Could PTSD Be Prevented Post-Trauma?
Nationwide, about 8 million people suffer from post-traumatic stress disorder, from military veterans to victims of sexual abuse. Symptoms often persist long after the original trauma occurred, and can include everything from extreme stress or fear to vivid flashbacks.
However, while clinical professionals say treatment for PTSD, ranging from counseling to medication, has improved, experts agree there remains a need to fine-tune therapies. And one question inspires -- and puzzles -- clinicians and researchers alike. "If we intervene immediately," after a person experiences a traumatic event, says Dr. Matthew Friedman, senior advisor to the Department of Veterans Affairs' National Center for PTSD, "can we prevent the later development of PTSD?"
Friedman chaired a work group for the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, which reclassified PTSD as a trauma and stressor-related disorder (it had previously been classified as an anxiety disorder). For years, he and other experts have been advocating for a treatment, medication or otherwise, to proactively stop the development of PTSD after a person has experienced trauma. This would supplement, or pre-empt, current treatments available for those already diagnosed with the disorder.
Friedman notes that limited research has been done seeking a way to do just that. "So there's a small [amount of] interesting, flawed literature out there, where we've been trying to do this. People have been thinking in terms of prevention," says Friedman, who is also professor of psychiatry and of pharmacology and toxicology at the Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. Such preventive approaches seek to better understand and respond to brain changes that cause PTSD. The disorder turns the body's natural, healthy "fight or flight" response on its head, experts say. Instead of simply keeping a person safe from experiencing a similarly traumatic event in the future, symptoms of the disorder, like flashbacks, severely disrupt a person's life and can make a frightful memory feel like a present reality.
Unfortunately, Friedman and other experts say, much remains unknown about why some people develop PTSD in the face of trauma, while others do not, as well as the mechanisms involved. That's exactly what researchers at the Massachusetts Institute of Technology in Cambridge set out to explore -- in mice -- to provide further clues on how PTSD might be prevented in people. "There's a lot of provocative stuff out there, but nothing as elegant as what's in this paper," Friedman says of the findings published in July in the journal Biological Psychiatry.
The study drew on prior research finding that people are more likely to develop PTSD if they were chronically stressed before they endured a traumatic event or series of events. "Lots of people experience trauma, some get PTSD from it," says Ki Goosens, senior author of the study and an assistant professor of neuroscience and investigator in MIT's McGovern Institute for Brain Research. "One notable difference is the people with PTSD have this really intrusive memory that sort of pops up when they're not trying to think about [the traumatic event or when] they see something similar and it reminds them of it."
To evaluate why that is, MIT researchers have focused on the amygdala, part of the brain that's been shown to help us process emotions. One function of this brain structure is to encode fearful memories. The research team found that in chronically stressed animals that experienced PTSD symptoms, the release of the chemical serotonin -- which is associated with feelings of pleasure -- also seems to play a role in solidifying fearful memories.
However, when researchers blocked amygdala cells from interacting with serotonin after trauma, the chronically stressed mice didn't develop PTSD symptoms. Goosens notes that the U.S. Food and Drug Administration has already approved a drug called agomelatine for use as an antidepressant, which performs a similar function by blocking the same type of serotonin receptor. She thinks it would be worthwhile for other researchers to test agomelatine in people as a way to possibly prevent PTSD.
The findings from her own animal research don't suggest causing amnesia in people to rid them of bad memories, but that by blocking serotonin, you could weaken and normalize the memories, Goosens says, preventing them from spiraling into PTSD. "The idea is that you can give a drug shortly after a trauma and block what we call the consolidation process of that memory."
She plans to do more testing in animals to study this theory. Friedman echoes that more study is needed, including to replicate the findings. "We need to move carefully and rigorously to understand the implications of this -- but it's a very exciting lead," he says. Experts also point out that studies in people are, of course, the only way to truly know if the effects observed in mice translate to humans.
Dr. Rachel Yehuda, professor of psychiatry and neuroscience and director of the Traumatic Stress Studies Division at the Icahn School of Medicine at Mount Sinai in New York City, questioned the take-aways from the research.
"Blocking memory encoding is interesting science but the problem with PTSD isn't the memory, it's the fact that a traumatic event occurred and the meaning of the memory," says Yehuda, who also directs the Mental Health Patient Care Center at the James J. Peters Veterans Affairs Medical Center in the Bronx. "People who can't remember all or some of the event but know it happened are sometimes highly distressed by the gaps in memory or simply by the fact that something terrible occurred, even though they can't remember it." She adds that previous research into strategies to reduce the encoding of memories has not borne fruit. "It may be a better strategy to target PTSD prevention by changing someone's emotional state in the early aftermath of trauma, not their memory per se," she says.
Whatever form treatment might take, advocates for earlier treatment are seeking options to intervene mere hours after a traumatic event occurs, such as on the battlefield or in an emergency room, rather than the weeks, months or longer a person might otherwise wait to seek help. Experts also emphasize that those who think they're experiencing PTSD shouldn't delay seeking treatment from a professional, ranging from psychotherapy -- with cognitive behavioral therapy, which focuses on changing thought patterns and associated behaviors, shown to be the most proven for PTSD -- to medication. And while there's disagreement about the best course for early intervention, consensus is building that a more proactive approach to prevent the mental health disorder is needed. This reflects the philosophical shift from prevention to reactive treatment that's already occurred in other areas of medicine, from vaccinating against measles to controlling high blood pressure to stave off heart disease.
"Prevention of PTSD is possible and important, but this must be done by reversing the [brain] circuitry that sustains overly aroused or blunted reactions," Yehuda contends. "There is a sweet spot where someone's reaction to trauma is appropriate distress which lessens over time. Helping someone be present with their distress rather than avoid their feelings -- after all something terrible has happened -- facilitates the process of natural recovery."
Michael Schroeder is a health editor at U.S. News. You can follow him on Twitter or email him at mschroeder@usnews.com.
