Stress, affective disorders, and immune function.

Increasing scientific evidence supports age-old observations that psychosocial factors are closely associated with the pathogenesis of certain physical and mental illnesses. The immune system appears to play a primary mediating role. Whereas acute stress may initiate a transient immunologically protective response, prolonged or poorly controlled psychosocial stressors may result in depression of different components of the immune system. These responses may be related to, or independent of, changes in the neuroendocrine system. As the rather prolific literature in this infant area of psychoneuroimmunology reveals, there are many complex levels of interaction that require further investigation. There is clearly a need for long-term prospective studies that will identify individuals at risk for those numerous diseases in which psychosocial factors and impaired immune function play a pathogenic role. In addition to correlating altered immune function over time with changes in the physical environment, these studies should include psychologic profiles, life-event inventories, and psychiatric interviews in an effort to delineate the role of psychosocial factors as the stimulus for and as the response to the disease process. One of the many positive outcomes of this multifactorial approach to illness is that it will alter the physician's approach to disease and thus to patients as they are evaluated and treated in the psychosocial context in which they live. As Hippocrates said, "It is more important to know what sort of a person has a disease than to know what sort of disease a person has."