It has been long-standing conventional wisdom that stress and happiness—or lack thereof—contributes to a person’s overall life expectancy. Results from the Million Women Study, however, are saying that this relationship has been vastly misunderstood. According to the researchers from the UK and Australia a person’s mood can indicate a lot of different things, but it does not directly impact their mortality rate.
The Million Women Study is a massive examination of women who were recruited between 1996 and 2001 and followed for over ten years. The study tracked numerous physical and mental health factors, two of which were mood and stress. At a follow-up at the ten-year mark, roughly four percent of the participating women, 31,531, had died. The researchers looked at the data and found that initially, a majority of the deceased women who self-rated themselves also reported as being unhappy. However, when medical causes of unhappiness were controlled for—such as diabetes, medical depression, arthritis, etc.—no correlation between mood and mortality were found.
According to the researchers, these findings show that the conventional wisdom about happiness and health is a result of people confusing cause and effect. In other words, people who are ill are generally unhappy as a result of their maladies rather than becoming ill due to unhappiness or stress. There is, however, an indirect relationship between mood and mortality. People who are unhappy, as the researchers note, may be more prone to things like alcohol, smoking, overeating, or other behaviors that definitely contribute to higher mortality rates. However, they stress that unhappiness or happiness itself does not affect outcomes.
To be clear, the study only looked at how mood directly affected mortality rates in absence of other factors. Someone who has been diagnosed with depression, for instance, is both going to be unhappy and have a higher mortality rate, but these individuals would have been excluded by the researchers due to their condition causing their mood. Happiness of the participants was also self-reported using set levels: rarely, never, sometimes, usually, or most of the time feeling happy. The vagueness of these phrases and the possibility of a self-reporting bias limit the precision of the data used. The study also only covers women and it is unknown if similar findings would exist should men be examined in a similar manner.
Should the study’s findings be corroborated, however, it would present a new way of looking at, and potentially not stressing about, occasional bouts of gloom.
Sources for Today’s Article:
Gallagher, J., “Being Unhappy or Stressed Will Not Kill, Says Study,” BBC News web site, December 10, 2015; http://www.bbc.com/news/health-35052404.
Liu, B., et al., “Does Happiness Itself Directly Affect Mortality? The Prospective UK Million Women Study,” The Lancet, 2015; doi: http://dx.doi.org/10.1016/S0140-6736 (15)01087-9.