Know how to use "fewer" and "less"? Find out.
1776, "functional derangement arising from disorders of the nervous system," coined by Scottish physician William Cullen (1710-1790) from Greek neuron "nerve" (see neuro-) + Modern Latin -osis "abnormal condition." Used in a general psychological sense since 1871; clinical use in psychiatry dates from 1923.
neurosis neu·ro·sis (nu-rō'sĭs, nyu-)
n. pl. neu·ro·ses (-sēz)
Any of various mental or emotional disorders involving symptoms such as insecurity, anxiety, depression, and irrational fears.
Tension or irritability of the nervous system; nervousness.