People’s obsession with cleaning could be linked to rising rates of depression, scientists claim.
They believe that eliminating bacteria and viruses has made our immune systems weaker, and this in turn has affected the functioning of our brains.
Scientists have long blamed our overly sterile environments for increases in asthma and allergies. They say some bacteria are necessary for bolstering our immune systems, and without them our bodies over-react to dust and pollen, resulting in an allergy.
But now researchers believe that this over-reaction may also impair the brain’s ability to produce certain chemicals that make us happy – such as serotonin – and this leads to depression. They point out that rates of depression are far higher in the Western world compared to poorer nations, because people’s immune systems are less trained to cope with bacteria.
Around one in 10 Britons suffers from depression compared to just one in a 100 in Nigeria, for example.
Researchers in Atlanta, Georgia, have studied how this over-reaction, or inflammation, affects the brain by recruiting a group of 27 patients taking drugs to treat hepatitis C – which causes similar reactions.
They believe certain reactions may affect the brain’s ability to produce certain chemicals, including serotonin, known as the “happy hormone”.
Dr Andrew Miller, one of the scientists, said: “We believe the immune system is causing depression.
“As people develop and grow up, their immune system develops. If they are exposed to more bacteria and parasites, they are able to better control the inflammation.
“Nowadays people’s environment is much cleaner and hygienic so our immune system never really learns how to deal with infectious agents. We are overactive because our immune system has not been trained.”
The researchers, whose study was published in the journal Molecular Psychiatry, are now testing whether anti-inflammatory drugs could be used to treat depression. – Daily Mail