A study published in Translational Psychiatry has found that stress literally changes your genes. Study authors believe that their work may provide a link to explain the development of chronic diseases.

Previous studies have found that severe psychological trauma is linked with methylation changes in the DNA over the long term. This study wanted to know whether the same holds true for acute stress, as in the kind experienced when a person needs to go to a job interview.

The researchers looked at the effect of stress on two genes: one for the oxytocin receptor (OXTR) and another for the brain-derived neurotrophic factor (BDNF). OXTR has been nicknamed the "love" or "trust hormone", and is the docking site for oxytocin. BDNF is important for developing brain cells.

The study tested 76 participants, all in their 60s. One group had to perform a mock interview; the other was tasked with doing math problems while someone watched them. Both of those tests are commonly used as ways to provide stress to subject participants.

Before the test, participants gave blood samples. After the test, they also gave blood samples: one 10 minutes after the test, and one an hour and a half afterwards.

The test showed that BDNF was unaffected by the test. But the OXTR gene showed methylation changes. The amount of methylation had increased, indicating that the brain had produced too few receptors.

Then, in the follow-up blood sample an hour and a half after the test, methylation of the gene had fallen to levels lower than those seen below the test, indicating that the brain had produced too many receptors.

The authors believe that those results indicate differences in the composition of blood cells.

Dr. Gunther Meinlschmidt, a professor at the Ruhr-Universität Bochumm, said that the results may indicate a link between epigenetic changes caused by stress and chronic diseases.