Spirituality, Religion and Resilience to Depression
A new report in JAMA Psychiatry by Lisa Miller and colleagues from Columbia University, New York, NY, demonstrates that the importance of religion or spirituality is associated with thicker brain cortex in several brain regions.
Despite several empirical studies on this topic, our understanding of the neural substrates of religiosity and spirituality remain little understood.
The same authors previously reported a 90% decreased risk, assessed prospectively for 10 years, of developing major depressive disorder (MDD) in adult offspring of depressed probands (high familial risk [HR]) who said that religion or spirituality was highly important to them.
In this study these authors report that high importance of religion or spirituality was associated with thicker cortices throughout the superior parietal and occipital lobes of the brain, especially in the brain regions where a thinner cortex was found to be a morphologic endophenotype of familial risk for MDD.
According to the study’s authors these findings are correlational, and do not prove a causal association but indicate that the effects of importance on cortical thickness are more pronounced in individuals with high familial risk. The authors discuss that thicker cortex associated with a high importance of religion or spirituality may also be linked with resilience to the development of depressive illness.
As discussed by Lisa Miller and colleagues the finding that the cortex was thicker in those with high importance in both risk groups suggests that high importance may be related to structures in the brain that confer a relative resilience against developing depression. The thicker cortices were located in the same general regions as the morphologic endophenotype, conferring familial risk for depression but much more strongly in the mirror-image locations of the risk endophenotype in regions that we previously interpreted as providing cortical reserve that compensated for the presence of cortical thinning within the risk endophenotype.
A 2017 studyindicates that a high degree of belief in the importance of religion/spirituality was associated with both a thicker cortex and a larger pial surface area in persons at high risk for familial depression. In this study, cortical thickness and surface area were measured in 106 subjects in which 57 subjects had a family history of depression.
Of note, pial surface area offers a complementary measure of cortical morphology that focuses on cortical surface area, rather than cortical thickness. This data on cortical surface area provides a new potential biomarker of religion/spirituality importance and familial risk for depression.
Thus, this study supports previous findings of an association between religious/spiritual importance and cortical thickness in individuals at high risk for depression, and extend the findings to include an association between religious/spiritual importance and greater pial surface area. Moreover, the findings suggest these cortical changes may confer protective benefits to religious/spiritual individuals at high risk for depression.
In contrast to previous imaging studies that investigated the roles and functions of various cortical regions in the gray matter in relation to religious beliefs,
a 2019 study investigated white matter microstructure and integrity in relation to religious belief and correlated this with different levels of familial risk for development of MDD.
The study’s findings suggest that the reported high importance of religious/spiritual beliefs may have effects on white matter integrity in the bilateral frontal lobe, temporal lobe, and parietal lobe, particularly the bilateral precuneus. While these regions are also associated with risk of developing MDD, reorganization of white matter through religious/spiritual may help protect individuals from going on to develop the illness.
The authors of this study suggest that compared to those at low familial risk for MDD, individuals at high familial risk for MDD show significant white matter microstructural changes in white matter tracts adjacent to brain regions implicated familial risk for developing MDD.