The importance of religion or spirituality to a person appears to be associated with the thickness of certain brain regions, according to a study by Lisa Miller, Ph.D., of Columbia University, New York, and colleagues.

Researchers conducted a familial study of 103 adults (ages 18-54 years) who were the second- or third-generation offspring of depressed or nondepressed study participants. Religious or spiritual importance and church attendance were assessed twice over five years. The cortical thickness of the brain was measured with magnetic resonance imaging at the second time point.

Study findings indicate that importance of religion or spirituality, but not the frequency of church attendance, was associated with thicker cortices in some regions of the brain, independent of familial risk for depression. Also, the effects of the importance of religion or spirituality on cortical thickness were stronger in the group at high familial risk for depression than in the low-risk group, especially in a brain region where a thinner cortex may be associated with a familial risk for developing depressive illness.

Although a high frequency of attendance at religious services was associated with a high personal importance of religion or spirituality, the association between attendance and cortical thickness was not significant, according to the study.

"We note that these findings are correlational and therefore do not prove a causal association between importance and cortical thickness," the authors conclude.