«Indeed, the choice of a career in psychotherapy has sometimes been a way of solving the therapist’s personal problems. Some members of the early generations of psychotherapists, especially in the psychoanalytic tradition, clearly had troubled lives (Maeder 1989). This gave rise to the quip that one doesn’t have to be crazy to be a psychiatrist — but it helps. Personal vulnerability may motivate and enable a person to heal others, an insight embodied in the Greek myth of the centaur Chiron: Chiron, the teacher of Aesculapius, suffered from a wound that never healed. We may recall that some shamans are or have been mentally ill. A person’s own wounds may enhance the ability to empathize with the sufferings of others. In addition, the healer who has been cured may serve as a model and a source of hope to the sufferer.

The therapist’s personal suffering, however, is not inevitably helpful; troubled therapists have been known to exploit patients in the service of their own needs, with predictably disastrous results. Nor is there any evidence that psychotherapists who have undergone therapy themselves are more successful than those who have not (Greenberg and Staller 1981).»

— Jerome D. Frank MD PhD. Persuasion and Healing: A Comparative Study of Psychotherapy