Happiness and unhappiness have no direct effect on mortality

A study of a million UK women, published today in  The Lancet ,  has shown that happiness itself has no direct effect on mortality, and that the widespread but mistaken belief that unhappiness and stress directly cause ill health came from studies that had simply confused cause and effect. Life-threatening poor health can cause unhappiness, and for this reason unhappiness is associated with increased mortality. In addition, smokers tend to be unhappier than non-smokers. However, after taking account of previous ill health, smoking, and other lifestyle and socio-economic factors, the investigators found that unhappiness itself was no longer associated with increased mortality. The lead author, Dr Bette Liu , now at the University of New South Wales, Australia said: 'Illness makes you unhappy, but unhappiness 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.' The investigation was conducted within the UK Million Women Study. 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.