This news will probably make you happy—but if it doesn’t, you won’t die! A 10-year study of 1 million women in the U.K. has found that happiness does not stave off mortality and that studies linking unhappiness and stress to health problems have “simply confused cause and effect.” In other words, being sick and nearing death makes people unhappy, not the other way around. Crazy world, innit?
The data, published on Wednesday in the Lancet, was gathered as part of the UK Million Women Study. Women joined the study between 1996 and 2001; three years in, they filled out a questionnaire on their health, happiness, stress levels, and “feelings of control.” One out of every 6 women reported that they felt generally unhappy.
Unhappiness, unsurprisingly, coincided with poverty, lack of exercise, and living without a partner. The less education women achieved, the happier they were, too. But the most dramatic correlation was between unhappiness and existing health problems. When researchers controlled for previous health problems, socio-economic status, lifestyle factors, and smoking (on average, smokers are unhappier than nonsmokers), they found that, over 10 years, the death rate among women who were generally unhappy was the same as the rate for generally happy women. The enormity of the study’s sample rules out any direct link between unhappiness and mortality—including cancer mortality and heart disease mortality—in women.
“Previous reports of reduced mortality being associated with happiness, with being in control, with being relaxed, or with related measures of wellbeing had not allowed properly for the strong effect of ill health on unhappiness and on stress,” the Lancet wrote in a statement.
There are mitigating possibilities, of course. People may stop exercising or begin smoking because they’re unhappy, which would lead to poor health and increased risk of mortality. Future study is needed to parse out more causes and effects of particular illnesses. “An important gap exists in knowledge about the potential associations of happiness with the incidence of cognitive decline and dementia,” wrote the University Hospital of Toulouse’s Philipe de Souto Barreto and Yves Rolland in a comment on the study. “Indeed, happiness is associated with healthy lifestyles, such as exercise and abstinence from smoking, which, in turn, are protective factors against dementia. Therefore, it is plausible to suggest that happiness could be associated with a reduced risk of incident dementia.”
Even so, this new data is solid proof that people who are depressed, anxious, or stressed need not pile on more guilt and worry because they think they’re bringing about their own demise. In a world with enough bad news to make anyone want to curl up in a hole and read disheartening studies until the universe caves in, that’s something to smile—or at least, not die—about.