title: Reaction time of the Continuous Performance Test is an endophenotypic marker for schizophrenia: a study of first-episode neuroleptic-naive schizophrenia, their non-psychotic first-degree relatives and healthy population controls.
abstract: Sustained attention has been proposed as an endophenotype of schizophrenia, and consequently may be useful as a quantitative trait in genetic studies. In the present study, we used the continuous performance test (CPT) to measure sustained attention in 112 first-episode and neuroleptic-naive schizophrenic patients, 296 of their non-psychotic first-degree relatives, and 452 normal controls. Compared with controls, probands with schizophrenia showed worse performance on all measures of CPT. Parents, siblings and offspring of probands were also impaired on 'hit reaction time', an index of psychomotor processing speed of the correct response. Hit reaction time was also independent of the acute clinical features of the disease, indicating it is a trait rather than a state marker. Our findings supported the use of the hit reaction time measure of the CPT as an endophenotype marker for schizophrenia.
authors.affiliation: Psychiatric laboratory and Department of Psychiatry, West China Hospital, Sichuan University, Sichuan Chengdu, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Raymond
authors.initials: R
authors.lastname: Chan
authors.forename: Jinhua
authors.initials: J
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Yao
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
authors.forename: Xueli
authors.initials: X
authors.lastname: Sun
authors.forename: Xiehe
authors.initials: X
authors.lastname: Liu
authors.forename: Pak C
authors.initials: PC
authors.lastname: Sham
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Ma
authors.forename: Huaqing
authors.initials: H
authors.lastname: Meng
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
authors.forename: David A
authors.initials: DA
authors.lastname: Collier
authors.forename: Tao
authors.initials: T
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D005260:Female; D005819:Genetic Markers / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010641:Phenotype; D011594:Psychometrics; D011597:Psychomotor Performance; D011930:Reaction Time / Q000235:genetics*; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics*
chemical_list: D005819:Genetic Markers