Psychic distress and the immune response.

This minireview surveys recent progress in the field of immunoregulation by the central nervous system. Representative findings from human and animal studies show evidence for significant immunosuppression in states of psychic distress. Mechanisms of immunomodulation are discussed in light of data implicating neuroendocrine, genetic, neuroanatomical, and learning factors. Evidence for reciprocal modulation of immune and nervous systems is considered. A simple hierarchical model proposes traits that are acted on by environment and experience to produce chronic states of mental health vs. psychic distress; these states determine baseline immunocompetence and response to afferent signals during acute immune challenge. Multidisciplinary interest in psychoneuroimmunology has accelerated the rate of inquiry into the mechanistic details of immunoregulation and has generated new appreciation for the pervasive effects of mental status on physiologic homeostasis.