Religion doesn't factor into preventing depression in the first place, but only helps one get better? God is a constant in all of this. Since these people believed in God before, after and during their depression then one is already getting a regular "dosage" of God? Belief in God did not change before or after treatment.
I smell a rat. A rat that says, "oh well, it is not just the presence of God alone but God plus"
To whit, religion only works because you are also taking anti-depressants, taking group therapy or paying lots of money to a quack.
Religion and drugs. Surprise, surprise surprise.
This sounds like the perfect premise for a Phillip K. Dick sci-fi book: take the conclusion of this article and have a book plot where preacher starts disseminating drugs as part of church service. "Scientific studies show that religion works best when coupled with anti-depressant drugs! Here, have a Xanax!"
Sad part is that this may actually come to pass.