.25 mg triazolam or 3.75 mg zopiclone. The capsules should be swallowed when patients felt a desire for alcohol. The maximal dosage was 8 capsules per day (2.0 mg triazolam and 30 mg zopiclone). There was a significant difference of degrees of freedom and probability at a level of 0.0005 for the items of the Addiction Research Centre Inventory and a level of 0.0005 for the items of the 'profile of mood states'. None of the volunteers developed a special desire for zopiclone after withdrawal of the medication.