Happiness may make the world go round but it does not make you live longer, according to new research ending the mistaken belief that being sad or stressed leads to ill-health.
A 10-year study of one million women found people’s emotional state of well-being had no direct effect on mortality and that previous research simply confused cause and effect.
Life-threatening poor health can obviously cause unhappiness, which is why unhappiness is associated with increased mortality the researchers said.
The study is so large that it rules out unhappiness being a direct cause of any material increase in overall mortality in women. This was true for overall mortality, for cancer mortality, and for heart disease mortality, and it was true for stress as well as for unhappiness.
Smoking usually made people unhappier than non-smokers, researchers found. However, after taking account of previous ill health, smoking, and other lifestyle and socio-economic factors, they found that unhappiness itself was no longer associated with increased mortality.
Co-author Professor Sir Richard Peto, of the University of Oxford, said: “Many still believe that stress or unhappiness can directly cause disease, but they are simply confusing cause and effect. Of course people who are ill tend to be unhappier than those who are well, but the UK Million Women Study shows that happiness and unhappiness do not themselves have any direct effect on death rates.”
The investigation, published in The Lancet today/on Thursday was carried out within the Million Women Study - a national study of women’s health, involving more than one million UK women aged 50 and over, and a collaborative project between Cancer Research UK and the NHS.
Three years after joining the study, women were sent a questionnaire asking them to self-rate their health, happiness, stress, feelings of control, and whether they felt relaxed. Five out of six of the women said they were generally happy, but one in six said they were generally unhappy.
Unhappiness was associated with deprivation, smoking, lack of exercise, and not living with a partner. The strongest associations, however, were that the women who were already in poor health tended to say that they were unhappy, stressed, not in control, and not relaxed.
The main analyses included 700,000 women with an average age of 59. During the next 10 years these women were followed by electronic record linkage for mortality, during which time 30,000 of them died.
The scientists said after allowing for any differences already present in health and lifestyle, the overall death rate among those who were unhappy was the same as the death rate among those who were generally happy.
Lead author, Dr Bette Liu, now at the University of New South Wales, Australia said: “Illness makes you unhappy, but unhappiness itself doesn’t make you ill. We found no direct effect of unhappiness or stress on mortality, even in a ten-year study of a million 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 effects of happiness and wellbeing on society are becoming increasingly measured and studied. David Cameron introduced The Happiness Index in 2012, measuring national well-being, while a West Midlands school became the first in the country to introduce lessons in happiness this week. All pupils at Sacred Heart Primary School in Tipton, from nursery to Year 6, will study the new subject alongside maths and English following positive responses to a training day for staff in November.
Headteacher Melanie Gee said she had been exploring a variety of ideas to make sure children’s well-being and mental health needs were being met.
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