Middle age is truly miserable, according to a study using data from 80 countries showing that depression is most common among men and women in their forties.
The British and US researchers found that happiness for people ranging from Albania to Zimbabwe follows a U-shaped curve where life begins cheerful before turning tough during middle age and then returning to the joys of youth in the golden years.
Previous studies have shown that psychological well-being remained flat throughout life but the new findings to be published in the journal Social Science & Medicinesuggest we are in for a topsy-turvy emotional ride.
"In a remarkably regular way throughout the world people slide down a U-shaped level of happiness and mental health throughout their lives," Andrew Oswald at Warwick University, who co-led the study, said on Tuesday.
The researchers analysed data on depression, anxiety levels and general mental health and well-being taken from some 2 million people in 80 countries.
For men and women the probability of depression slowly builds and then peaks when people are in their forties - a similar pattern found in 72 countries ranging from Albania to Zimbabwe, the researchers said.
About eight nations - mostly in the developing world - did not follow the U-shaped pattern for happiness levels, Oswald and his colleague David Blanchflower of Dartmouth College in the United States wrote.