BACKGROUND Population-based and family studies showed that impulsive-aggression predicts suicidality; however, the underlying etiological nature of this association is poorly understood. The objective was to determine the contribution of genes and environment to the association between childhood impulsive-aggression and serious suicidal ideation/attempt in young adulthood. METHODS N = 862 twins (435 families) from the Quebec Newborn Twin Study were followed up from birth to 20 years. Repeated measures of teacher-assessed impulsive-aggression were modeled using a genetically informed latent growth model including intercept and slope parameters reflecting individual differences in the baseline level (age 6 years) and in the change (increase/decrease) of impulsive-aggression during childhood (6 to 12 years), respectively. Lifetime suicidality (serious suicidal ideation/attempt) was self-reported at 20 years. Associations of impulsive-aggression intercept and slope with suicidality were decomposed into additive genetic (A) and unique environmental (E) components. RESULTS Additive genetic factors accounted for an important part of individual differences in impulsive-aggression intercept (A = 90%, E = 10%) and slope (A = 65%, E = 35%). Genetic (50%) and unique environmental (50%) factors equally contributed to suicidality. We found that 38% of the genetic factors accounting for suicidality were shared with those underlying impulsive-aggression slope, whereas 40% of the environmental factors accounting for suicidality were shared with those associated with impulsive-aggression intercept. The genetic correlation between impulsive-aggression slope and suicidality was 0.60, p = .027. CONCLUSIONS Genetic and unique environmental factors underlying suicidality significantly overlap with those underlying childhood impulsive-aggression. Future studies should identify putative genetic and environmental factors to inform prevention.

中文翻译：

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基因和环境对儿童冲动攻击和青春期自杀行为之间纵向关联的贡献。

背景 基于人群和家庭的研究表明，冲动攻击预示着自杀；然而，人们对这种关联的潜在病因学性质知之甚少。目的是确定基因和环境对童年冲动攻击和成年青年严重自杀意念/企图之间关联的贡献。方法 N = 862 对来自魁北克新生儿双胞胎研究的双胞胎（435 个家庭）进行了从出生到 20 年的随访。教师评估的冲动攻击的重复测量使用遗传信息的潜在增长模型进行建模，包括截距和斜率参数反映基线水平（6岁）和儿童时期冲动攻击的变化（增加/减少）的个体差异（6 至 12 岁），分别。终生自杀倾向（严重的自杀意念/企图）是在 20 岁时自我报告的。冲动攻击拦截和斜率与自杀的关联被分解为加性遗传 (A) 和独特的环境 (E) 组件。结果 加性遗传因素在冲动攻击截距（A = 90%，E = 10%）和斜率（A = 65%，E = 35%）的个体差异中占重要部分。遗传 (50%) 和独特的环境 (50%) 因素同样导致自杀。我们发现 38% 的导致自杀的遗传因素与那些潜在的冲动攻击斜率共享，而 40% 的导致自杀的环境因素与那些与冲动攻击拦截相关的因素共享。冲动攻击斜率与自杀倾向之间的遗传相关性为0。60，p = .027。结论 导致自杀的遗传和独特的环境因素与那些潜在的儿童冲动攻击显着重叠。未来的研究应确定假定的遗传和环境因素，以提供预防信息。