Often our bodies provide clues of an impending breakdown: Palpitations may signal a future heart condition, loss of breath, a brief bout of bronchitis. Are there similar clues of future mental illnesses lying hidden within the folds of our brains? By measuring activity in the amygdala, a new Duke University study finds, scientists may predict who will become depressed or anxious in response to a stressful life event.

No one, it seems, escapes having a really bad time at some point in life. “We all experience a host of common life stressors such as the death of a family member, medical illness, and financial uncertainty,” noted the Duke researchers in the introduction to their study. Though most of us do not buckle, some people may find themselves unable to stand tall under such intense pressure and develop some chronic psychological problem, such as depression or anxiety. Naturally, any doctor would prefer being able to predict in advance those likely to become ill rather than wait for the crisis to unfold.

What sign or biomarker, though, predicts mental illness? This was the exact question raised and then answered by a team of Duke researchers led by Dr. Ahmad Hariri, a professor of psychology and neuroscience and lead author of the study. Hariri and his colleagues began their study by collecting data, including brain scans, from 340 healthy college students. Their scans highlighted a particular brain region: the amygdala, an almond shaped structure that helps process emotion, including fear responses. While undergoing an MRI, the students looked at angry faces, which signal danger, as a way to trigger the amygdala. Meanwhile, the scientists recorded the intensity of activity in this brain region.

Every three months after the scan, participants in the study completed an online survey documenting stressful life events in addition to a questionnaire that assessed symptoms of depression and anxiety. The researchers followed up on the students, in some cases, for up to four years.

High Activity = Severe Symptoms

What did the researchers discover after analyzing and comparing all the data? Students with the most reactive amygdalae at study's start showed the most severe symptoms of anxiety or depression when encountering a highly stressful life event later. By comparison, participants with jumpy amygdalae who did not experience high stress events never showed symptoms.

The research is part of the Duke Neurogenetics Study, a long-term study that includes genetic research seeking to illuminate the reasons why some people are more vulnerable to developing depression, anxiety, and other mental health problems.

"To find that a single measure of the brain can tell us something important about a person's psychological vulnerability to stress up to four years later is really remarkable and novel,” Hariri stated in a release. In fact, it is the ultimate crystal ball.

Source: Swartz JR, Knodt AR, Radtke SR, Hariri AR. Neural biomarker of vulnerability to stress. Neuron. 2015.