Neurosis
A neurosis was a psychological disorder.
Nyota Uhura had heard that all Kzinti Telepaths were unhappy neurotics, and felt that aptly described one they met in 2269. (TAS: "The Slaver Weapon")
In 2370, upon hearing of Data's burgeoning obsession with his troublesome dreams, Deanna Troi suggested he might be developing a neurosis. This seemed to interest the android, prompting Troi to then remark that she had never had somebody come into her office excited at the idea that they had developed a new neurosis. (TNG: "Phantasms")
In 2375, Garak was disinterested in Ezri Dax's attempts to understand his and his father's relationship, assuring her he wasn't "some quivering neurotic who feels sorry for himself because his daddy wasn't nice." (DS9: "Afterimage")