The English word 'depress' entered the language around 1380, borrowed through Old French 'depresser' from Late Latin 'depressare,' a frequentative of Latin 'deprimere.' This Latin verb combines 'de-' (down) and 'premere' (to press), giving the literal meaning 'to press down.'
The earliest English uses were physical: to depress a lever, to depress a surface, to push something downward. This mechanical sense survives today in technical contexts — one depresses a button, a brake pedal, a piano key. The past participle 'depressed' in its physical sense means 'pushed below the surrounding surface,' as in a depressed fracture of the skull (where bone is pushed inward).
The psychological meaning — to make sad, to lower someone's spirits — developed in the early seventeenth century. The metaphor is deeply embodied: sadness is conceptualized as downward pressure on the self. The spirits are 'pressed down,' energy and vitality are 'lowered.' This spatial metaphor for emotion (happy is up, sad is down) is universal across human languages
The clinical term 'depression' for a psychiatric condition emerged gradually. In the eighteenth century, physicians began using 'depression' to describe states of melancholy and low vitality. By the nineteenth century it was established medical terminology, and in the twentieth century it became the standard diagnostic label, replacing older terms like 'melancholia.' Today, 'clinical depression' or 'major depressive disorder' is one of the most commonly diagnosed
The economic sense of 'depress' and 'depression' developed in the eighteenth century. Markets, wages, and trade could be 'depressed' — pushed down from their normal or expected levels. An economic depression was a period of abnormally low activity. The term achieved its most famous application in 'the Great Depression' of the 1930s. Before that era
The Latin root family is visible throughout. 'Depression' (the noun) comes from Latin 'depressio.' 'Depressant' (something that depresses, especially a drug that lowers nervous system activity) dates to the nineteenth century. 'Depressive' (adjective) emerged in the early seventeenth century. 'Antidepressant' — a twentieth-century coinage — combines the Greek prefix 'anti-' with the Latin-derived 'depressant.'
In geography, a 'depression' is an area of land lower than its surroundings — a basin, hollow, or sunken region. In meteorology, a 'depression' or 'low-pressure system' is an area where atmospheric pressure is lower than in surrounding regions. Both uses preserve the original Latin image of pressing down.
The word 'depress' belongs to one of the largest Latin verb families in English. Its siblings — 'compress' (press together), 'express' (press out), 'impress' (press into), 'oppress' (press against), 'repress' (press back), 'suppress' (press under) — all share the root 'premere' with different prefixes, each producing a distinct metaphorical meaning from the single physical concept of applying force. The prefix 'de-' (down) gives 'depress' its specific character: not pressing in any direction, but pressing downward — the direction humans universally associate with diminishment, defeat, and sorrow.