IMPAIRED AUTONOMIC NERVOUS-SYSTEM HABITUATION IN THOSE AT GENETIC RISK FOR SCHIZOPHRENIA

Background: Schizophrenia has been associated with habituation of skin conductance activity. Skin conductance data from the Copenhagen High Risk Project were analyzed. We hypothesized that genetic risk for schi zophrenia and development of schizophrenia later in life are related t o impaired habituation of autonomic nervous system activity. Methods: Data were collected in 1962, when subjects averaged 15 years of age an d had not yet qualified for a psychiatric diagnosis. Nonspecific fluct uations in electrodermal activity were monitored during a rest period free of sensory stimulation. Results: We found that an increasing leve l of genetic risk for schizophrenia was related to impaired habituatio n of autonomic nervous system activity over time. Individuals with two schizophrenia-spectrum parents evidenced no habituation, those with o ne spectrum parent evidenced some habituation, and those with normal p arents evidenced rapid habituation. Subjects who developed schizophren ia in adulthood evidenced significant deficits in habituation in adole scence.Conclusions: These results suggest that impaired habituation of spontaneous autonomic nervous system activity may represent a behavio ral marker of the genetic predisposition to schizophrenia.