'anti-cathartic' is formed from the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'cathartic' (from Greek 'kathartikos' relating to 'katharsis', meaning 'purging' or 'cleansing').

'cathartic' originates from Greek 'katharsis' via Latin and later Middle English/French usage; the modern adjective 'cathartic' developed from these earlier forms, and 'anti-' was attached in modern English to indicate opposition, producing 'anti-cathartic.'

Originally 'katharsis' referred to physical or ritual purification (a 'purging'); over time 'cathartic' broadened to emotional/psychological purification, while 'anti-cathartic' has come to mean opposing that emotional release.