What does electrodermal activity tell us about prognosis in the schizophrenia spectrum?

Various dysfunctions in electrodermal activity (EDA) have been found in schizophrenic patients. The present paper reviews evidence that the electrodermal dysfunctions may carry prognostic information regarding subsequent symptoms, as well as social and occupational outcome. Although the findings are not entirely consistent, heightened electrodermal activity as indicated by frequent orienting responses to innocuous stimuli, elevated skin conductance level (SCL), and frequent non-specific skin conductance responses (NS-SCR) is most often associated with poor symptomatic, social, and occupational outcome in schizophrenic patients. There have been no studies that have directly examined electrodermal prognostic indicators in schizotypal individuals. However, high-risk studies suggest that heightened electrodermal activity may be prognostic of poor outcome in schizotypals as well. Thus, abnormally high electrodermal arousal and reactivity is predictive of poor outcome in at least some patients. The theoretical implications of these findings and directions for further research are briefly discussed.