Psychotherapy is the use of psychological methods, particularly when based on regular personal interaction, to help a person change and overcome problems in desired ways. Psychotherapy aims to improve an individual's well-being and mental health, to resolve or mitigate troublesome behaviors, beliefs, compulsions, thoughts, or emotions, and to improve relationships and social skills. Certain psychotherapies are considered evidence-based for treating some diagnosed mental disorders.
There are over a thousand different psychotherapy techniques, some being minor variations, while others are based on very different conceptions of psychology, ethics (how to live) or techniques. Most involve one-to-one sessions, between client and therapist, but some are conducted with groups, including families. Psychotherapists may be mental health professionals such as psychiatrists or psychologists, or come from a variety of other backgrounds, and depending on the jurisdiction may be legally regulated, voluntarily regulated or unregulated (and the term itself may be protected or not).
The term is derived from Ancient Greek ( meaning "breath; spirit; soul") and therapeia ( "healing; medical treatment"). The Oxford English Dictionary defines it now as "The treatment of disorders of the mind or personality by psychological methods..."
The American Psychological Association adopted a resolution on the effectiveness of psychotherapy in 2012 based on a definition developed by John C. Norcross: "Psychotherapy is the informed and intentional application of clinical methods and interpersonal stances derived from established psychological principles for the purpose of assisting people to modify their behaviors, cognitions, emotions, and/or other personal characteristics in directions that the participants deem desirable". Influential editions of a work by psychiatrist Jerome Frank defined psychotherapy as a healing relationship using socially authorized methods in a series of contacts primarily involving words, acts and rituals—regarded as forms of persuasion and rhetoric.