BINGHAMTON, NY - Pupil dilation could identify which individuals are at greatest risk for depression following natural disasters and help lead to targeted interventions, according to new research from Binghamton University, State University of New York.
Researchers at Binghamton University recruited 51 women who were living in the greater Binghamton, N.Y., area at the time of a catastrophic 2011 flood and who reported that they had been impacted by the flood to some extent. Many of the women were already at high-risk for future depression, as about 40% had a prior history of major depressive disorder. The researchers' findings indicated that women who experienced higher levels of flood-related stress were more likely to experience increases in depressive symptoms following the flood if they also displayed a physiological risk factor for depression (decreased pupil dilation to emotional faces). That is, differences in pupil dilation helped to identify which women were most likely to become depressed in the aftermath of the flood.
"As part of a study we were already running examining risk for depression, we had collected a measure of pupil dilation. During the course of the study, the flood happened and we were able to assess the degree to which the flood impacted them and their levels of depression before and after the flood to see how much their depression increased," said Brandon Gibb, professor of psychology at Binghamton University and director of the Mood Disorders Institute and Center for Affective Science.
The study is the first to examine how pupillary response to emotional faces may interact with life stress to predict risk for future depression. If replicated and extended, the current findings may further the understanding of how this physiological risk factor plays a role in stress and depression and also aid in the identification of those most at risk following negative life events, wrote the researchers.
Mary Woody, a PhD student at Binghamton University and lead author of the study, explained that the study was inspired by well-established theories of depression. "Some theories of depression suggest there are vulnerabilities for depression, like decreased pupil dilation to emotional faces, that increase risk for depression following stressful life events. Because we were already following families at risk for depression over time, the flood provided an opportunity for a "natural experiment" as we were able to examine how a stressor occurring outside a person's control interacted with vulnerabilities to predict future depression."
"After major stressful life events like natural disasters, research suggests only about 20 to 25 percent will go on to develop a depressive disorder. Because there are limited resources following a natural disaster, it is too expensive to provide psychiatric care to entire affected communities," said Woody. "This project suggests that pupil dilation could be used to identify those who are at greatest risk for depression."
For example, previous research has shown that pupillometry can predict who responds best to psychotherapies such as cognitive therapy for depression. The current study builds on this research by suggesting that pupillometry could guide individualized intervention for depression following stressful life events such as natural disasters.
"It is certainly plausible that individuals displaying decreased pupillary response to emotional stimuli and higher levels of disaster-related stress may be good candidates for cognitive therapy to alleviate their depression," said Woody.
However, the researchers say that future research is needed to determine if pupillometry could predict response to intervention efforts following natural disasters.
Other contributors to this research include Anastacia Kudinova, PhD student at Binghamton University; Katie Burkhouse, postdoctoral fellow at University of Illinois, Chicago; Max Owens, assistant professor of psychology at the University of South Florida, St. Petersburg; and Greg Siegle, associate professor of psychiatry at the University of Pittsburgh School of Medicine.
The paper, "Pupillary response to emotional stimuli as a risk factor for depressive symptoms following a natural disaster: The 2011 Binghamton flood," will be published in Clinical Psychological Science.