West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China.
Center of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
Elife. 2020 Jul 14;9:e56860. doi: 10.7554/eLife.56860.
Losing a co-twin by death is a severely stressful event yet with unknown impact on the surviving twin's risk of psychiatric disorders. We identified all Swedish-born twins who lost a co-twin by death between 1973 and 2013 (n = 4,528), their 4939 non-twin full siblings, together with 22,640 age- and sex-matched non-bereaved twins. Compared to the non-bereaved twins, exposed twins were at increased risk of receiving a first diagnosis of psychiatric disorders (hazard ratio = 1.65, 95% confidence interval1.48-1.83), particularly during the first month after loss. Similarly, compared to non-twin full siblings, the relative risks were significantly increased after loss of monozygotic co-twin (2.45-fold), and loss of a dizygotic co-twin (1.29-fold), with higher HR observed with greater age gaps between twins and non-twin siblings. As dizygotic twins share equal genetic relatedness to the deceased twin as their full siblings, this pattern suggests that beyond the contribution of genetic factors, shared early life experiences and attachment contribute to the risk of psychiatric disorders among surviving twins after co-twin loss.
失去同胞手足是一件极其有压力的事情，但对幸存同胞手足患精神障碍的风险影响未知。我们确定了所有在 1973 年至 2013 年间失去同胞手足的瑞典出生的双胞胎（n = 4528）及其 4939 名非同胞手足全同胞，以及 22640 名年龄和性别匹配的非丧亲双胞胎。与非丧亲双胞胎相比，暴露于丧亲事件的双胞胎患精神障碍的首次诊断风险更高（危险比=1.65，95%置信区间为 1.48-1.83），尤其是在丧失后的第一个月。同样，与非同胞手足全同胞相比，双胞胎失去同卵双胞胎（风险比为 2.45 倍）和失去异卵双胞胎（风险比为 1.29 倍）后，相对风险显著增加，双胞胎与非同胞手足之间的年龄差距越大，HR 越高。由于异卵双胞胎与已故双胞胎的遗传相关性与同胞手足相同，这种模式表明，除了遗传因素的贡献外，共同的早期生活经历和依恋也会导致同胞手足在失去同胞手足后患上精神障碍的风险增加。
