Impact of stress on emotions linked to genes

The genetic conditions of each individual person determine what effect stress has on their emotions, researchers from the Medical University of Vienna in Austria have claimed in a new study.
The fact that people react differently to identical stressful life events, such as some managing to persevere while others break down and even fall ill, is determined by a complex interplay in depression gene variants along with external environmental factors, the University said Monday, according to an Austria Press Agency report.
The Viennese research team in conjunction with international partners found the hippocampus in the brain, a switching station that processes emotions and is a central interface in the stress process, would lose volume over the long term when confronted with stress, which it interprets as distress.
This was visible in depressed patients and accounts for some of their clinical symptoms. On the other hand it was observed that positive forms of stress (eustress) as can occur in emotionally stimulating social situations were capable of leading to an increase in the volume of the hippocampus.
People with genes that predispose them to a higher likelihood of depression perceive various life events such as deaths in the family, divorce, and job loss more negatively and thus negatively affects the volume of their hippocampus.
Those with very few or none of these genes may even perceive the same life event in a positive light, and overall maintain a larger-volume hippocampus, the researchers said.
Study leader Luke Pezawas said the research highlighted the importance of gene-environment interactions as determining hippocampus volume.
He added the results are important in understanding neurobiological processes involved in stress-related diseases such as depression or post-traumatic stress disorder.