We Might Be Able To Suppress Bad Memories Using Anesthetics One Day
Most of us have uncomfortable, frightening, painful, or downright traumatic memories that we'd rather not be able to recall. For people suffering from particular mental illnesses—including PTSD, anxiety disorders, and other psychiatric conditions—finding relief from recurring difficult memories is an important goal of treatment and a necessary step on the path toward healing.
Now researchers may just have discovered a potential way to facilitate this type of relief: A new study just published in the journal Science Advances has demonstrated it may be possible to actually suppress bad memories by applying an anesthetic just as a memory is being recalled.
How does it work?
Researchers showed 50 people slideshows involving an unpleasant story. A week later, the researchers showed the participants a reminder meant to make them recall the story. Once the memory was activated, some of the participants received an intravenous shot of propofol (an anesthetic). After 24 hours, those who'd received the shot were less able to recall the unpleasant story.
How is this possible? It has to do with the way memories form and get filed away in the brain. Everything you experience enters the brains as a series of physical and emotional sensations that get interpreted, analyzed, and then consolidated into a memory, whether to be kept for the short term or long term. When a memory is first created, it's initially quite malleable, sensitive to modification, the researchers explain in the paper—a memory can actually be shifted, blurred, or otherwise changed before it's consolidated. And recent research has actually found that when a memory is reactivated, it must go through a reconsolidation process to restabilize and "keep" the memory, during which it again becomes susceptible to modification, as demonstrated in this study. (Past research has also shown that deliberately recalling memories is an important part of the process of being able to relinquish them—a process called "intentional forgetting.")
As for the use of anesthesia as a mechanism for memory disruption, "neuroimaging data demonstrate that general anesthetics disrupt activity in the hippocampus and amygdala, brain areas critically involved in emotional memory," the researchers explain.
Will it really be able to help people heal from trauma?
With further testing, the team believes their findings could point to a potentially effective noninvasive treatment method. "The adjustment of maladaptive thoughts and behaviors associated with emotional memories is central to treating psychiatric disorders," the researchers write in the paper. "A method to selectively impair reconsolidation of specific emotional or traumatic memories in humans could translate to an effective treatment for conditions such as post-traumatic stress disorder."
Importantly, of course, being able to weaken the memory of an unpleasant story is different from weakening the memory of a traumatic event that happened to you personally, which the researchers do acknowledge in the paper.
"These emotional memories remain quite distant from those formed during truly stressful life experiences. While here we provide a proof of concept that a routine anesthetic procedure impairs reconsolidation and could potentially be used to treat psychiatric disorders in which abnormal emotional memory plays a role, clinical trials are required to apply these findings to patients with pathological, traumatic memories," they write. "Disorders such as PTSD are multifaceted disorders. PTSD involves recurrent, intrusive recollection of the trauma memory and peritraumatic memory disturbances, and these different facets may vary in sensitivity to alteration following reactivation."
While bearing in mind the prospect of being able to help people struggling to deal with painful life experiences that haunt them, it's also important to keep in mind the potentially sinister route this line of scientific development can take us: If a shot proves effective in "erasing" a memory, it can be a little frightening to think of what could happen if such a tool fell into the hands of the wrong people with less well-intentioned motives.
Overall it's a fascinating development in the realm of mental health, and we'll have to wait and see where the science takes us.