Major Psychological Theories and Techniques

1. Overview & Epidemiology

Psychotherapy = treatment of mental illness / behavioural disturbance in which a trained professional establishes a professional contract with the patient and, through verbal and non-verbal therapeutic communication, alleviates emotional disturbance, changes maladaptive behaviour, and encourages personality growth. Distinguished from somatic therapies (drugs, ECT).
The "who developed what" map (this topic's #1 exam trap — PSY-1.7):

Person	Contribution
Emil Kraepelin	Coined dementia praecox (early term for schizophrenia); founded descriptive nosology
Sigmund Freud	Psychoanalysis; unconscious, structural model, transference & countertransference
Carl Gustav Jung	Analytical psychology; the collective unconscious, archetypes
Alfred Adler	Individual psychology; inferiority complex, striving for superiority
Carl Rogers	Client-/person-centered therapy; the core conditions
Aaron T. Beck	Cognitive theory & therapy of depression (cognitive triad)
Ugo Cerletti (with Lucio Bini, Rome 1938)	Performed the first ECT
Avshalom Caspi	First described gene–environment interaction in depression (5-HTTLPR × life stress)

Three phases of every psychotherapy (UD lecture): (1) pre-therapy → ends with signing the therapy contract; (2) working phase; (3) conclusion (consolidate skills + relapse prevention). Note: 15–17% never attend the first session and a further 26–30% drop out after session 1–2.
Typical number of sessions (UD lecture — examiner favourite):

Modality	Sessions
Behaviour therapy	1–7
Cognitive-behavioural therapy	~20
Psychodynamic psychotherapy	20–100
Psychoanalysis	400–1000 (3–5×/week over years)