Depression is more frequent among individuals exposed to traumatic events. Both trauma exposure and depression are heritable. However, the relationship between these traits, including the role of genetic risk factors, is complex and poorly understood. When modelling trauma exposure as an environmental influence on depression, both gene-environment correlations and gene-environment interactions have been observed. The UK Biobank concurrently assessed Major Depressive Disorder (MDD) and self-reported lifetime exposure to traumatic events in 126,522 genotyped individuals of European ancestry. We contrasted genetic influences on MDD stratified by reported trauma exposure (final sample size range: 24,094-92,957). The SNP-based heritability of MDD with reported trauma exposure (24%) was greater than MDD without reported trauma exposure (12%). Simulations showed that this is not confounded by the strong, positive genetic correlation observed between MDD and reported trauma exposure. We also observed that the genetic correlation between MDD and waist circumference was only significant in individuals reporting trauma exposure (rg = 0.24, p = 1.8 × 10-7 versus rg = -0.05, p = 0.39 in individuals not reporting trauma exposure, difference p = 2.3 × 10-4). Our results suggest that the genetic contribution to MDD is greater when reported trauma is present, and that a complex relationship exists between reported trauma exposure, body composition, and MDD.

中文翻译：

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英国生物银行对重度抑郁症进行全基因组基因环境分析并报告了一生的创伤经历。

在遭受创伤事件的个体中，抑郁症更为常见。创伤经历和抑郁症都是可遗传的。然而，这些特征之间的关系，包括遗传风险因素的作用，是复杂的且知之甚少。当将创伤暴露建模为环境对抑郁症的影响时，基因-环境相关性和基因-环境相互作用都被观察到。英国生物银行同时评估了 126,522 名欧洲血统基因型个体的重度抑郁症 (MDD) 和自我报告的终生创伤事件暴露情况。我们根据报告的创伤暴露情况分层比较了遗传对 MDD 的影响（最终样本量范围：24,094-92,957）。报告有创伤暴露的 MDD 的基于 SNP 的遗传力 (24%) 高于没有报告创伤暴露的 MDD (12%)。模拟表明，MDD 与报道的创伤暴露之间存在强烈的正向遗传相关性，这并不会混淆这一点。我们还观察到，MDD 和腰围之间的遗传相关性仅在报告创伤暴露的个体中显着（rg = 0.24，p = 1.8 × 10-7 对比 rg = -0.05，p = 0.39 在未报告创伤暴露的个体中，差异 p = 2.3 × 10-4)。我们的研究结果表明，当存在报告的创伤时，遗传对重度抑郁症的影响更大，并且报告的创伤暴露、身体成分和重度抑郁症之间存在复杂的关系。