Worrying of course does not do any good to the human body, it is known. But new studies suggest that those who ruminate a lot may have higher blood pressure and heart rates, less effective immune systems, surges of stress hormones that strain the heart, more depression and perhaps even shorter life spans.
Those who often react to stress by brooding have less of a blood pressure drop overnight than people who usually let go of things, shows a new study by psychologist Brenda Key of the University of Calgary. Smaller-than-normal dips in blood pressure at night have been linked to a higher risk of dying from strokes and heart attacks, she adds.
Other research finds that dwelling on an unpleasant experience increases the release of chemicals that can weaken the immune system over time; this may hamper someone's ability to fight illness, psychologist Nicholas Christenfeld of the University of California-San Diego.Christenfeld says. Increases in the stress hormone cortisol after rumination also can hinder the immune system and contribute to cardiovascular disease, he says.
There's no proof that chronic overthinkers die sooner because of it, he says. But one new study suggests that may be the case, at least for men. The study began with more than 1,600 men ages 40 to 90. At the start, they were given personality tests. They were tracked for 17 years to see how a trait called neuroticism affected survival.
Those who score high in the neurotic trait are "worrywarts" who cope poorly with stress and tend to be highly anxious or depressed, says study leader Daniel Mroczek of Purdue University. "They don't let things roll off their backs."
Among men who were high in this trait at the start and became even more so over time, half had died 17 years after the study started. Among those who were high in neuroticism at the start but didn't increase, and the less neurotic, 75% to 85% were still alive.
The good news: "People can change," Mroczek says. "If you learn to worry or fret less, you may add time to your life."
Women are more likely than men to overthink, says psychologist Susan Nolen-Hoeksema of Yale University, who has studied rumination for years. Women brood about things that make them sad or anxious; men are more likely to stew about anger, she says.
And you don't have to be an adult to suffer bad health effects. In her latest, four-year study of adolescent girls, she found that girls prone to ruminating were more likely than the others to develop eating disorders, alcohol problems and depression. Future chronic ruminators often were anxious little kids, Nolen-Hoeksema says.
Karen Mead, 62, of St. Paul was one of those. Living with an alcoholic father, "a Jekyll and Hyde character," she constantly worried about his unpredictable moods. "I also worried so much about whether people would like me, what people would say to me and so on." Trying to quell these anxieties, she turned to alcohol herself and became an alcoholic by early adulthood.
Through treatment for her addiction, she says, she has learned to solve problems rather than brood and calls herself "a recovering ruminator." She's director of Emotions Anonymous, a nationwide 12-step program for adults with emotional problems.
Humans are the only species prone to "overthinking" that solves nothing, says Julian Thayer, a psychologist at Ohio State University. Our complex brains "have allowed us to achieve great civilizations, but they also are maladaptive," Thayer says, because people can fall into mental potholes that aren't a threat to animals.