I'm surprised that few have made reference to any studies or scientific literature. I think the general unbiased consensus is that religion tends have a net positive mental health benefit:
http://baylorisr.org/wp-content/uploads/...health.pdf
http://roa.sagepub.com/content/27/2/197.short
http://baylorisr.org/wp-content/uploads/...health.pdf
http://roa.sagepub.com/content/27/2/197.short