noun
A formal or clinical term for a depressed state of mind. In everyday conversation, 落ち込み or 憂うつ are more common.
長期間の抑鬱状態が続くと、専門家に相談したほうがいい。
If a prolonged state of depression continues, it's better to consult a specialist.
彼は抑鬱の症状を訴えて病院に行った。
He went to the hospital complaining of symptoms of depression.
Compound of 抑 (suppress) and 鬱 (gloom, depression). The kanji 鬱 is notoriously complex, leading to the common simplified spelling 抑うつ.