Neuropsychological functioning among non-psychotic siblings and parents ofschizophrenic patients

Several studies have shown subtle neuropsychological deficits in healthy re latives of schizophrenic patients. However, older relatives and parents hav e been less frequently assessed than younger adult relatives and siblings. Furthermore, some areas of neuropsychological functioning such as memory an d learning have been little studied. Thirty-seven 22-70-year-old non-psycho tic parents and siblings of schizophrenic patients were compared to 37 heal thy control subjects on a battery of neuropsychological tests (Trail Making , parts A and B, verbal fluency, Wisconsin Card Sorting Test, and four subt ests of the Wechsler Memory Scale-Revised: logical memory, design reproduct ion, verbal paired associates and digit span). Relatives did not differ fro m control subjects on Wisconsin Card Sorting Test performance and on visual memory, but were significantly impaired on verbal fluency; more subtle def icits were found on Trail Making, part B, digit span and paired associates. A higher proportion of relatives than control subjects showed impairment o n verbal fluency and verbal memory. These neuropsychological weaknesses wer e present as much in siblings as in parents of schizophrenic patients, and age did not cancel differences between relatives and control subjects. Thus , these subtle deficits seem to be potential phenotypic markers of schizoph renia. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.