Since there's no question that mental health affects longevity, focus on how to preserve yours—and how to cope with trouble when it arrives. Consider these strategies:
Exercise. Being physically active enhances mental health: It boosts energy and confidence, lifting your mood for up to 12 hours later. Being active doesn't necessarily mean going to the gym or pumping iron, either. Anything that gets you moving—hula-hooping, dancing, walking the dog—has been shown to increase emotional well-being. Try yoga, for example. It may help shield against depression. In a small 2010 study, researchers found that three hour-long sessions a week boosted participants' levels of the brain chemical GABA, which typically translates into improved mood and decreased anxiety.
Join a community organization, keep up a job, or volunteer. Friedman recalls a 100-year-old man who is "still working, albeit at a reduced pace, and still very involved in the social club he joined in 1937." That's key to boosting mental health and, in turn, longevity, he says: "We've found that 'cheer up' is useless advice, and even worse is 'don't stress' or 'take it easy,'" he says. "It's clear that being conscientiously involved in meaningful work or volunteer activities will improve both your mental health and your physical health." Indeed, people who volunteer are more likely to report a greater sense of purpose and meaning in their lives, as well as less stress and depression than non-volunteers.
Get professional help if you need it. About 80 percent of people treated for depression with drugs and therapy improve, according to the National Institute of Mental Health. Antidepressant medications can also make a big difference in quality of life and emotional well-being. Still, treatment doesn't work for everyone; a mental health professional can help determine the best course of action.
Eat well. Shaping your diet the right way can boost energy, lower the risk of developing certain diseases, fuel the brain, and counteract the way stress affects your body. Certain foods, for example, affect mood—for better or worse. Earlier this year, Spanish researchers linked fast food—burgers, hot dogs, and pizza—with feelings of depression, according to a study published in Public Health Nutrition. The more fast food and junk food the study participants consumed, the stronger their blues. Dietary changes can trigger chemical and physiological changes within the brain that alter our behavior and emotions. Try lobster, oysters, clams, and other shell fish, which contain hefty amounts of selenium, a mineral that helps combat mental decline, anxiety, and depression.