I think it is sort of for some people...in other words, people who think that faith is real, that must be a form of mental illness. People who believe in psychics and magic are in that category. But there are a lot of religious people that don't actually believe, they just want to be a part of something, or they have family history or they like or need the community. I guess you could call them liars if they keep saying they believe, but to them it's just their life and not everybody needs to be honest about how they really feel, what they really believe.

None of us are 100% mentally sound. Religion is just one way among many that one can be further impaired. I would regard most fundamentalists to be neurotic and mildly deluded, since they can hold down jobs and basically function without running afoul of the law and so forth. A minority of them are deeply deluded and suffering from personality disorders that are exacerbated rather than helped by their religious ideation. Some of course are mentally ill but I submit they would have been anyway. The most you can fairly say is they might not be quite as bad if they weren't religious. But a schizophrenic is a schizophrenic is a schizophrenic, Christian or not. I know firsthand: my first wife was a Christian schizophrenic. The latter predated the former.

The question of whether religion pushes some over the brink is a little subjective. I've no doubt it happens, but it always begs the question whether something else would have served just as well.

I've been saying for years that religious faith is a mental illness.

So true, I watched it happen with my mother.