Webster's Third New International Dictionary (1993) gives the following definition of psychotherapy: (1) “A treatment of mental or emotional disorder or maladjustment by psychological means especially involving verbal communication”; (2) “any alteration in an individual's interpersonal environment, relationships, or life situation brought about especially by a qualified therapist and intended to have the effect of alleviating symptoms of mental or emotional disturbance.”

Ray Corsini (2002) in his Dictionary of Psychology gives the following definition of psychotherapy: “Any systematic methodology based on some theory of personality intended to achieve desirable changes in thinking, feeling and behavior.”

Colorado law (C.R.S. 12-43-201§9) gives the following definition: “Psychotherapy” means the treatment, diagnosis, testing, assessment, or counseling in a professional relationship to assist individuals or groups to alleviate mental disorders, understand unconscious or conscious motivation, resolve emotional, relationship, or attitudinal conflicts, or modify behaviors which interfere with effective emotional, social, or intellectual functioning. Psychotherapy follows a planned procedure of intervention which takes place on a regular basis, over a period of time, or in the cases of testing, assessment, and brief psychotherapy, it can be a single intervention.”