There's no evidence it's lower. If anything I'd expect it to be higher, because at bottom, Christianity IS a suicide cult. They had to cobble on the suicide taboo to counter that.

Think about it: life is a veil of tears and justice and closure and comprehensibility are only certain in the afterlife. So why screw around here -- why not go straight to heaven right now? Get yourself a 30 ought six and bypass all this suffering (as well as prove your faith!). That's what Christianity would be without the suicide taboo.

Ever since Durkheim's study on suicide, it has been known that religion actually increases the likelihood of suicide.