Propranolol Treatment of Traumatic Memories (PTTM)

Traumatic memories are responsible for significant emotional distress and disability. They are a cardinal feature of Posttraumatic Stress Disorder (PTSD). Re-experiencing the original traumatic event in a number of different ways (e.g. nightmares, intrusive recollections and dissociative flashbacks) is accompanied by distressing symptoms. The reconsolidation theory of memory proposes that when long-term memories are reactivated, they remain labile for several hours before conversion back to long-term memory. During this period they are susceptible to amnestic agents, like propranolol. Propranolol Hydrochloride will be compared to placebo in subjects who have emotional distress associated with re-experiences of traumatic events, whether in the context of PTSD or not. Two doses of propranolol or two doses of placebo will be given at the first visit. The objective of the trial is to determine the effectiveness of brief treatment with propranolol on subjects with traumatic memories and associated symptoms. The research hypothesis is that propranolol will be more effective than placebo, as determined by the measures used, and that this positive outcome will support the reconsolidation theory of memory. The subjects will undergo clinician rated assessments/scales to determine the presence of pre-treatment mental disorders. Subjects will complete self-rating measures/scales to determine the impact of the traumatic experience. Blood pressure and pulse rates will also be recorded. Post-treatment outcomes using the same instruments to determine changes at four weeks will be recorded. The differences will be compared and subjected to statistical analysis. There is an optional component of the study for subjects allocated to the placebo group. At the end of the study, these subjects will be given the opportunity of taking two doses of propranolol and attending a single follow-up session four weeks later for a further interview, rating scale and questionnaire completion. This will provide the subjects who were on placebo an opportunity of possibly benefiting from the active treatment.