Do it yourself, I'm travelling.
I love all the "motive is unclear" stuff from the people giving this trash traitor and maker of orphans MILLIONS OF DOLLARS WORTH OF PUBLICITY.
Hey, he's a psychiatrist. His actions make perfect sense!
It's not as though he knew what to say to game the system and avoid being deployed.
Or could prescribe himself drugs, either.
Face it- shooting up a base full of soldiers is the PERFECT way to avoid the three worst things about deployment- uncertainty, risk of injury, and a dramatic decline in personal living conditions.
Yep, he did it because he didn't want to be deployed. Its the only POSSIBLE explanation.