Chen W J, Liu S K, Chang C J, Lien Y J, Chang Y H, Hwu H G
Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei.
Am J Psychiatry. 1998 Sep;155(9):1214-20. doi: 10.1176/ajp.155.9.1214.
The authors investigated whether nonpsychotic relatives of schizophrenic probands have an elevated risk of deficits in sustained attention as measured by the Continuous Performance Test (CPT), whether such deficits are associated with specific factors of schizotypy, and whether poor CPT performance by probands predicts poor performance by their relatives. In addition, the heritability of CPT performance in the families of schizophrenic probands was estimated.
The study subjects were 60 schizophrenic probands, 148 of their first-degree relatives, 20 normal comparison probands, and 42 of the comparison probands' first-degree relatives. Subjects completed undegraded and 25% degraded sessions of the CPT and were interviewed with use of the Chinese version of the Diagnostic Interview for Genetic Studies. Subjects' CPT sensitivity indexes, d', were standardized against those of a community sample of 345 subjects, with adjustment for age, sex, and level of education.
On average, the d' values of the relatives of schizophrenic probands were lower than those of the relatives of comparison probands but higher than those of schizophrenic probands. Lower sensitivity indexes among the relatives of schizophrenic patients were associated with the interpersonal dysfunction and disorganization factors of schizotypy but not the cognitive/perceptual factor. When schizophrenic probands were divided into two subgroups by a cutoff of -3.0 for adjusted z score on the CPT, the d' values of relatives of probands with CPT deficits were lower than those of relatives of probands without deficits. The estimated heritability of performance on the CPT ranged from 0.48 to 0.62.
Sustained attention deficit may be a genetic vulnerability marker for schizophrenia, and it may be more useful in linkage analysis than traditional phenotype definitions of schizophrenia.
作者研究了精神分裂症先证者的非精神病性亲属通过连续作业测试（CPT）测量的持续注意力缺陷风险是否升高，此类缺陷是否与分裂型人格的特定因素相关，以及先证者的CPT表现不佳是否预示其亲属表现不佳。此外，还估计了精神分裂症先证者家庭中CPT表现的遗传度。
研究对象为60名精神分裂症先证者、其148名一级亲属、20名正常对照先证者以及42名对照先证者的一级亲属。研究对象完成了CPT的未降级和25%降级测试，并接受了中文版的遗传研究诊断访谈。研究对象的CPT敏感性指数d'根据345名社区样本对象进行标准化，并对年龄、性别和教育水平进行了调整。
平均而言，精神分裂症先证者亲属的d'值低于对照先证者亲属，但高于精神分裂症先证者。精神分裂症患者亲属中较低的敏感性指数与分裂型人格的人际功能障碍和紊乱因素相关，但与认知/感知因素无关。当根据CPT调整后的z分数-3.0的临界值将精神分裂症先证者分为两个亚组时，CPT有缺陷的先证者亲属的d'值低于无缺陷先证者亲属的d'值。CPT表现的估计遗传度范围为0.48至0.62。
持续注意力缺陷可能是精神分裂症的一种遗传易感性标志物，并且在连锁分析中可能比传统的精神分裂症表型定义更有用。
