In this case report, the aim was to present a patient who is complaining of headache and started to venlafaxine and increased the dosage of this drug with a reason of decreasing its efficiency. A 35 year-old woman patient who applied to the doctor complaining of headache is started to 75 mg/day venlafaxine by psychiatrist, the dosage was increased to 225 mg/day by the same doctor and then the drug dosage was increased to 2100 mg/day by client self-decision. The venlafaxine dosage of patient, who was investigated by hospitalization with the diagnosis of venlafaxine addiction along 10 weeks, was gradually decreased and stopped. However, this detoxification period was hardly carried out due to limited mental capacity of the patient. This case shows that the antidepressant addiction is able to develop in patients who have not drug and alcohol usage history.