Donders Institute for Brain Cognition and Behaviour: Centre for Cognitive Neuroimaging (DCCN). Kapitelweg 29, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands; Behavioural Science Institute, Radboud University, Thomas van Aquinostraat 4, 6525 GD Nijmegen, Netherlands.
Behavioural Science Institute, Radboud University, Thomas van Aquinostraat 4, 6525 GD Nijmegen, Netherlands.
EBioMedicine. 2022 Jul;81:104094. doi: 10.1016/j.ebiom.2022.104094. Epub 2022 Jun 10.
The freezing response is a universal response to threat, linked to attentive immobility and action preparation. It is relevant for acute stress coping in animals and humans, and subtle deviations in toddler freezing duration (absence of, or excessively long reactions) have been linked to higher risk for internalizing symptoms in adolescence. Yet, while individual freezing tendencies are relatively stable throughout life, little is known about their gene-environment aetiology.
We investigated the heritability of toddler freezing in the Quebec Newborn Twin Study (QNTS; n=508 twins) by fitting behavioural genetic models to video-coded freezing responses during a robot confrontation. Furthermore, we examined the predictive associations between toddler freezing and internalizing symptoms (anxiety and depressive symptoms), as they unfold during adolescence (ages 12-19 years) using linear mixed-effects models.
Freezing was found to be moderately heritable (45% of the variance accounted for by genetic factors). The remaining variance was explained by unique environmental factors, including measurement error. No significant contribution of shared environmental factors was noted. Additionally, shorter freezing was associated with more internalizing symptoms in adolescence at trend level, a pattern that was significant for depressive but not anxiety symptoms.
Freezing is an adaptive coping mechanism in early childhood, which is partly driven by genetic factors. Crucially, the absence or shorter duration of these behaviours may signal vulnerability to depressive problems later in life.
Canadian Institutes of Health Research and Research Fund of Quebec-Health and Society and Culture. Consolidator grant from the European Research Council (ERC_CoG-2017_772337).
冻结反应是一种普遍的威胁反应，与注意力不集中和行动准备有关。它与动物和人类的急性应激应对有关，幼儿冻结持续时间（无反应或反应时间过长）的细微偏差与青春期内化症状的风险增加有关。然而，尽管个体的冻结倾向在整个生命中相对稳定，但人们对其基因-环境病因知之甚少。
我们通过对机器人对抗过程中视频编码的冻结反应进行行为遗传模型拟合，调查了魁北克新生儿双胞胎研究（QNTS；n=508 对双胞胎）中幼儿冻结的遗传性。此外，我们使用线性混合效应模型，检查了幼儿冻结与内化症状（焦虑和抑郁症状）之间的预测关联，这些症状在青春期（12-19 岁）期间逐渐显现。
发现冻结具有中度遗传性（45%的方差由遗传因素决定）。其余方差由独特的环境因素解释，包括测量误差。未注意到共享环境因素有显著贡献。此外，在青春期，冻结时间越短，内化症状越多，这种模式在抑郁症状上有显著意义，但在焦虑症状上没有显著意义。
冻结是幼儿期的一种适应性应对机制，部分受遗传因素驱动。至关重要的是，这些行为的缺失或持续时间较短可能预示着以后生活中出现抑郁问题的脆弱性。
加拿大卫生研究院和魁北克卫生与社会及文化研究基金会。欧洲研究理事会（ERC_CoG-2017_772337）巩固资助。
