Psychosocial criteria for patient selection: review of studies and concepts for understanding chronic back pain.

Eighteen studies on psychosocial aspects of back pain are reviewed. Among six studies trying to differentiate pain of organic and functional origin, only two studies claim to be able to make such a distinction. Psychological disturbance--studied with a variety of instruments--proved to be an important factor affecting the reporting and measurement of pain (eight studies). Low disturbance can predict good outcome in both organic and functional pain (six studies). Psychological disturbance, however, seems to be equally the consequence and the cause of pain, and pain relief reduces psychological disturbance. Thus, the dichotomy of organic vs. psychogenic pain must be dismissed, and a holistic, interactive systems model must be advocated. Factors causing acute back pain should be differentiated from those leading to chronicity. A model for understanding the evolution of chronicity and a checklist for possible factors promoting chronicity are presented.