Rumor posted in comments section after a yahoo article:
“This is from Rumor Control but they said that Lufthansa was conducting a investigation on him. Maybe he wanted to go out...with a little revenge.”
Also, found this: Daily Mail UK Andreas Lubitz had to STOP training because he was suffering depression and 'burn-out'. German police make 'significant discovery' at his flat
http://www.dailymail.co.uk/news/article-3012053/Andreas-Lubitz-Germanwings-flight-9525-French-alps-crash-French-alps-Germanwings-plane-crash-Airbus-A320-Barcelonnette.html
He is awful young to be flying that large a plane.. jmo.