Depression is the leading cause of illness and disability in adolescence. Many studies show a correlation between religiosity and mental health, yet the question remains whether the relationship is causal. We exploit within-school variation in adolescents’ peers to deal with selection into religiosity. We find robust effects of religiosity on depression that are stronger for the most depressed. These effects are not driven by the school social context; depression spreads among close friends rather than through broader peer groups that affect religiosity. Exploration of mechanisms suggests that religiosity buffers against stressors in ways that school activities and friendships do not.The key finding:
…a one standard deviation increase in religiosity decreases the probability of being depressed by 11 percent. By comparison, increasing mother’s education from no high school degree to a high school degree or more only decreases the probability of being depressed by about 5 percent.It seems obvious to me that religious arose as a way to cope with terrible feelings: grief, rage, anxiety, depression. So it makes sense that religious people would be happier. On the other hand the effects you see in a broad societal analysis are not this big; religious adults are (from what I have read) only slightly less likely to be depressed than non-believers.
I wonder if the particular mental and emotional tasks of adolescence magnify this effect. I remember as a young teenager being really, really freaked out by the thought of my own death and non-existence, and by the thought that everyone around me would also die. Now I am not nearly so bothered by these ideas. So maybe the intense emotionality of teenage thinking about the world makes the support of faith particularly valuable.