Psychoneuroimmunology update.

Psychoneuroimmunology is the scientific field that investigates linkages between the brain, behavior, and the immune system and the implications of these linkages for physical health and disease. Recent evidence suggests that both naturalistic and laboratory stressors can alter enumerative and functional aspects of the human immune system. Chronic stress may increase vulnerability to infectious disease; however, the role of stress in the course of inflammatory bowel disease remains unclear. Because there are large individual differences in psychological response to stress, it is important to consider the role of cognitive and affective responses to stress. Depression has been associated with functional immune decrements and immune overactivation. Cognitive states such as perceived control, views of the self, and views of the future have been associated with immune parameters and health in some studies. Very few controlled clinical trials have been conducted to determine if psychosocial interventions can impact the immune system and the progression of medical conditions. There is suggestive evidence for the health benefits of relaxation training, cognitive-behavioral stress management, and support groups; but, there is little research on many other psychosocial interventions in widespread use for medical conditions. An evidence-based discussion of this research literature with interested patients may help them make informed decisions regarding adjunctive treatments.