Religion, spirituality and depression in prospective studies: A systematic review

Many empirical studies have shown inverse associations between measures of religiousness and spirituality (R/S) and depression. Although the majority of these studies is cross-sectional, a considerable number of prospective studies have also appeared.

The current systematic review offers an overview of the major pattern of associations between the measures of R/S and depression / depressive symptoms in 152 prospective studies (until 2017).

With on average two R/S measures per study (excluding measures of religious struggle, treated separately), 49% reported at least one significant association between R/S and better course of depression, 41% showed a non-significant association, and 10% indicated an association with more depression or mixed results. The estimated strength of these associations was modest (d = -0.18). Of the studies that included religious struggle, 59% reported a significant association with more depression (d = +0.30). Especially among persons identified with psychiatric symptoms, R/S was significantly more often protective (d = -0.37). In younger samples and in samples of patients with medical illness, R/S was less often protective. Studies with more extensive adjustment for confounding variables showed significantly more often associations with less depression. Geographical differences in the findings were not present.

Given the huge heterogeneity of studies (samples size, duration of follow-up), the current synthesis of evidence is only exploratory.

In about half of studies, R/S predicted a significant but modest decrease in depression over time. Further inquiry into bi-directional associations between religious struggle and (clinical) depression over time seems warranted.