Normal aging can cause mild cerebral volume loss, according to Alzforum. Cerebral volume loss can also be a sign of developing dementia or Alzheimer's disease, or it may result from conditions experts are not able to detect as of 2015. Religious belief may cause atrophy of the hippocampus, according to Scientific American.
All parts of the brain lose volume as the person ages, according to the Postgraduate Medical Journal. These changes range from the very molecules of the brain to its blood vessels and gray and white matter. The shrinkage is greatest in the frontal cortex. The volume or weight of the brain diminishes 5 percent each decade after a person is 40 years old and possibly accelerates after age 70.
In Alzheimer's disease, the loss of volume in the brain is dramatic, according to Alzheimer's Association. The loss is especially notable in the hippocampus, which regulates memory and emotion. The cortex of the brain shrinks, but the ventricles, which are fluid-filled lacunae in the brain, grow. Enlarged brain ventricles are also a sign of cerebrovascular disease, says Alzforum. People at low risk for dementia tended to have brain atrophy in the default-mode network. This is a network of areas in the brain that are most active when a person is at rest.
The atrophy in the hippocampus seen among religious people may be the result of stress, says Scientific American. These people, many of whom identify as born-again Christians, underwent profound religious experiences; however, people who were irreligious also had hippocampal atrophy.