Cognitive functioning of first-episode schizophrenia patients and their healthy siblings

Abstract

Objective To explore difference of neuropsychological tests among first-episode schizophrenia patients,their healthy siblings and healthy controls,and to explore the possible endophenotype of schizophrenia in cognitive function.Methods In all,92 first-episode schizophrenia patients,56 their healthy siblings and 62 healthy controls were assessed with the Category Fluency Test ( CFT),Digit Symbol Coding Test ( DSCT),Trail Making Test (TMT),Wechsler Memory Scale-Ⅲ Spatial Span Test ( WMS-ⅢSST ),Hopkins Verbal Learning Test-Revised (HVLT-R),Brief Visuospatial Memory Test-Revised (BVMT-R),Paced Auditory Seria Addition Test (PASAT),Wisconsin Card Sorting Test-64 (WCST-64).Results The patients showed poorer performance on all measures of neuropsychological tests than healthy controls (P ＜0.01 ).There were significantly lower performances in siblings than controls in CFT,DSCT,TMT,HVLT-R trials 1-3,HVLT-R delay,BVMT-R trials 1-3,PASAT,and perseverative errors,perseverative responses and categories completed of WCST-64 ( P ＜ 0.05 ). There were no significance between patients and siblings in CFT and perseverative errors,perseverative responses and categories completed of WSCT-64 [ ( 18.40 ± 12.12 ) vs.( 18.86 ± 5.19 ),( 16.48 ± 8.19 ) vs.( 14.80 ± 5.86 ),( 18.76 ± 10.91 ) vs.( 16.86 ± 7.73 ),( 1.33 ± 2.81 ) vs.( 1.63 ± 1.36 ) respectively ] ( P ＞ 0.05 ),but patients performed worse than siblings in other any measures ( P ＜ 0.05 ).Conclusions It indicates that the first-episode schizophrenia patients have multiple cognitive deficits in speed of processing,working memory,verbal learning and memory,visual learning and memory,attention/vigilance,and executive function,and their healthy siblings show cognitive function deficits in speed of processing,attention/vigilance,verbal learning and memory,visual learning and memory and executive function.Semantic fluency function and executive function may be the potential endophenotype of schizophrenia. Key words: Schizophrenia; Siblings; Cognition; Endophenotype