Parts of the brain's outer layer, the cortex, were thicker in high-risk study participants who said religion or spirituality was "important" to them versus those who cared less about religion.
"Our beliefs and our moods are reflected in our brain and with new imaging techniques we can begin to see this," Myrna Weissman told Reuters Health.
"The brain is an extraordinary organ. It not only controls, but is controlled by our moods."Weissman, who worked on the new study, is a professor of psychiatry and epidemiology at Columbia University and chief of the Clinical-Genetic Epidemiology department at New York State Psychiatric institute.
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The study found a link between brain thickness and religiosity
While the new study suggests a link between brain thickness and religiosity or spirituality, it cannot say that thicker brain regions cause people to be religious or spiritual, Weissman and her colleagues note in JAMA Psychiatry.
It might hint, however, that religiosity can enhance the brain's resilience against depression in a very physical way, they write.
What have past studies shown?
Previously, the researchers had found that people who said they were religious or spiritual were at lower risk of depression. They also found that people at higher risk for depression had thinning cortices, compared to those with lower depression risk.
The cerebral cortex is the brain's outermost layer made of gray matter that forms the organ's characteristic folds. Certain areas of the cortex are important hubs of neural activity for processes such as sensory perception, language and emotion.
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The study
For the new study, the researchers twice asked 103 adults between the ages of 18 and 54 how important religion or spirituality was to them and how often they attended religious services over a five-year period.
In addition to being asked about spirituality, the participants' brains were imaged once to see how thick their cortices were.
All the participants were the children or grandchildren of people who participated in an earlier study about depression. Some had a family history of depression, so they were considered to be at high risk for the disorder. Others with no history served as a comparison group.
Findings of the study
Overall, the researchers found that the importance of religion or spirituality to an individual - but not church attendance - was tied to having a thicker cortex. The link was strongest among those at high risk of depression."What we're doing now is looking at the stability of it," Weissman said.
Her team is taking more images of the participants' brains to see whether the size of the cortex changes with their religiosity or spirituality."This is a way of replicating and validating the findings," she said. "That work is in process now.
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