In March 2015, Germanwings Flight 9525 crashed into the French Alps, killing all 150 people onboard. An investigation found that the copilot deliberately steered the plane into the mountainside. It also revealed that he had a history of depression. Among workers, untreated depression can affect the ability to perform tasks and—as the Germanwings incident shows—in rare instances, can result in devastating consequences. In one of the first studies of its kind, researchers at the NIOSH-funded Harvard Education and Research Center (ERC) looked at the prevalence of depression among commercial airline pilots.

Researchers used an anonymous web-based survey of pilots recruited from unions, airline companies, pilot groups, and aviation safety organizations to ask about depression and other health issues. Between April and December 2015, 1,837 airline pilots completed the survey. More than 12% of survey respondents who answered the survey’s health questions met the criteria for depression and 4% reported having suicidal thoughts within the prior two weeks. Pilots who reported using medication to aid sleep and who experienced sexual or verbal harassment were significantly more likely to be depressed. The findings were published in the journal Environmental Health.