Actors take it. // Cardiac patients take it. // People with post-traumatic stress disorder might one day take it. // Could a beta-blocker free victims from memories that just won’t go away?
Reversal of Misfortune
A first kiss, a summons to the principal’s office, JFK’s assassination, the birth of a child—these are the memories that remain startlingly vivid even decades after the events occurred. It’s not necessarily their content that makes them compelling but rather the intensity of feeling they provoked. Any emotional experience, positive or negative, triggers the release of stress hormones, particularly epinephrine (adrenaline), that make us instantly alert and prepared to fight, flee or enjoy. And lest we forget what stirred us up, epinephrine also helps sear the details of intense experiences into our long-term memory.
Extremely embarrassing or painful memories usually weaken with the passage of time. But in a cruel irony, the most horrific memories—of child abuse, combat, being trapped in the World Trade Center—can remain as intense and terrifying as if they had occurred just moments before. In his clinical practice devoted to treating post-traumatic stress disorder, or PTSD, Alain Brunet, assistant professor in the department of psychiatry at McGill University in Montreal, listens to accounts of debilitating nightmares and flashbacks, of lives spent sidestepping places and situations that might trigger a memory, of severe panic attacks and despair of ever connecting with people as relationship after relationship fails.
Acute stress not only deeply and indelibly burns a memory in place immediately after trauma but also, in a pernicious feedback loop, may prompt the release of additional adrenaline during each recall of the terrible event, intensifying the memory. So rather than fading, memories become even more painful, “often ruining people’s lives,” says Brunet.
Until recently, the most Brunet could offer patients was cognitive behavioral therapy, which helps people control their fears as they teach themselves that the things they associate with their traumas—a red car, say, or a loud noise—aren’t inherently dangerous. Yet while two-thirds of individuals with PTSD initially get relief from psychotherapy, according to Brunet, about half will relapse within a year, typically when they are stressed or encounter the anxiety-provoking trigger in a new context. “Therapy doesn’t break the fear association—you just have new learning laid over old learning,” says Brunet. “It’s been impossible to extinguish the fear in every context.”
Now new research with an old drug is showing signs of being able to manipulate a learned fear so that an excruciating memory turns into a merely painful one. Propranolol, a beta-blocker developed 25 years ago, prevents the epinephrine spikes that can overstimulate the hearts of people with hypertension and cardiac disease, and may also guard against the intensifying effect of epinephrine on memory. “By giving a beta-blocker to people with PTSD, we think we can target the traumatic memory rather than simply teach people how to inhibit it,” says Brunet.
This isn’t well-established science. So far, only a handful of trials have supported the idea that it’s possible to fend off a cripplingly traumatic memory, and even those small successes have required almost immediate action, within hours of seeing or experiencing something you wish you could forget. Even more experimental is the next step, a controversial approach that seeks to attenuate the intensity of recalling a long-ago trauma. Yet even if some of today’s thinking turns out to be wrong, it could entice researchers down unexplored pathways that lead to more effective therapies or simply expand scientific horizons, laying the groundwork for future discoveries.