MONTREAL -- Treatment of posttraumatic stress disorder with the beta-blocker propranolol might interrupt memory reconsolidation by inhibiting protein synthesis in the brain, reported researchers at the International Society for Traumatic Stress Studies.
"It does not erase memories; this is a misnomer," clarified Alain Brunet, Ph.D., of the department of psychiatry at McGill University and a researcher at the Douglas Mental Health Institute, both in Montreal.
Dr. Brunet presented several studies conducted by his group that suggest this pharmacologic interruption of memory might dampen emotional response to the information, presenting a promising treatment opportunity for posttraumatic stress disorder (PTSD).
Current treatment for PTSD is centered on psychotherapy that focuses on exposure to the traumatic memory and learning new responses to it, Dr. Brunet said. But a recent analysis found that only about one-third of patients treated this way experience a lasting, clinically meaningful improvement, he said.
Propranolol treatment takes a different approach. It is based on the notion that memories, once they are consolidated, can be retrieved, and they exist in a labile state during which they are susceptible to modification until they are reconsolidated. During the labile window of opportunity, which is believed to be several hours, administration of propranolol can strip the memory of its emotional meaning, making it less stressful, he said.
In a randomized, controlled trial involving 19 chronic PTSD patients with an average symptom of duration 10 years (J. Psychiatr. Res. 2008;42:503-6), Dr. Brunet and his colleagues asked the patients to recall their memory by writing a trauma script and outlining the details of their traumatic experience and the emotions they felt.
Nine patients were then given a two-dose regimen of fast-acting propranolol (40 mg) immediately after memory recall, followed by an extended-release propanolol dose (60 mg) 75 minutes later, and the other 10 patients received placebo. …