Cognitive functions in schizotypal personality disorder

Objective: Schizophrenia spectrum subjects have cognitive deficits in a var iety of domains. Schizotypal personality disordered (SPD) subjects do not h ave many of the confounds seen in schizophrenic patients, but may have the same pattern of cognitive deficits in attention and executive functioning. Hypotheses: We hypothesized that SPD subjects would have impairments on mea sures of attention, abstract reasoning, cognitive inhibition, working memor y and verbal recognition memory when compared to normal subjects, and that these deficits would be intermediate to those observed in schizophrenic pat ients. Method: SPD subjects (N = 20) were compared to age-, gender- and edu cation-matched schizophrenic patients (N = 20) and normal comparison subjec ts (N = 20) on a battery of cognitive measures. Results: The data were anal yzed using standard statistical methods, including effect sizes. Using a co nservative alpha level of 0.01, schizophrenic patients had deficits on many of these measures compared to normal subjects. Although the SPD subjects d id not significantly differ from normal comparison subjects at the p < 0.01 level, there were trends (p < 0.019-0.028) toward impairment on measures o f working memory and general intellectual functioning. On further effect si ze analyses, SPD subjects performed intermediate to normals and schizophren ic patients on measures of attention, abstract reasoning, cognitive inhibit ion, verbal working memory, recognition memory, and general intellectual fu nctioning, with moderate to large effect sizes separating groups. Conclusio ns: These results suggest that SPD subjects have possible widespread cognit ive deficits that are of lesser magnitude than those observed in schizophre nic patients. (C) 1999 Elsevier Science B.V. All rights reserved.