Measuring liability for schizophrenia using optimized antisaccade stimulusparameters

The ability to identify unaffected gene carriers within families may be cru cial to the success of schizophrenia genetics studies. Data collected from three family samples (N = 365) demonstrated that poor antisaccade performan ce is an exceptionally promising indicator of liability for schizophrenia. A particular antisaccade task version provides large separations (5-6 sigma ) between proband and normal groups. Poor antisaccade performance alone cor rectly identified 70% of patients in California, Utah, and Micronesia schiz ophrenia samples. Twenty-five to 50% of these patients' nonpsychotic first- degree relatives also had poor antisaccade performance, yielding risk ratio s around 20:1 for simplex and 50:1 for multiplex schizophrenia families. Po or antisaccade performance is associated with dorsolateral prefrontal corte x pathology, suggesting that dysfunction of this circuitry also may predisp ose individuals to developing this disease.