Have you ever wondered why some people you know crumple when faced with a stressful situation, while others appear invigorated by it? Opinions differ on the old saying “Whatever doesn’t kill you makes you stronger,” and for good reason: A new MRI brain study suggests genetics play a large role in human responses to stressful events. The study, entitled Additive Gene-Environment Effects on Hippocampal Structure in Healthy Humans, was carried out by the Medical University of Vienna and published in the Journal of Neuroscience.
“These results are important for understanding neurobiological processes in stress-associated illnesses such as depression and post-traumatic stress disorder,” said Lukas Pezawas, leader of the study. “It is ultimately our genes that determine whether stress makes us psychologically unwell or whether it encourages our mental health.”
The researchers performed MRI brain scans focusing on the hippocampus specifically. The hippocampus is the brain’s main stress-processing station, and it is known to shrink when in immediate physical danger (distress) and expand during positively stressful situations, such as making a speech or asking someone on a date. Interestingly, studies have shown that patients struggling with depression or PTSD have lower than average hippocampal volume.
The researchers looked at 153 participants’ life stressors, in addition to a DNA extraction and the MRI brain scan. The DNA was examined for three specific genes seen to be risk-factors in stress and anxiety responses. “People with the three gene versions believed to encourage depression had a smaller hippocampus than those with fewer or none of those gene versions, even though they had the same number of stressful life events,” Pezawas said.
This isn’t necessarily bad news for people with a family history of depression. Cultivating a positive attitude, exercising, and eating a nutritious diet will go a long way to help keep stress at bay. Simply the awareness that you are genetically predisposed to struggle in stressful situations may ease the burden, too.