Religious Experiences and Brain Shrinkage

Excerpt from "Religious Experiences Shrink Part of the Brain, Scientific American by Andrew Newbert. The article, “Religious factors and hippocampal atrophy in late life,” Amy Owen and colleagues at Duke University represents an important advance in our growing understanding of the relationship between the brain and religion. The study, published March 30 in PLoS One, showed greater atrophy in the hippocampus in individuals who identify with specific religious groups as well as those with no religious affiliation. It is a surprising result, given that many prior studies have shown religion to have potentially beneficial effects on brain function, anxiety and depression.

In this study, Owen et al. used MRI to measure the volume of the hippocampus, a central structure of the limbic system that is involved in emotion as well as in memory formation. They evaluated the MRIs of 268 men and women aged 58 and over, who were originally recruited for the NeuroCognitive Outcomes of Depression in the Elderly study, but who also answered several questions regarding their religious beliefs and affiliation. The study by Owen et al. is unique in that it focuses specifically on religious individuals compared to non-religious individuals. This study also broke down these individuals into those who are born again or who have had life-changing religious experiences.

The results showed significantly greater hippocampal atrophy in individuals reporting a life-changing religious experience. In addition, they found significantly greater hippocampal atrophy among born-again Protestants, Catholics and those with no religious affiliation, compared with Protestants not identifying as born-again.
The authors offer the hypothesis that the greater hippocampal atrophy in selected religious groups might be related to stress. They argue that some individuals in the religious minority, or those who struggle with their beliefs, experience higher levels of stress. This causes a release of stress hormones that are known to depress the volume of the hippocampus over time. This might also explain the fact that both non-religious as well as some religious individuals have smaller hippocampal volumes.

This new study is intriguing and important. It makes us think more about the complexity of the relationship between religion and the brain. This field of scholarship, referred to as neurotheology, can greatly advance our understanding of religion, spirituality and the brain. Continued studies of both the acute and chronic effects of religion on the brain will be highly valuable. For now, we can be certain that religion affects the brain--we just are not certain how. Full story can be found here.

CMDA Ethics Committee Chair and Academic Neurologist, William P. Cheshire, MD, MA: "Before brain scans, we evaluated other people's thoughts and beliefs by their words and actions. We came to understand our fellow human beings through the telling of stories, the sharing of struggles and the occasional smile.

"Enter the brain scan. High resolution neuroimaging can now peer into the living brain and chart neural activity corresponding to virtually any aspect of thought or behavior. Whether in illness or health, interpretations of human nature have shifted focus from the art of conversation to the science of the imaging console. In connecting these complementary perspectives, each of which is informative and valid, it is necessary to evaluate what the evidence does and does not show.

"The study by Owen et al. demonstrates interesting correlations but not causation. Whereas they hypothesize that religious experiences are stressful and therefore deleterious for hippocampal volume, they did not ask whether their subjects’ religious experiences were good or bad or if they had experienced nonreligious life stress. The lack of correlation of hippocampal volume changes with the study’s stress measure, moreover, seems to contradict their conclusion.

"Another interpretation of the data could be that individuals who endured stressful life experiences and recovered well enough to gain access to the research study were more likely to have found meaning, consolation and compassionate support through religious experience and involvement in a vibrant religious community. Similarly, if a study were to find that people with a history of illness were more likely to have visited a medical clinic, it would have to ask further questions to distinguish cause from cure.
 
"Investigations into neurotheology are worthwhile, and there is much to be learned about the spiritual aspect of the brain. While I agree with Newberg’s analysis, I find the provocative title somewhat disturbing, since it may invite stereotyping. As has always been true for instruments that measure the human cranium, we should be cautious to avoid prejudicial opinions of others based on assumptions about physical differences."