Neurological soft signs in adolescents with poor performance on the continuous performance test: markers of liability for schizophrenia spectrum disorders?

There is much evidence that neurological soft signs (NSS) are highly preval ent in both adults and children with schizophrenia. In addition, they have been detected as early precursors of a schizophrenic outcome in at-risk sub jects. Such findings point to the possible value of NSS as neurointegrative markers in schizophrenia which has been hypothesized to be a neurodevelopm ental disease. In our study we used a biobehavioral criterion to select the 'at-risk' group, a sustained attentional deficit as measured by the contin uous performance test (CPT). We compared 140 normal adolescents with 162 'C PT-linked vulnerable' adolescents (index subjects) on a battery for the ass essment of NSS (including laterality), IQ, frontal lobe function and schizo typy. An association was found between NSS and attentional deficit. Further more, index subjects with NSS were characterized by lower IQ scores, poorer performance on frontal lobe tests and greater problems with social interac tion. There was also a trend for an association between male sex and both l eft-handedness and NSS. (C) 1999 Elsevier Science Ireland Ltd. Al rights re served.