Veterans Administration (VA) statistics suggest that veterans are disproportionately affected by suicide. While only one out of every ten Americans has served in the military, veterans accounted for nearly one out of every five suicides in 2014. Despite stepped-up efforts by the VA to help prevent such tragic outcomes a major hurdle remains: it can be nearly impossible to predict who is at risk of suicide.
The problem is not a lack of research. “A lot of people have been trying to find out for a long time why these behaviors occur,” says Lauren Forrest, a graduate student in Miami University’s Department of Psychology. Even so, recent analyses of data from 50 years’ worth of studies show that the ability of mental health professionals to predict suicidal behavior is still no better than chance.
“We need to study novel risk factors, to look at new things that might be related to people injuring themselves,” says Forrest.
She suggests interoception as one potential candidate. Interoception is the ability to perceive physiological sensation – including hunger, itch, pain, and emotions – inside the body. Forrest’s hypothesis is that people who have low interoception, who are relatively “tuned out” to pain or to sensations associated with fear, might be at greater risk for harming themselves.
“It’s kind of like when someone’s been to the dentist and had a shot of Novocaine,” says Forrest. “Their tongue goes numb, and it would be really easy for them to bite their tongue and cause significant damage, because they can’t feel it.”
Forrest’s work recently caught the attention of the Military Suicide Research Consortium, which has given her a $2,000 grant to complete an interoception study, under the supervision of assistant professor April Smith.
To establish a baseline of interoception, Forrest will compare subjects’ self-reported responses to physical and emotional stimuli with measurements of their physiological responses to those stimuli. Both people with a history of self-injurious behavior and people without such a history will be included in the study, so that their responses can be compared.
“We want to understand how this misperception is happening” in people with low interoceptive ability, says Forrest. “Is it more of a psychological thing or is it more of a physiological thing? Do their bodies simply not produce these sensations like they should?”
To help answer those questions, Forrest and two undergraduate research assistants will continue to follow participants with a history of self-injury for six months after collection of the baseline data. They will ask the participants to report weekly on the number of times they injured themselves, thought about suicide, and/or attempted suicide. Forrest and her team will then look for correlations between those reports and the self-reporting and physiological data collected during the baseline phase.
Given the incidence of suicide among veterans, it’s easy to see why the Military Suicide Research Consortium is interested this kind of research. But service members and veterans will not be the only ones to benefit.
“Suicide and non-suicidal self-injury are really huge public health problems with very significant consequences,” says Forrest.
If she’s able to find a link between reduced interoception and self-injurious behavior, Forrest’s work may lay the groundwork for further research that eventually leads to clinical interventions. For instance, it may one day be possible for healthcare professionals to administer questionnaires and/or physiological assessments that help predict which patients are at risk of self-injury and refer them for treatment before it’s too late.
That’s an outcome everyone can live with.
Written by Heather Beattey Johnston, Associate Director of Research Communications, Office for the Advancement of Research and Scholarship, Miami University.
Photos courtesy of Lauren Forrest.