A new study claims that unhappiness is not the direct cause of increased mortality and ill health; rather, it is ill health that makes us unhappy.
The study, published in The Lancet, was led by Dr. Bette Liu of the University of South Wales in Australia.
Dr Liu and colleagues came to their findings by conducting an analysis of 719,671 women who included in the UK’s Million Women Study.
An average age of 59 years, the women were enlisted into the study between 1996 and 2001. Three years after their recruitment, they were requested to complete a questionnaire detailing their feelings of relaxation, control, happiness and stress, as well as their health.
About 39% of the women stated that they were happy the majority of the time, 44% reported that they were usually happy, and 17% stated that they were unhappy.
Over the next decade, 31,531 of the women died. The team examined analyzed mortality incidence from all causes such as heart disease and cancer.
The researchers found that the women who were already in poor health at the beginning of the study were most probable going to report being stressed, not relaxed, not in control and having feelings of unhappiness.
Mirroring results of prior studies, women who had feelings of unhappiness were more likely to be of low socioeconomic status, to smoke, have low physical activity and not live with a partner.
Controlling for already existing differences in lifestyle and health, the research team found that the rates of all-cause mortality, cancer mortality and heart disease mortality over the decade-long follow up were the same between both unhappy and happy women.
The authors wrote that after adjustment for these factors, no strong proof remains that stress or unhappiness increase mortality or that being in control, relaxed or happy reduces mortality.
The authors state that prior studies linking unhappiness with increased mortality or happiness with reduced mortality have not taken into account how ill health affects a person’s happiness or feelings of stress.