Propranolol a Promising Treatment for PTSD
The β-blocker propranolol may interrupt reconsolidation of traumatic memories through protein synthesis inhibition, presenting a promising treatment option for posttraumatic stress disorder (PTSD), 2 new studies suggests.
A study in which some PTSD patients received propranolol and subsequently listened to tape recordings of their trauma displayed less physiological distress than other patients who had received placebo.
Dr. Saumier reported results from a randomized controlled trial that included 19 chronic PTSD patients with an average symptom duration 10 years (J Psychiatr Res. 2008;42:503-506). The patients were asked to recall their memory by writing a trauma script, outlining the details of their traumatic experience and the emotions they felt.
Nine patients were then given a 2-dose regimen of fast-acting and then extended-release propranolol (as described above), and the other 10 patients received placebo. One week later, after review of the trauma script, patients’ physiologic responses to the memories were compared, using heart rate, skin conductivity, and corrugator electromyography (EMG) measurements.
“There were significant differences between the placebo and treatment groups on heart rate and skin conductivity tests but not on EMG,” he said. And there was a trend toward decreased symptoms, measured on the self-report Impact of Event Scale–Revised.
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Since propranolol blocks beta-adrenergic receptors — it’s a beta blocker — researchers predicted that it might prevent traumatic memories from solidifying.
Propranolol given within a specific time-window can interfere with their ability to solidify again. In more scientific terms, it can block the reconsolidation of threatening memories.
Today, cognitive-behavioral treatment alone, targeted at thoughts and emotional reactions, can provide significant help. Current guidelines for effective PTSD treatment describe controlled exposure to troubling memories in a therapeutic setting to regain cognitive mastery, and strategies to help people correct maladaptive thoughts about the event — thinking they were guilty for not saving others, for example.
Furthermore, stress-inoculation training teaches methods to reduce anxiety such as calm breathing and muscle relaxation. Symptomatic improvement can be assisted with antidepressant medications such as Prozac and other medications for insomnia.
A nice summary by Eric Jaffe appears in the APS Observer, Vol. 26, No. 8, October 2013: Building a Fearless Mind.
Citing a prominent researcher, Monfils, Jaffe notes:
Determining what makes one patient population receptive to one therapy instead of another will be an ongoing challenge.
We’re a long ways off, and the “huge gap between lab and clinic” will have to be narrowed.
More on the pharmacokinetics and mechanism of action of propranolol: