Depression

This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.

For roughly two thousand years, Western medicine's explanation for what we now call depression rested on a single organ system that does not, in the way the ancient Greeks imagined it, exist. Melancholia, the condition's ancient name, comes from melas, black, and khole, bile, and reflected the belief that an excess of one of the body's four humors caused a specific, describable set of symptoms. Hippocrates himself described the condition in his Aphorisms, characterizing fears and despondencies that, when they persist for a long time, mark the disease, and the theory persisted through Galen and into the early modern period essentially unchanged in its basic logic.

The word depression itself is a much later arrival to psychiatry, and its path there is oddly indirect. It entered general English in the seventeenth century simply meaning low spirits, with no clinical weight attached, and stayed a loose figure of speech for two centuries. Its first specifically psychiatric, clinical use is credited to French psychiatrist Louis Delasiauve in 1856; even then it took until the close of the nineteenth century for depression to fully displace melancholia as medicine's standard name for the condition.

This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.

Modern psychiatry defines depression with a precision the ancient humoral theory never attempted: a depressed mood or loss of interest and pleasure in daily activities that persists most of the day, nearly every day, for at least two weeks, arising from a genuinely complex mix of social, psychological and biological factors rather than a single cause anyone can point to. The World Health Organization estimates that 5.7 percent of adults worldwide live with depression, a figure that splits unevenly by sex, 4.6 percent of men against 6.9 percent of women, and rises further among specific groups: 5.9 percent of adults aged seventy and older, and more than 10 percent of pregnant women and women who have just given birth.

The condition's most severe consequence is measured separately but is closely tied to it: suicide killed an estimated 727,000 people in 2021 and remains the third leading cause of death among people aged fifteen to twenty-nine worldwide. Even in wealthy countries, treatment does not reliably follow diagnosis; the World Health Organization reports that in high-income countries only about a third of people with depression receive any mental health treatment at all, a gap this atlas records as part of the condition's history rather than a footnote to it.