Towards a nondualistic approach to multisystem illness.

There is an increasing interest in understanding the etiology and treatment of patients who present with multiple chronic symptoms. The thesis of this comment is that the understanding of these problems and progress on effective treatment will be greatly enhanced by emerging new models that go beyond dualistic distinctions like those between organic versus functional disorders and psychological versus physiological causation. The outline of this new model includes a focus on common neurobiological and behavioral mechanisms that operate across disorders including altered pain modulation, affect regulation, and illness coping. Exciting new areas of research include functional and structural brain imaging studies and more recent studies linking imaging with genetic markers, behavior, and autonomic responses. These new studies, carried out across illness populations, hold great promise to tie together the data on psychosocial, genetic, and biological mechanisms of these complicated clinical problems.