Jardine R, Martin N G, Henderson A S
Genet Epidemiol. 1984;1(2):89-107. doi: 10.1002/gepi.1370010202.
A genetic analysis of the trait of neuroticism and symptoms of anxiety and depression in 3,810 pairs of adult MZ and DZ twins is reported. Differences between people in these measures can be explained simply by differences in their genes and in their individual environmental experiences. There is no evidence that environmental experiences that are shared by cotwins, such as common family environment or social influences, are important. There are differences between the sexes in gene action affecting neuroticism, and genetic effects become more pronounced with age in females. The lack of evidence for dominance variance affecting neuroticism contrasts well with the detection of considerable genetical nonadditivity for extraversion in the same sample and reinforces the view that these two traits are not only statistically, but also genetically, quite independent. An analysis of the causes of covariation between anxiety, depression, and neuroticism shows that additive gene effects are more important causes of covariation than environmental factors. Genetic variation in symptoms of anxiety and depression is largely dependent on the same factors as effect the neuroticism trait. However, there is also evidence for genetic variation specific to depression.
本文报告了对3810对成年同卵双胞胎和异卵双胞胎的神经质特质以及焦虑和抑郁症状的基因分析。这些测量指标在个体间的差异可以简单地由基因差异和个体环境经历差异来解释。没有证据表明双胞胎共同经历的环境因素，如共同的家庭环境或社会影响，是重要的。影响神经质的基因作用存在性别差异，且在女性中基因效应随年龄增长而更加显著。缺乏影响神经质的显性方差证据，这与在同一样本中检测到的外向性的显著遗传非加性形成鲜明对比，强化了这两个特质不仅在统计学上，而且在遗传学上都相当独立的观点。对焦虑、抑郁和神经质之间协变原因的分析表明，加性基因效应是协变的更重要原因，而非环境因素。焦虑和抑郁症状的基因变异在很大程度上取决于影响神经质特质的相同因素。然而，也有证据表明存在特定于抑郁的基因变异。
