From Scientific American:
Closing in on 40? 50? Feel like life is passing, er, has passed you by? Maybe even left you in the dust? You’re not alone. In fact, new research shows that fellow midlifers throughout the world–or at least a significant chunk of it–share your pain. But fear not: if you endure, the study shows, things will begin looking up again, once you get over that speed bump in the road of life called (gasp!) middle age. Researchers from Dartmouth College in Hanover, N.H., and the University of Warwick in Coventry, England, after scouring 35 years worth of data on two million people from 80 nations, have concluded that there is, indeed, a consistent pattern in depression and happiness levels that is age-related and leaves us most blue during midlife.
According to the study, set to be published in the journal Social Science & Medicine, happiness follows a U-shaped curve: It is highest at the beginning and end of our lives and lowest in-between. The researchers found that the peak of depression for both men and women in the U.K. is around 44 years of age; in the U.S., women on average are most miserable at age 40 whereas men are when they hit 50. They found a similar pattern in 70 other countries. So what’s at the root of this depressing dip? Not sure, say authors Andrew Oswald of Warwick University and Dartmouth’s David Blanchflower, both economists. But they speculate, as Oswald put it, that “something happens deep inside humans” to bring us down rather than shattering events (such as divorce or job loss), because it tends to creep up on us over time.
More here.