Should we be more concerned about the mental health of pilots?

The dominant theory to explain the crash this week of Germanwings flight 9525 in France has shifted to suicide by the plane's co-pilot, Andreas Lubitz.

According airline CEO Carsten Spohr, Lubitz spent a few months on hiatus during his training.

Due to Germany's strict medical safety rules, the airline has no knowledge of the exact reason for the pilot's brief departure.

The rise of this crash theory has immediately focused attention on the mental health of the world's commercial airline pilots.

Although new airline pilots receive psychological screening prior to getting hired at an airline, they do not receive any psychological evaluations once they're on the job.

According to airline pilot and author of the book "Cockpit Confidential" Patrick Smith, flight crews do receive annual or biannual medical checkups ups that include criteria relating to mental health.

Pilots can be grounded for everything from physical ailments to mental health issues, such as depression and anxiety.

With that said, airline pilots sometimes don't get the help they need.

"Pilots are human beings and subject to the same weaknesses as every other professional," Smith said in an email to Business Insider. "All the medical testing in the world, meanwhile, isn't going to preclude every potential breakdown or malicious act."

"I think the rarity of crew sabotage incidents speaks to how well the system works," Smith continued.

It's true that instances of pilot suicide are exceedingly rare and flying is incredibly safe. With millions of flights taking of and landing without incident each year, air travel has never been safer. And pilot suicides have accounted for a miniscule percentage of crashes.

But more can be done to prevent such tragedies, however rare, from taking place.

"Pilot suicides do happen, but people don't talk about it," experienced international airline pilot and author Karlene Petitt told Business Insider. "Airline pilots work in a very ego-heavy atmosphere because of the nature of the work requires them to confidently take on some life-threatening situations."

As a result, Petitt believes the industry needs to increase the level of mental health training and education so that pilots are in a better position to self diagnose any issue they may be having so they can seek help.

In addition, Petitt also believes that the airline industry needs to create an open environment where pilots are always comfortable in admitting they have an issue.

Pilots who fly the airliners we travel on are just people. They're susceptible to same maladies that plague us all. But this shouldn't change our perception of airline safety.

"For passengers, at a certain point there needs to be the presumption that the men and women in control of your airplane are exactly the highly skilled professionals you expect them to be, and not killers in waiting," Smith said.