Dr Ramesh Manocha discusses psychoneuroimmunology in this excerpt from his thesis.
Possibly the most significant psychobehaviuoral factor associated with immunological consequences is negative emotion. Negative affect has frequently been associated with immunological dysregulation in a wide variety of scenarios ranging from stress, depression to laboratory manipulations. In fact negative affect has been proposed as a final common pathway by which these various psychosocial factors, personality traits, coping styles and dispositions impact on the central nervous system and then immunological activity ultimately manifesting as effects on health.