Military service members who have a history of insomnia are at greater risk of developing posttraumatic stress disorder (PTSD), depression and anxiety after deployment than members who have no troubles sleeping, new findings have confirmed.
“Understanding environmental and behavioral risk factors associated with the onset of common major mental disorders is of great importance in a military occupational setting,” study’s lead author Philip Gehrman, assistant professor of Psychology in the Department of Psychiatry, member of the Penn Sleep Center, and the Philadelphia VA Medical Center said.
“This study is the first prospective investigation of the relationship between sleep disturbance and development of newly identified positive screens for mental disorders in a large military cohort who have been deployed in support of the recent operations in Iraq or Afghanistan.”
For the purpose of the study, researchers at the Perelman School of Medicine at the University of Pennsylvania and the Naval Health Research Center looked at 15,204 service members.
Once the servicemen and women completed their first deployment they were required to fill in two questionnaires (before and after first deployment) detailing their mental health and sleep patterns from 2001 to 2008.
While at baseline most soldiers were not diagnosed with any psychiatric disorder or have a history of one, but in follow-up questionnaires, 522 soldiers had post-traumatic stress disorder (PTSD), 151 had anxiety disorder, and 303 suffered from depression.
Furthermore, 50 percent of the study subjects reported combat-related trauma and 17 percent had pre-existing insomnia prior to their deployment.
Soldiers who slept six or fewer hours each night before deployment had higher risk of developing PTSD, researchers found. Furthermore, soldiers who continued to sleep inadequately even post deployment were also at high risk of developing PTSD.
Higher stress levels and smoking also increased the risk of developing PTSD.
However, soldiers with pre-existing insomnia had the highest chances of developing PTSD after deployment.
Likewise, insomniacs were most likely to anxious and feel depressed as compared to those who get sufficient sleep, researchers highlighted.
“We found that insomnia is both a symptom and a risk factor for mental illness and may present a modifiable target for intervention among military personnel. We hope that by early identification of those most vulnerable, the potential exists for the designing and testing of preventive strategies that may reduce the occurrence of PTSD, anxiety, and depression,” said Gehrman.
The findings of the study appear in the July 2013 issue of the journal SLEEP.