Depression and other mental illnesses may actually be a form of brain damage rather than chemical imbalances in the CNS.
Interesting quote about antideressants working better with therapy/counselling:
He compares antidepressants with anabolic steroids, which increase muscle mass only when subjects also go to the gym.
"If you just sit on your couch, then steroids aren't going to be very effective," he says. "Antidepressants are the same way: if you want the drug to work for you, then you have to work for the drug."