Linking Stress and Schizophrenia: A Focus on Prepulse Inhibition

Schizophrenia affects about 0.5-1.0% of people worldwide, occurring roughly equally in both men and women. The exact causes of schizophrenia are not fully understood, although the consensus of current research is that schizophrenia is a developmental disorder, caused by a genetic liability interacting with environmental and psychosocial stress. However, the possible neurobiological mechanisms underlying this gene-stress interaction are largely unknown. To study the role of stress in the development of schizophrenia, it is useful to dissect this complex disease into specific symptoms. In this respect, a well-accepted model for psychotic-like behavior is prepulse inhibition (PPI) of the startle response. In an attempt to clarify the link between stress and schizophrenia, this chapter reviews experimental studies that determined the effect of acute and chronic stressors on PPI in humans and rodents. In section 2, studies that have focused on stress in adulthood will be discussed, and in section 3, studies that have addressed effects of early-life stress on PPI will be outlined. Together, the findings of these PPI studies support the neurodevelopmental theories of schizophrenia, which state that insults, including stress, experienced during early brain development could particularly increase the risk of developing schizophrenia.