Co-Pilot of Germanwings Airbus Deliberately Crashed Plane

The Marseille prosecutor has released a statement on BBC News concerning this deliberate act. The co-pilot was a German, aged 28 years old, named Andreas Lubitz. According to conversations on the black box voice recordings the Captain left the cockpit, presumably to use the toilet, the co-pilot manually selected the aircraft to descend at a rapid speed and crash into the mountains. The Captain is heard on the black box banging on the locked cockpit door trying to re-enter the cockpit realising the aircraft was in a deep, abnormal descent. One of the black boxes is still missing. 

LWDLIK - Reminiscent of EgyptAir flight 990. Perhaps pilots should be regularly psychologically evaluated and drug tested?