Pupil dilation in reaction to seeing negative emotional faces appears to predict the risk for experiencing a relapse of major depressive disorder (MDD), according to a new study at Binghamton University, State University of New York.
Specifically, really high or really low pupil dilation to angry faces was linked to an increased risk for depression relapse, whereas only low dilation to sad faces was associated with risk. High dilation to sad faces was actually protective.
For the study, researchers at Binghamton University, led by Ph.D. student Anastacia Kudinova, aimed to determine whether physiological reactivity to emotional stimuli, assessed through pupil dilation, could be used as a biological marker of risk for depression recurrence among individuals who are known to be at a higher risk due to having previous history of depression.
The study involved 57 women with a history of major depressive disorder. The researchers recorded the change in pupil dilation in response to angry, happy, sad, and neutral faces. They discovered that the participants’ pupillary reactivity to negative (sad or angry faces) but not positive stimuli prospectively predicted MDD recurrence.
“The study focuses on trying to identify certain markers of depression risk using measures that are readily accessible, reliable and less expensive,” said Kudinova. “It is something we can put in any doctor’s office that gives us a quick and easy objective measure of risk.”
The research team discovered that both high and low reactivity to angry faces predicted risk for MDD recurrence. These findings suggest that disrupted physiological response to negative stimuli represented through pupillary dilation could serve as a physiological marker of MDD risk, thus presenting clinicians with a convenient and inexpensive method to help determine which at-risk patients are more likely to experience depression recurrence.
“It’s a bit complicated because different patterns of findings were found for pupil reactivity to angry versus sad faces. Specifically, really high or really low pupil dilation to angry faces was associated with increased risk whereas only low dilation to sad faces was associated with risk (high dilation to sad faces was actually protective),” said Brandon Gibb, professor of psychology at Binghamton University and director of the Mood Disorders Institute and Center for Affective Science.
Major depressive disorder is characterized by a constant state of low mood, hopelessness and despair. Sufferers often experience fatigue, impaired concentration, sleep problems, restlessness, and thoughts of suicide.
Source: Binghamton University