Role of Immunity in Pathogenesis of Psychosis

The involvement of immunity in the pathogenesis of schizophrenia and related psychoses was suspected a century ago but was shadowed by the dopaminergic hypothesis after the discovery of antipsychotics. We currently know that this latter theory has many limits and cannot account for the wide variety of psychotic conditions. The immune-inflammatory theory is now one of the most promising axes of research in terms of pathogenesis of several mental health conditions. Immunity and inflammation play a role at least in a subgroup of patients with psychosis. The immune system is complex with a variety of components and mediators that can all have effects on the brain and thus mediate psychiatric symptoms. In this chapter we will explore the scientific evidence of the role of immune system in pathophysiology of psychosis. The sections of this chapter will discuss the role of innate system components (cytokines, microglia, inflammation.), the role of adaptive system (lymphocytes and antibodies) with a section focusing on auto-immunity and particularly antineuronal antibodies. Finally we will discuss how this research can impact patients management and elaborate recommendations for future research