Words related to psycho

psychologist (n.)

"one who studies, writes on, or is versed in psychology," 1727; see psychology + -ist.

psychopath (n.)

1885, in the criminal psychology sense, "a morally irresponsible person," considered as mentally deranged; "one who obeys his impulses regardless of social codes," a back-formation from psychopathic.

The Daily Telegraph had, the other day, a long article commenting on a Russian woman who had murdered a little girl. A Dr. Balinsky prevailed upon the jury to give a verdict of acquittal, because she was a "psychopath." The Daily Telegraph regards this term as a new coinage, but it has been long known amongst Spiritualists, yet in another sense. [The Medium and Daybreak, Jan. 16, 1885]

The case alluded to, and Balinsky's means of procuring the acquittal, were briefly notorious in England and brought the word into currency in the modern sense.

psychological (adj.)

1680s, "of or pertaining to the mind as a subject of study;" see psychology + -ical. In early 20c. the sense gradually shifted toward "affecting or pertaining to a person's mental or emotional state." Related: Psychologically. Psychological warfare "use of propaganda, etc., to undermine an enemy's morale or resolve" is recorded from 1940. Psychological moment was in vogue from 1871, from French moment psychologique "moment of immediate expectation of something about to happen."

The original German phrase, misinterpreted by the French & imported together with its false sense into English, meant the psychic factor, the mental effect, the influence exerted by a state of mind, & not a point of time at all, das Moment in German corresponding to our momentum, not our moment. [Fowler]
psychopathic (adj.)

"pertaining to or of the nature of psychopathy," 1847, from psychopathy on model of German psychopatisch, from Greek psykhē "mind" (see psyche) + pathos "suffering" (from PIE root *kwent(h)- "to suffer").