Stress affects people in several ways—it activates adrenaline and other hormones, the nervous system and immune system. While not all stress is harmful, and some can even be beneficial, chronic or toxic stress can contribute to health problems. “Men and women react differently to toxic stress because their brains are wired differently,” notes Bruce McEwen, Ph.D., of The Rockefeller University, * “and therefore they may be at risk for different stress-related illnesses.” For example, as a result of chronic stress, women may be more likely to experience symptoms of depression while men may be more likely to develop problems with substance use.