Researchers at McGill University and the Douglas Institute in Montreal gave the drug to people with PTSD, timed to arrive just before each weekly session of recalling their traumatic memory in detail, over six weeks.
In the 60-person trial, PTSD symptom scores dropped significantly more on propranolol than on placebo, with a gap of about 11.5 points on the clinician-rated scale and over 14 points on the scale patients filled out themselves. The pill was taken 90 minutes before each session, so it was active while the memory was recalled and stored again.
The theory is reconsolidation: each time a memory is pulled back into mind, the brain rebuilds it, briefly vulnerable to change, and propranolol appears to blunt the emotional charge that gets written back in. The trial was small and the effect has not yet been replicated at scale, and the drug is not a stand-alone PTSD treatment outside a research protocol.
Read the original study
Brunet et al., American Journal of Psychiatry, 2018 · doi.org/10.1176/appi.ajp.2017.17050481
An old pill, aimed at a memory.
Source
- Brunet, A., Saumier, D., Liu, A., Streiner, D. L., Tremblay, J., & Pitman, R. K. (2018). Reduction of PTSD Symptoms With Pre-Reactivation Propranolol Therapy: A Randomized Controlled Trial. The American Journal of Psychiatry, 175(5), 427–433. https://doi.org/10.1176/appi.ajp.2017.17050481