"What doesn't kill you makes you stronger" is a nice saying, but it sure doesn't always feel true — stressful events take their toll, and it can be difficult to understand how exactly any growth is supposed to result from them. As it turns out, how well you respond to stress is genetic — so stop beating yourself up over having a harder time dealing with life circumstances than other people you know. More resilient people may have just been dealt a better stress-related genetic hand than you were.
Researchers in psychiatry and psychotherapy at the Medical University of Vienna, Austria investigated individual differences in responses to stress by conducting MRI scans of study participants' brains. In some participants — those with any of three genes linked to depression — certain stressful life events (like unemployment and deaths in the family) were associated with reduced size of an important brain structure, the hippocampus. In participants without the depression genes, stressful life events seemed to increase the size of the hippocampus.
Because the hippocampus is targeted by the body's stress hormones and changes flexibly according to its exposure, these size differences amongst the participants are meaningful. The very same types of stressful life events are interpreted by the hippocampus as distress in people with one genetic makeup, and as eustress (good stress) in people with another genetic makeup. Once the hippocampus is enlarged and healthy, or shrunken and reactive, it may be set in some kind of feedback loop — where future events continue to be interpreted as ultimately beneficial, or very threatening.
Combine this with prior findings that stress negatively affects how our genes are expressed, and it's not a pretty picture. Whether you have stress-resilient or stress-susceptible DNA, the stressful conditions you face are likely to activate genes that cause inflammation in your body and diminish the capacities of your immune system. These factors are associated with worse health as a result of stress, especially in the long run (as from chronic stressors, like a toxic relationship or crummy job).
No matter how bad your genes are, though, you can do things to better support yourself through difficult (and ordinary) times. Getting enough sleep, eating well, and incorporating some exercise into your daily routine can go a long way towards regaining and maintaining your health. If your stress levels are chronically high, you need to consider taking steps to eliminate the problem, even if it means ending a relationship or finding a new job. Your genes may contribute to how stress affects you, but so do your voluntary choices — so make them good ones.