Condition

Depression

Also Known As Major Depressive Disorder; Clinical Depression

Mental and Behavioural Disorders

Depression is a common mental disorder marked by a depressed mood or loss of interest and pleasure in daily activities, persisting most of the day, nearly every day, for at least two weeks, and arising from a complex interaction of social, psychological and biological factors rather than a single cause. Ancient Greek medicine described a related but broader condition, melancholia, from melas, black, and khole, bile, attributing it to an excess of one of the body's four humors; Hippocrates described it in his Aphorisms as fears and despondencies that, when they last a long time, mark the disease, and the humoral theory of its cause persisted through Galen and into the early modern period. The word depression entered general English usage in the seventeenth century as a term for low spirits, but its first specifically psychiatric clinical use is credited to French psychiatrist Louis Delasiauve in 1856; the term did not fully replace melancholia as the standard medical name for the condition until the end of the nineteenth century. The World Health Organization estimates that 5.7 percent of adults worldwide have depression, 4.6 percent of men and 6.9 percent of women, rising to 5.9 percent among adults aged 70 and older and to more than 10 percent among pregnant women and women who have just given birth; suicide, to which depression is a major contributor, killed an estimated 727,000 people in 2021 and is the third leading cause of death among 15 to 29 year olds worldwide.

Facts

Condition Class

chronic, psychiatric, mood disorder 4

First Described

1856 4

1856 marks French psychiatrist Louis Delasiauve first specifically psychiatric clinical use of the word depression; the broader concept of melancholia is ancient but carries no fixed year.

First Described (Era)

Ancient Greek medicine described melancholia, from melas, black, and khole, bile, as a distinct condition caused by an excess of black bile; Hippocrates described it in his Aphorisms as fears and despondencies that mark the disease when they last a long time. 4

Prevalence

The World Health Organization estimates that 5.7 percent of adults worldwide have depression, 4.6 percent of men and 6.9 percent of women, rising to 5.9 percent among adults aged 70 and older; suicide killed an estimated 727,000 people in 2021 and is the third leading cause of death among 15 to 29 year olds worldwide. 3

Classification

Body System

Nervous System 1

ICD-10 Chapter

V: Mental and Behavioural Disorders 2

Communicable or Non-communicable

Non-Communicable 3

Learn More

From Black Bile to a Clinical Word

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.

The Two Weeks That Make a Diagnosis

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.

FAQs

Why was depression once called melancholia?

Because the Greeks blamed an excess of black bile; the psychiatric term depression dates from 1856.

Ancient Greek medicine described a related condition as melancholia, from melas, black, and khole, bile, and attributed it to an excess of one of the body's four humors. Hippocrates wrote in his Aphorisms of fears and despondencies that, when they last a long time, mark the disease. The humoral explanation persisted through Galen and into the early modern period. The word depression entered general English in the seventeenth century for low spirits, its first specifically psychiatric use is credited to Louis Delasiauve in 1856, and it did not fully replace melancholia as the standard medical name until the end of the nineteenth century.

How common is depression worldwide?

About 5.7 percent of adults worldwide according to the World Health Organization.

The World Health Organization estimates that 5.7 percent of adults worldwide have depression, 4.6 percent of men and 6.9 percent of women. The share rises to 5.9 percent among adults aged 70 and older and to more than 10 percent among pregnant women and women who have just given birth.

Connections