From a neuroscience perspective, Sapolsky pointed to several exciting new areas of research. "It's becoming clear that in the hippocampus, the part of the brain most susceptible to stress hormones, you see atrophy in people with post-traumatic stress disorder and major depression," he said. "There's a ton of very exciting, very contentious work as to whether stress is causing that part of the brain to atrophy, and if so, is it reversible. Or does having a small hippocampus make you more vulnerable to stress-related traumas? There's evidence for both sides."
He also cited new studies suggesting that chronic stress causes DNA to age faster. "Over time, the ends of your chromosomes fray, and as they fray your DNA stops working as well, and eventually that could wind up doing in the cell," he said. "There are now studies showing that chromosomal DNA aging accelerates in young, healthy humans who experience something incredibly psychologically stressful. That's a huge finding."
According to Sapolsky, the most important new area of neuroscience research may be the effort to understand differences in the way individuals respond to stress. "This gets you into the realm of why do some people see stressors that other people don't, and why, in the face of something that is undeniably a stressor to everybody, do some people do so much worse than others?" he said. "Genes, no doubt, have something to do with it, but not all that much. However, there is evidence about development beginning with fetal life--prenatal stress, stress hormones from the mom getting through fetal circulation--having all sorts of long-term effects.