A case is reported of a 37-year-old woman with a long-lasting anxiety disorder and a history of both alcohol benzodiazepine anxiolytics abuse. In the course of pharmacotherapy thianeptine was administered with an almost immediate symptom relieffollowing. However, shortly (in a few months' time) the patient's "demand" for the drug has increased to 30 pills per day. During the next 2 years the patient manifested distinct symptoms of thianeptine dependence, with all the consequences. Various causes of this unusual situation (so far never reported in the literature) are discussed, including both the patient's characteristics and properties of the drug.