1775, "acting upon or stimulating the nerves," from Greek neuron "nerve" (see neuro-) + -otic, as in hypnotic. Also compare neurosis. Meaning "relating to the nervous system" is by 1873. Sense of "affected by or prone to neurosis" is by 1887. The noun meaning "a neurotic person" is from 1896; earlier it meant "a drug acting on the nerves" (1660s). Related: Neurotically.
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.
<a href="https://www.etymonline.com/word/neuroticism">Etymology of neuroticism by etymonline</a>
Harper, D. (n.d.). Etymology of neuroticism. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/neuroticism