Members of Falun Gong spiritual movement meditate at the Lafayette Park. A new study has suggested that spiritual activity such as meditation may hep prevent depression by thickening the brain cortex / AFP/Getty Images

Those who place a high level of importance on spirituality and religion were found to have thicker cortices in the areas normally associated with thinning in people at risk, than those who did not

Meditation and other such spiritual or religious practices may help prevent depression by prompting a thickening of the brain cortex, researchers have said.

Mindfulness based therapy has long been recommended to those who suffer from depression and a recent study by the same team found that spirituality can protect against the illness, particularly in those who are predisposed.

Following up on the previous findings, the researchers, led by Lisa Miller, professor and director of Clinical Psychology and director of the Spirituality Mind Body Institute at Teachers College, Columbia University, think they may have discovered why.

The new study found that those who placed a high importance in religion or spirituality had thicker cortices than those who did not.

For those with a family history of mental illness, the results were even more striking - a thicker cortex was found in precisely the same regions of the brain that has otherwise shown thinning in people at high risk of developing depression.

The paper did however caution that “these findings are correlational and therefore do not prove a causal association between importance and cortical thickness”.

Professor Miller said: “The new study links this extremely large protective benefit of spirituality or religion to previous studies which identified large expanses of cortical thinning in specific regions of the brain in adult offspring of families at high risk for major depression.”

The research involved 103 adults, at either high or low risk of depression based on family history, who were asked about how much importance they placed on religion or spirituality. Cortical thickness was then measured through brain MRI scans.