Reinier van Arkel groep, 's-Hertogenbosch, The Netherlands.
J Affect Disord. 2012 Feb;136(3):294-303. doi: 10.1016/j.jad.2011.11.034. Epub 2011 Dec 12.
Although the genetic risk to develop bipolar disorder is present from conception, the first frank symptoms of the illness generally become evident in late adolescence or early adulthood. However, except for pediatric bipolar disorder (PBD), it is still unclear when the first signs of the illness in adults become apparent and whether these are related to the genetic risk to develop bipolar disorder. This study examined whether underperformance at school precedes the onset of the illness and is a genetically related risk marker for developing bipolar disorder.
Information on school performance was obtained using objective archival data from 53 bipolar twin pairs (24 monozygotic (MZ), 29 dizygotic (DZ)) and 42 healthy matched control twin pairs (23 MZ, 19 DZ).
Affected twin pairs completed significantly fewer years of education than did control twin pairs with no difference between bipolar patients and their non-bipolar cotwins. The underperformance at school in the affected twin pairs occurred in early adolescence at a significantly younger age than the control twin pairs and preceded the onset of the first frank episode of bipolar disorder by thirteen years. Median age at onset of underperformance was not different in the patients and their non-bipolar cotwins. The association between liability of bipolar disease and age of first underperformance was significant and could be explained by genetic factors.
The sample is not a population based twin sample.
Underperformance at school during early adolescence may be a genetic marker for the vulnerability to develop bipolar disorder.
尽管从受孕时起就存在患上双相情感障碍的遗传风险，但该病的首次明显症状通常出现在青春期后期或成年早期。然而，除了儿童双相情感障碍（PBD）之外，目前尚不清楚成年人首次出现该病症状的确切时间，以及这些症状是否与患上双相情感障碍的遗传风险有关。本研究旨在探讨在校表现不佳是否先于疾病发作出现，以及是否是患上双相情感障碍的一种与遗传相关的风险标志物。
通过 53 对双相情感障碍双胞胎（24 对同卵双生子（MZ），29 对异卵双生子（DZ））和 42 对健康匹配的对照双胞胎（23 对 MZ，19 对 DZ）的客观档案数据，获取了有关在校表现的信息。
与对照组相比，受影响的双胞胎完成的受教育年限明显较少，而双相情感障碍患者与其非双相情感障碍同卵双胞胎之间没有差异。受影响的双胞胎在校表现不佳发生在青春期早期，比对照组早了整整 13 年，而且先于首次出现明显的双相情感障碍发作。在患者及其非双相情感障碍同卵双胞胎中，出现表现不佳的年龄中位数没有差异。双相情感障碍疾病易感性与首次表现不佳年龄之间的关联具有统计学意义，且可以用遗传因素来解释。
该样本不是基于人群的双胞胎样本。
青春期早期在校表现不佳可能是患上双相情感障碍的遗传标志物。
