schizophrenic adj.

1909, a broad term for a range of more or less severe mental disorders involving a breakdown of the relation between thought, emotion, and action; literally "a splitting of the mind," from German Schizophrenie (1908), coined by Swiss psychiatrist Eugen Bleuler (1857-1939), from Latinized form of Greek skhizein "to split" (from PIE root *skei- "to cut, split") + phrēn (genitive phrenos) "heart, mind" (hence phrenes "wits, sanity"), for which see phreno-.

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.

1945, "person having schizophrenia," a slang shortening of schizophrenic. As an adjective by 1957. Alternative form schiz is by 1955 as a noun, 1960 as an adjective.