in the classical psychoanalytic theory of Sigmund Freud, the development of a symptom to replace one that has cleared up as a result of treatment. It is said to occur if the unconscious impulses and conflicts responsible for the original symptom are not dealt with effectively. Symptom substitution is often used as an argument against therapies aimed at symptom removal alone, as in behavior therapy and some forms of hypnotherapy; however, this argument has not been validated.