The Roots and Evolution of Ego-State Theory and Therapy.

The purpose of this article is to elucidate the origins of ego-state theory and therapy and to discuss the concept of human personality as a structure comprising numerous ego states. The historical roots of ego-state theory and therapy are reviewed. Also, the evolution of ego-state therapy from classic hypnotherapy to modern methods is identified. The article notes that these methods of ego-state therapy have been described by different authors and under different names. It is suggested that core concepts related to ego-state theory and therapy of guided hypnotic dissociation may underlie the core of clinical effectiveness in many contemporary psychotherapeutic methods.