*I think the more interesting question should be: do depressed people tend to be more secular or atheistic?
I, for one, have always been a terrible pessimist, and have been subjected to terrible, ongoing bad moods ever since I can remember. The first thing that crossed my mind when I started dabbling with atheism and critical thinking is: “Why SHOULD there be a God? I imagine this world sucks bad enough so that it doesn’t need him”.
The ability to deconvert hinges not only on education, but also on disposition. The species of atheist I’m acquainted with has a convoluted personality, and that often includes mood swings. There’s probably all kinds of atheists out there, but maybe I’ve caught some sort of trend here.
Depression can often result from a large gap between expectations and reality – expectations that might not necessarily be irrational. Presumably, it’s possible to conjecture happy-go-luckies who deceive themselves regarding their own competence as a defense mechanism against depression.
Maybe there IS some correlation between depression and rationalism, since it is obviously horrifying to impartially observe how trivial our personal existence truly is. As a by product of rationality, we understand how magnificent the universe is, and how dubious are supernatural claims. As a rather glum atheist, I find it very easy to ignore the emotional appeal to trust in the words of men and their stories about God and the supernatural – but this goes hand in hand with my inability to trust people in general, particularly when they tell me wonderful stories about some invisible sky daddy who loves me so much.
I’ve always wanted to see hard evidence, often more than is necessary, before I could truly trust what I hear and see.
I can only testify in my case that this leads me to an evidence-based worldview. Since I truly believe that it is what makes people happy that eventually drives them, I’m fully aware that worldviews change accordingly. It would be impossible for me to believe in a god or gods with my current personality, no matter what I’m offered – but it is possible for me to be irrational.
Admittedly, as irrational as any theist can be.