depress has 9 distinct synonyms spread across 3 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is elate.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
lower someone's spirits; make downhearted
“These news depressed her”
lower (prices or markets)
“The glut of oil depressed gas prices”
lessen the activity or force of
“The rising inflation depressed the economy”
Synonyms, antonyms and the broader and narrower relations for depress come from Princeton University’s WordNet. Full sources and licences.