Psychoneuroimmunology, Stress and Infection
Psychoneuroimmunology is concerned with the effects of the mind on the immune system. Stress has been a focal point in psychoneuroimmunology largely because of its demonstrated effects on immune function. It becomes even more intimately involved in nervous system-immune system interactions, because infections and certain other immune challenges can be regarded as stressful. A common human experience is that under acute stress conditions, an impending infection, such as a cold, can be held at bay, but when the pressure is relaxed, one succumbs to the cold. Extensive experimental data from animal and human studies indicate that adrenally compromised individuals are more susceptible to infections, and that this property involves the adrenal cortex rather than the medulla. Infections which activate the immune system appear to act as stressors, probably via the production of cytokines. Thus stress, infection and immune system function are intimately involved in complex relationships critical for the survival of the organism.