Clinical psychologist Alain Brunet of McGill University in Montreal doesn´t usually torture his patients. But lately he has been pressing those with post-traumatic stress disorder, or PTSD, to relive emotionally scarring incidents. For some it´s rape, others battlefield trauma. When his patients get particularly upset-crying, shaking, blood pressure rising-he gives them a 25-year-old hypertension drug called propranolol. The idea, though, is not to lower their blood pressure.