Chapter 10 - Immune Activity and Psychopathology

Abstract

This chapter examines how infection and immune activity are linked to changes in cognitive and emotional function. When pathology does not occur within the central nervous system (CNS), the processes by which it alters behavior are thought to involve mediators such as cytokines or antibodies. There are many brain disorders in which immune activity has been implicated. Most disorders of this type are regarded as neurological. Pathogens must enter the body, and this occurs across surfaces such as the skin and the mucosal linings of the respiratory, gastrointestinal, and genitourinary tracts. Given that pathogens penetrate into the CNS, immune responses within the CNS must occur. However, the CNS has long been regarded as a privileged site, where immune responses do not occur easily. Cell-mediated responses must be highly regulated within the CNS because of the potential for destruction of cells that may be virally infected but that will not regenerate. Psychosocial events alter brain activity, which then affects immune activity and thereby modifies control over microbial growth. In turn, microbial penetration leads to immune activation, which alters brain activity and modifies psychosocial experience.