"Long before it's in the papers"
December 11, 2015

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Happiness level found to have no direct effect on mortality

Dec. 11, 2015
Courtesy of the Lancet
and World Science staff

A study of a mil­lion U.K. wom­en has found that con­tra­ry to wide­spread be­lief, hap­pi­ness or lack of it have no di­rect ef­fect on mor­tal­ity.

“Ill­ness makes you un­hap­py—but un­hap­pi­ness it­self does­n’t make you ill,” said the stu­dy’s lead au­thor, Bette Liu, sum­ming up the find­ings. “We found no di­rect ef­fect of un­hap­pi­ness or stress on mor­tal­ity, even in a ten-year study of a mil­lion wom­en,” added Liu, who is now at the Un­ivers­ity of New South Wales in Aus­tral­ia.

The study was pub­lished Dec. 9 in the jour­nal The Lan­cet.

Life-threatening poor health can cause un­hap­pi­ness, the re­search­ers said, and smok­ers tend to be less hap­py than non-smok­ers—two rea­sons why un­hap­pi­ness and poor health can be linked. But that sta­tist­i­cal con­nec­tion van­ished af­ter tak­ing ac­count of pre­vi­ous ill health, smok­ing, and oth­er lifestyle and socio-economic fac­tors, the in­ves­ti­ga­tors said.

Three years af­ter join­ing the study 10-year, wom­en were sent a ques­tion­naire ask­ing them to rate their own 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.

As in oth­er stud­ies, un­hap­pi­ness was found to be 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, av­er­age age 59 years, and over the next 10 years these wom­en were fol­lowed by elec­tron­ic rec­ord link­age for mor­tal­ity, dur­ing which time 30,000 of the wom­en died.

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, ac­cord­ing to the au­thors. 

They added that 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 found to be true for overall mor­tal­ity, for can­cer mor­tal­ity, and for heart dis­ease mor­tal­ity, and for stress as well as for un­hap­pi­ness.


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A study of a million U.K. women has found that contrary to widespread belief, happiness or lack of it have no direct effect on mortality. “Illness makes you unhappy—but unhappiness itself doesn’t make you ill,” said the study’s lead author Bette Liu, now at the University of New South Wales in Australia, summing up the findings. “We found no direct effect of unhappiness or stress on mortality, even in a ten-year study of a million women.” The study was published Dec. 9 in the journal The Lancet. Life-threatening poor health can cause unhappiness, the researchers said, and smokers tend to be less happy than non-smokers—two reasons why unhappiness and poor health can be linked. But that link vanished after taking account of previous ill health, smoking, and other lifestyle and socio-economic factors, the investigators said. Three years after joining the study 10-year, women were sent a questionnaire asking them to rate their own 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. As in other studies, unhappiness was found to be 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, average age 59 years, and over the next 10 years these women were followed by electronic record linkage for mortality, during which time 30,000 of the women died. 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, according to the authors. They added that 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 found to be true for overall mortality, for cancer mortality, and for heart disease mortality, and for stress as well as for unhappiness.