the.com/antidepressant

means A medication prescribed to relieve or prevent depression, typically by adjusting levels of neurotransmitters like serotonin, norepinephrine, or dopamine in the brain.

from Straightforward Latin-via-English construction: the prefix 'anti-' (against, from Greek anti) bolted onto 'depressant,' itself from Latin deprimere — 'to press down.' 'Depression' had already drifted from describing sunken ground or low barometric pressure to naming a sunken mood by the 19th century, so once chemists started making mood-lifting compounds in the mid-20th century, 'antidepressant' was the obvious, almost lazy label — the thing that presses back against the thing that presses you down.