Psychotherapy is a method of treatment with psychological means (the “talking therapy“). In medicine, it is one of the legitimate therapeutic methods used in the treatment of mental disorders. There are several types of therapy nowadays, I am familiar with the psychodynamic attitudes of gestalt and psychoanalytic psychotherapy.
The indications of psychotherapy are quite broad. For some disorders, it is recommended as a first choice of treatment (e.g. light to moderate depression or anxious disorders, eating disorders, adjustment and stress-related disorders, somatoform disorders, personality issues, preschool children..).
In others, it can be useful in combination with pharmacotherapy (e.g. severe depressions, psychotic disorders). This is also a case of supportive psychotherapy in the area of somatic medicine (e.g. psychosomatic disorders), where the psychotherapy takes part in the complex treatment programs.