Academic Centre for the Study of Behavioural Plasticity, Vita-Salute San Raffaele University, Milan, Italy.
Depress Anxiety. 2012 Sep;29(9):754-61. doi: 10.1002/da.21941. Epub 2012 Apr 11.
Separation anxiety disorder (SAD) and separation anxiety symptoms (SA) have been studied both epidemiologically and genetically; however, large between-studies discrepancies emerge relative to the role of genetic, shared-, and nonshared environmental influences on these conditions.
Based upon available literature, 18 cohorts and 31,859 subjects belonging to twin samples in Europe, the United States, and Australia were included in three meta-analytic estimations of: the standardized variance components of etiological influences on SAD/SA, and on the effect of sex and rater.
Meta-analytic estimations carried out on all cohorts showed that within-family (genetic 43% and shared environmental 17%) factors explain most of individual differences for SAD/SA. Meta-heritability estimates were higher among females (.52) than males (.26), whereas nonshared environmental effects were stronger for the latter (.74) than for the former (.41). When SAD/SA was rated by parents, the shared environmental influences were higher than those obtained with self-assessment instruments (.23 versus .05), but this may reflect an age difference between subsamples.
A shared environmental effect is present and important in SAD/SA. Our results support at an etiological level the involvement of parents in treating SAD/SA in children, and the provision of specific strategies to parents to manage their own anxiety.
分离焦虑障碍（SAD）和分离焦虑症状（SA）在流行病学和遗传学方面都有研究；然而，相对于遗传、共同和非共同环境对这些疾病的影响，不同研究之间存在很大的差异。
基于现有文献，我们对来自欧洲、美国和澳大利亚的 18 个队列和 31859 名双胞胎样本中的个体进行了三项荟萃分析，以评估：SAD/SA 的病因影响以及性别和评估者的影响的标准化方差分量。
对所有队列进行的荟萃分析表明，家庭内因素（遗传 43%和共同环境 17%）解释了 SAD/SA 个体差异的大部分。女性（.52）的遗传可归因度估计值高于男性（.26），而后者（.74）的非共享环境效应强于前者（.41）。当 SAD/SA 由父母评定时，共同环境的影响高于自我评估工具（.23 比.05），但这可能反映了亚组之间的年龄差异。
在 SAD/SA 中存在且重要的是共同环境效应。我们的结果在病因学水平上支持父母在治疗儿童 SAD/SA 中发挥作用，并为父母提供特定的策略来管理自己的焦虑。
