Neanderthal DNA linked to depression

A study says a person’s risk of becoming depressed or hooked on smoking may be influenced by DNA inherited from Neanderthals.

Researchers found evidence that one bit of Neanderthal DNA can boost the risk of tobacco addiction, while others can slightly raise or lower the risk of being diagnosed with depression.

It is the latest in a series of studies of the Neanderthal genetic heritage in modern people.

Neanderthals and modern humans split off from each other on the evolutionary tree hundreds of thousands of years ago. However, ancestors of modern people interbred with Neanderthals about 50,000 years ago after leaving Africa. So in people of Asian or European ancestry, around 2% of DNA can be traced to Neanderthals.

Studying that DNA might help give insights into the biological roots of some diseases, said Tony Capra, an evolutionary geneticist at Vanderbilt University. He is senior author of the study, which was released by the journal Science.

The DNA linked to depression or tobacco addiction affects risk, and does not produce those conditions by itself.

The researchers focused on bits of Neanderthal DNA that had been identified in prior research.

They looked for effects from about 1,500 of them in medical records of some 28,000 Americans of European ancestry, for whom they had genetic information.

One analysis supported a previously suggested influence on the risk of depression, with some DNA bits raising the risk and others lowering it. Overall, the analysis found, this DNA affected the risk by about 1%.