The founder of psychoanalysis appears as a holodeck recreation in Phantasms, where Data asks him to interpret a series of disturbing nightmares produced by his dream programme.
Sigmund Freud, the Viennese physician who founded psychoanalysis, appears as a hologram in the Next Generation episode Phantasms, played by Bernard Kates.
When Data's dream programme begins producing violent and bizarre nightmares, he seeks out a simulation of Freud on the holodeck and lies on the couch to describe them. Freud confidently reads the images in terms of mothers, repressed desire and a fear of Data's own destructive potential. Deanna Troi later gently suggests that Freud's ideas are of limited use for an android.
A figure of Freud also turns up inside one of Data's dreams. The nightmares finally prove to be Data's unconscious way of warning the crew about invisible interphasic organisms feeding on them.