Department of Psychology, University of Otago, Dunedin, New Zealand.
Department of Psychiatry and Psychology, Maastricht University, Maastricht, the Netherlands.
Schizophr Bull. 2018 Jun 6;44(4):922-932. doi: 10.1093/schbul/sbx143.
If schizotypy is a taxonic liability for schizophrenia with a general population prevalence of ~10%, it should also be taxonic among biological siblings of probands with schizophrenia. Moreover, assuming this is so, siblings' schizotypy class membership should be predicted by probands' familial load for psychotic disorder and clinical severity, consistent with a multifactorial polygenic threshold model of schizophrenia. We tested these hypotheses in the Genetic Risk and Outcome of Psychosis (GROUP) Study where siblings of probands (n = 792) and unaffected controls (n = 559) provided self-report ratings on the Community Assessment of Psychic Experiences (CAPE). Maximum covariance analyses of control group ratings led to the identification of CAPE items sensitive to nonredundant positive and negative schizotypy classes in the control group (prevalence = 7.9% and 11.1%, respectively). When the same taxonic solution was applied to siblings' CAPE rating, taxometric analyses yielded evidence for larger positive and negative schizotypy classes among siblings (prevalence = 14.1% and 21.8%, respectively). Whereas probands' familial loads for bipolar disorder or drug use disorders did not predict siblings' membership in the schizotypy classes, probands' familial load for psychotic disorder did. Siblings were more likely to be members of the positive schizotypy class where their probands were more severely affected. The pattern of findings is consistent with Meehl's argument that schizotypy reflects liability for schizophrenia.
如果精神分裂症特质是一种具有约 10%一般人群患病率的精神分裂症分类责任因素，那么它也应该在精神分裂症患者的生物学兄弟姐妹中具有分类责任因素。此外，假设情况确实如此，那么兄弟姐妹的精神分裂症特质类别成员身份应该可以由患者的精神病家族负担和临床严重程度来预测，这与精神分裂症的多因素多基因阈值模型一致。我们在遗传风险和精神障碍预后（GROUP）研究中检验了这些假设，该研究中患者（n = 792）和未受影响的对照组（n = 559）的兄弟姐妹提供了社区心理体验评估量表（CAPE）的自我报告评分。对对照组评分进行最大协方差分析导致确定了 CAPE 项目，这些项目可敏感地识别对照组中不冗余的阳性和阴性精神分裂症特质类别（患病率分别为 7.9%和 11.1%）。当将相同的分类解决方案应用于兄弟姐妹的 CAPE 评分时，分类分析结果表明，兄弟姐妹中的阳性和阴性精神分裂症特质类别更大（患病率分别为 14.1%和 21.8%）。尽管患者的双相情感障碍或药物使用障碍家族负担不能预测兄弟姐妹是否属于精神分裂症特质类别，但患者的精神病家族负担可以。在其患者受影响更严重的情况下，兄弟姐妹更有可能成为阳性精神分裂症特质类别的成员。研究结果的模式与 Meehl 的论点一致，即精神分裂症特质反映了对精神分裂症的易感性。
