Feeling depressed? Get dirty

EMORY (US) — Disruptions in ancient relationships with healthy microorganisms in soil, food, and the gut may be contributing to the increasing rates of people suffering from depression.

A new study published in Archives of General Psychiatry, finds that the modern world has become so clean, that people are being deprived of the bacteria immune systems have come to rely on over long ages to keep inflammation at bay.

“We have known for a long time that people with depression, even those who are not sick, have higher levels of inflammation,” says Charles Raison, associate professor of psychiatry and behavioral sciences at Emory University.

“Since ancient times benign microorganisms, sometimes referred to as “old friends,” have taught the immune system how to tolerate other harmless microorganisms, and in the process, reduce inflammatory responses that have been linked to the development of most modern illnesses, from cancer to depression.”

Experiments are currently being conducted to test the efficacy of treatments that use properties of these “old friends” to improve emotional tolerance.

“If the exposure to administration of the “old friends” improves depression,” the study says, “the important question of whether we should encourage measured re-exposure to benign environmental microorganisms will not be far behind.”

Researchers from the University of Colorado and University College London contributed to the study.

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