Adjective-forming suffix — “pertaining to (a named condition or structure)” — adjectival counterpart to the noun-forming suffix -osis
The suffix entered English in the 1820s as neurotic (adjective), borrowed from Modern Latin neuroticus, from Greek νευρωτικός (neurotikos) — literally “pertaining to the nerves” (neuron + -ōtikos “pertaining to”). The adjective psychotic appeared in the 1900s, and nephrotic in the 1920s. The suffix -ōtikos (“pertaining to”) connects -otic to the entire adjective-forming suffixes: neurotic (neuro- + -otic → pertaining to the nerves/a neurosis), psychotic (psycho- + -otic → pertaining to the mind/a psychosis), and nephrotic (nephr- + -otic → pertaining to the kidneys/a nephrosis). The adjective-forming suffix-otic is productive in neurology, psychiatry, nephrology, and dentistry: e.g., odotontic, corticotropic (cf. -otic), hepatic (cf. -ic variant), and pulmonic (cf. -ic variant).