Stanford researchers measured brain activity in PTSD patients before and after psychotherapy and found that they could predict how well patients would respond to treatment.

A pair of studies led by researchers at the Stanford University School of Medicine demonstrates that scientists can predict, with a high degree of accuracy, which patients with post–traumatic stress disorder will respond to a method of psychotherapy often used to treat the condition.

The researchers showed how the treatment, prolonged exposure therapy, works in the brains of PTSD patients and linked brain activity patterns to how well patients responded. The results could lead to personalized treatment for PTSD.

The studies were published online July 18 in The American Journal of Psychiatry.

“We understand vanishingly little about how psychotherapy works and for whom it works well,” said Amit Etkin, MD, PhD, the senior author of both studies and an associate professor of psychiatry and behavioral sciences at Stanford. “It’s not even a knowledge gap — more like a knowledge ravine. This is especially an issue for PTSD because the only effective treatment is psychotherapy.”

Lead authorship of the papers is shared by Stanford postdoctoral scholar Gregory Fonzo, PhD, and former Stanford postdoctoral scholar Madeleine Goodkind, PhD, now a psychologist at the New Mexico Veterans Affairs Health Care System and an adjunct assistant professor of psychiatry at the University of New Mexico School of Medicine.

Prolonged exposure therapy for PTSD consists of a series of sessions and homework assignments that lead patients to gradually approach trauma–related memories and situations. Patients begin by imagining scenarios that trigger their PTSD symptoms — such as a crowded park. Then, they work up to deliberately putting themselves in those scenarios. Revisiting traumatic experiences in this manner can, over time, allow the brain to slowly reduce its response to emotional triggers.

To learn how prolonged exposure therapy works in the brain, the studies used functional magnetic resonance imaging to measure the brain activity of 66 patients diagnosed with PTSD as they completed five tasks tapping a variety of emotional and cognitive functions.

After the initial brain imaging, about half the participants underwent nine to 12 sessions of prolonged exposure therapy; the remainder did not. At the end of the trial, all participants went through the same emotional response and regulation tests while researchers measured brain activity. One of the studies focused on whether brain activity levels before treatment could help scientists predict which participants would respond well to prolonged exposure therapy. The researchers measured how active certain brain regions were during the five tasks and looked for associations with reduced symptoms post–treatment.

Prior to receiving prolonged exposure therapy, patients with both lower activity in the amygdala and higher activity in various regions of the frontal lobe while viewing faces with fearful expressions showed a larger reduction in PTSD symptoms following therapy.

The researchers also found that patients with greater activation in a deep region of the frontal lobe when ignoring the distracting effects of conflicting emotional information – such as a picture of a scared face with the word “happy” written across it – responded better to exposure therapy.

Using this information about how the brain responds in emotional regulation and processing tasks, the team was able to predict how effective prolonged exposure therapy treatment would be for patients with up to 95.5 percent accuracy.