By comparison, between 11% and 20% of troops from Iraq and Afghanistan, including some Air Force crew members who fly conventional warplanes, have been diagnosed with PTSD, according to the National Center for PTSD.
At the very least, the stress leaves drone crews at risk for depression and anxiety disorders, potentially affecting their performance, psychologists say.
Often, crew members don't even acknowledge that they're stressed by combat. After all, they're not directly exposed to combat smells or sounds, or the imminent threat of death — all typically associated with PTSD in ground troops.
Crews who feel stress don't say it's "because I was in combat or because we had to blow up a building or because we saw people get blown up," Ortega said. Rather, he said, they complain of shift work, schedule changes, long hours, low staffing and failure to maintain family relationships.
As one respondent complained: "Sustaining vigilance is mind-numbing." Others wrote: "Too much monotony/Groundhog Day" and "Not being around to do stuff at home."
The Air Force is considering assigning more chaplains and psychologists to drone units, said Dr. Wayne Chappelle, an Air Force clinical psychologist. It's also considering workshops on family stresses, and adding psychologists to military clinics so that crew members don't have to be referred to outside specialists.
Combat stress needs to be addressed before it affects crew performance, Chappelle said.
Crew members may not be able to escape combat stress, Ortega said.
"This is a different kind of war, but it's still war," he said. "And they do internally feel it."