New York, Feb 5 (IANS): Measuring activity of a brain region which is crucial for detecting and responding to threats, it is possible to tell four years in advance if someone would become depressed or anxious in response to stressful life events, says a study.

While some people can cope with stressful situations such as divorce, loss of a loved one or financial trouble well, others go on to develop anxiety or depression later.

A clue to this difference could be found in an almond-shaped structure deep within our brains, the amygdala, the findings showed.

"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," said senior author Ahmad Hariri, professor of psychology and neuroscience at the Duke University.

The results may eventually lead to new strategies to treat depression and anxiety and prevent them from occurring in the first place.

"With a brain marker, we could potentially guide people to seek treatment earlier on, before the disorders become so life altering and disruptive that the person can't go on," first author Johnna Swartz, postdoctoral researcher at the lab of Hariri, explained.

In the new study involving 753 participants, the researchers scanned the brains of healthy college students as they looked at angry or fearful faces, which signal danger in our environment.

Then, using functional magnetic resonance imaging (fMRI) technology, they measured activity in the amygdala to determine how active it was in response to the threatening stimuli.

The more reactive the amygdala was at the study's start, the more severe their symptoms of anxiety or depression in response to stressful events they encountered after scanning.

The study was published in the journal Neuron.