At least one in five U.S. military veterans who have experienced trauma are at greatly elevated risk for depression, suicide, or substance abuse even though they do not meet all criteria for post-traumatic stress disorder (PTSD), according to a new Yale-led study.
The study of 1,484 U.S. veterans, published June 1 in the journal World Psychiatry, highlights the scope and burden of sub-threshold PTSD, or a collection of symptoms that aren’t complete enough or severe enough to earn a PTSD diagnosis.
“You have a very large group of people who may be in need of treatment, but are often overlooked in clinical settings,” said Yale clinical psychologist Robert Pietrzak, director of the Translational Psychiatric Epidemiology Laboratory of the Clinical Neurosciences Division of the U.S. Department of Veterans Affairs National Center for PTSD and senior author of the study.
PTSD is a debilitating condition marked by intrusive memories of a traumatic event. It is also marked by a pattern of avoiding things or people that conjure up those memories, an increase in negative thoughts and feelings, and symptoms of hyper-arousal — such as increased anger, trouble concentrating or sleeping, and being easily startled. All of these symptoms must be present, be of certain severity and duration, and cause clinically significant functional impairment before the condition is diagnosed. Although not recognized as a formal psychiatric diagnosis, subthreshold PTSD is an overlooked trigger of a variety of mental health problems, some researchers have come to believe.
A team led by Pietrzak and lead author Natalie Mota, a former post-doctoral researcher in Pietrzak’s lab who is currently at the University of Winnipeg, suspected that a much larger group of veterans who experience moderate levels of PTSD symptoms are at greater risk for other psychiatric disorders.
The new study found that 8% of veterans were diagnosed with PTSD but 22.1% met criteria for sub-threshold PTSD during their lives. Further, in addition to 4.5% of veterans diagnosed with PTSD within the last month, 13.1% experienced sub-threshold symptoms. Those who did had substantially higher rates of co-occurring psychiatric problems. For instance, those with sub-threshold PTSD had a 20.1% chance of suffering major depression in their lifetimes, compared to just 4.4% of veterans without those symptoms. Nearly four times as many reported suicidal thoughts than veterans without sub-threshold PTSD (12.2% vs. 3.4%). These rates were even more elevated among veterans diagnosed with PTSD.
“The results were striking,” Pietrzak said. “We found three, four, five times higher rates of some disorders in veterans with sub-threshold PTSD.”
Clinicians, he says, should be vigilant in assessing, monitoring, and possibly treating sub-threshold PTSD symptoms in those who have experienced any form of trauma, whether it be related to combat or the sudden unexpected loss of a loved one.