[Psychotherapy and its efficacy in chronic pain-a critical review.].

The gate control theory resulted in intensified consideration and investigation of psychological factors in the pathogenesis and continuation of chronic pain. This had led to an increasing interest in the efficacy of psychotherapy for such patients. The different forms of psychotherapy (hypnosis, relaxation, behavior therapy, psychodynamically oriented therapy) currently most often applied are reviewed with notes on the methods and the efficacy recorded for each. The psychodynamically oriented approach has most often been omitted from previous reviews but is integrated in this paper. Four psychodynamic mechanisms are differentiated: the narcissistic mechanism ("psychoprothetic function" of pain), the conversion mechanism ("symbolic function" of pain), the psychovegetative tension mechanism (pain as equivalent of emotion) and the learning mechanism (secondary gain from pain). Generally speaking, a good level of efficacy was ascertained for each form of psychotherapy considered. Hypnosis and relaxation can reduce depression and the perception of pain. Operant programs reduce medication intake and increase the level of activity. Cognitive behavioral strategies are aimed at changing the pain patient's fixation on the body. Psychodynamic approaches concentrate on biographical factors and communication with significant others before the onset of pain reflected in the therapist-patient relationship. However, the value of the results is restricted by the lack of information on patient selection in nearly all the studies considered. The small numbers of patients evaluated in most of the studies suggest that the population investigated may well not be representative, especially if the difficulty of motivating chronic pain patients to present for psychotherapy is taken into account. In addition, a diagnostic classification of the population investigated is lacking. Conclusions are drawn for the planning of future therapy studies.