"Schizophrenie" was coined by E. Bleuer in 1910, as published in the Psychiatrisch-Neurol. Wochenschr. XII. 171).
He thought it was a clever formation, from the Greek 'phren', literally 'midriff', but figuratively 'mind', and 'schizo-', comb. form, with the -ia suffix.
In psychology, it is defined as a mental disorder occurring in various forms, all characterised by a breakdown in the relation between
b. feelings, and
usually with a withdrawal from social activity and the occurrence of delusions and hallucinations.