'non-cathartic' is formed by the prefix 'non-' (from Latin 'non', meaning 'not') combined with 'cathartic'. 'Cathartic' originates from Greek 'kathartikos', from 'kathairein' meaning 'to cleanse'.

'cathartic' comes from Greek 'kathartikos' → Late Latin/Medieval Latin 'catharticus' → French 'cathartique' → Middle/Modern English 'cathartic'. The modern compound 'non-cathartic' is an English negative formation using the prefix 'non-' attached to 'cathartic'.

Originally related to physical or ritual 'cleansing' ('to cleanse'), the sense broadened to include psychological/emotional release; 'non-cathartic' therefore denotes absence of those cleansing or release effects.