Psychological Factors Affecting Infectious Diseases
HIV infection is the most destructive example of unsafe sexual practices, as a maladaptive health behavior, contributing to development and transmission of an infectious medical condition. Once contracted, HIV infection appeared to be a likely candi-date for important effects of psychological factors, because of the work demonstrating changes in normal immune function after stress, bereavement and depression. The effects of stress and depression on disease progression, immune function and mortality in HIV infection have been an active field of investiga-tion, with varying conclusions. There is less doubt that anxiety worsens symptoms and functioning in HIV patients. No research has demonstrated that depression predicts the onset of somatic symptoms in HIV infection, acquired immunodeficiency syn-drome, or death.
Psychological factors influence other infectious diseases as well, including the common cold, pneumonia, genital her-pes and recurrent urinary tract infections. A number of stud-ies have convincingly shown that psychological stress sup-presses the secondary (but not primary) antibody response to immunization.