A new study conducted by the US Defense Department shows that drone pilots are equally susceptible to mental health problems and disorders compared to pilots of manned aircraft. Despite typically carrying out their duties a safe distance away from the battlefields of Afghanistan and Iraq, individuals behind the controls are falling victim to anxiety, depression, and stress just as frequently as traditional pilots.

The study was conducted by the Armed Forces Health Surveillance Center, and while it stops short of calling out specific reasons for the link, The New York Times says its authors have several possible explanations. “Remotely piloted aircraft pilots may stare at the same piece of ground for days,” co-author Jean Lin Otto told the Times. “They witness the carnage. Manned aircraft pilots don’t do that. They get out of there as soon as possible.” Aside from frequent exposure to violence, drone operators have cited long hours and other job demands as further stress instigators. It's a worrying development military officials will need to address as the US increases its reliance on remotely piloted craft; according to the Times, the Air Force is currently training more drone pilots than those headed for fighter jets and bombers combined.