Mr. A was a 25-year-old man with a previous history of benzodiazepine, "ecstasy," LSD, and cannabis abuse. There was no other significant medical or psychiatric history. Mr. A reported being bothered by flashbacks of flashes of colors, trails of images of moving objects, body image distortion, and spontaneous imagery. These episodes usually lasted between a fraction of a second and a few minutes. They were severe enough to cause clinically significant distress, anxiety, and impairment in social and occupational functioning. After obtaining written consent, we started Mr. A on a regimen of 0.025 mg of clonidine three times a day. After 1 month of treatment, he reported considerable improvement in both the number of flashbacks and the accompanying anxiety. Over next 2 months, symptoms disappeared completely; we then discontinued the clonidine. Mr. A remained symptom free over a 6-month follow-up period.