at Duke University Medical Center have found a possible correlation in older adults between religious practises and brain shrinkage in the hippocampus. Hippocampal volume has been linked to depression, dementia and Alzheimer's Disease.
The article published in the March 30 of PLoS One
focused on the volume of the hippocampus using MRI scans of 268 men and women aged 58 to 84. Lead researcher Amy Owen and her team focused the study on religious individuals compared to non-religious individuals, then further breaking down of those individuals who had life changing religious experiences or who said they were born again.
Subjects were also interviewed about their religious group, spiritual practices, and life-changing religious experiences. The subjects were tracked for a period of two to eight years between November 1994 and January 2005. Those with concurrent diagnosis of other psychiatric or neurological illness, significant cognitive impairment, and substance abuse were excluded.
The study found that Protestants not identifying as born-again had the least hippocampus shrinkage compared to those who were born-again Protestants, Catholics, and those with no religious affiliation.
Previous studies have delved into neurological processes that involve spiritual beliefs but findings that show structural neuroanatomy have been rare.
At a certain point in life the hippocampus does begin to atrophy simply as part of the aging process. The study looked at if the pace of that process differed when religion was a factor. It has been determined in past studies that the hippocampus is potentially involved in religious beliefs and spiritual practices such as meditation and prayer.
The authors hypothesized that stress could be related to those with the greater hippocampal atrophy. It is known that stress hormones depress the volume of the hippocampus over time.
Owen stated that there are limitations to the findings in their study such as a small sample size.