Two intensive, long0term studies in rural counties (one in Sweden, one in Canada) signed up people born between the 1870s and the 1990s and tracked them from the middle to the late 20th century, embracing staggered lives that spanned more than a century. Neither found signs of a long-term rise in depression.

Steven Pinker, Enlightenment now: the case for reason, science, humanism, and progress, New York, 2018, p. 282