Reducing Reconsolidation of Trauma Memories With Propranolol

Inclusion Criteria: * Suffer from chronic PTSD for at least 6 consecutive months; * Obtain a score of 33 or more on the Impact of Events Scale-Revised: * For participants aged 40 years: accept to undergo an electrocardiogram assessment. The results of the electrocardiogram must be normal; * Accept to not commence taking new medications on a regular basis during the study. Exclusion Criteria: * Hypotension; * Cardiac rhythm below 55 beats per minute; * Medical conditions that contraindicates the administration of propranolol; * Previous adverse reaction to, or non-compliance with, beta-blockers; * Current use of medication that may involve potentially dangerous interactions with propranolol; * Any medication that can have an impact on cardiac rhythm; * Women who are breast feeding; * Past or present bipolar disorder or psychosis, * Present substance abuse or dependence, suicidal ideation; * Participating in psychotherapy other than support psychotherapy; * An average score above 20 on the Dissociative Experience Scale.