Season of birth and electrodermal unresponsiveness in male schizophrenics

The present study was designed to examine differences in the electrodermal activity of schizophrenics born in the season of excessive risk (January-April), and those born in the season of nonexcessive risk (May-December). Thirty-two male schizophrenics were presented with a series of orienting tones (1000 Hz, 80dB, 2 sec duration) while electrodermal activity was monitored. They were subdivided according to season of birth and compared in three electrodermal variables, and also in some background and clinical parameters. We found that schizophrenics born in the season of excessive risk were characterized by significantly lower electrodermal activity and more negative symptoms than those born in the season of nonexcessive risk.