Amygdala function is implicated in the pathogenesis of autism spectrum disorder (ASD) and anxiety. We investigated associations between early trajectories of amygdala growth and anxiety and ASD outcomes at school age in two longitudinal studies: high- and low-familial likelihood for ASD, Infant Brain Imaging Study (IBIS, n = 257) and typically developing (TD) community sample, Early Brain Development Study (EBDS, n = 158). Infants underwent MRI scanning at up to 3 timepoints from neonate to 24 months. Anxiety was assessed at 6–12 years. Linear multilevel modeling tested whether amygdala volume growth was associated with anxiety symptoms at school age. In the IBIS sample, children with higher anxiety showed accelerated amygdala growth from 6 to 24 months. ASD diagnosis and ASD familial likelihood were not significant predictors. In the EBDS sample, amygdala growth from birth to 24 months was associated with anxiety. More anxious children had smaller amygdala volume and slower rates of amygdala growth. We explore reasons for the contrasting results between high-familial likelihood for ASD and TD samples, grounding results in the broader literature of variable associations between early amygdala volume and later anxiety. Results have the potential to identify mechanisms linking early amygdala growth to later anxiety in certain groups.

杏仁核功能与自闭症谱系障碍（ASD）和焦虑的发病机制有关。我们在两项纵向研究中调查了杏仁核生长和焦虑的早期轨迹与学龄 ASD 结局之间的关联：ASD 的高和低家族可能性、婴儿脑成像研究 (IBIS，n = 257) 和典型发育 (TD) 社区样本，早期大脑发育研究（EBDS，n = 158）。从新生儿到 24 个月，婴儿在最多 3 个时间点接受了 MRI 扫描。焦虑症在 6-12 岁时进行评估。线性多级模型测试了杏仁核体积增长是否与学龄期焦虑症状相关。在 IBIS 样本中，焦虑程度较高的儿童在 6 至 24 个月期间杏仁核生长加速。ASD 诊断和 ASD 家族可能性并不是显着的预测因素。在 EBDS 样本中，杏仁核从出生到 24 个月的生长与焦虑有关。焦虑程度较高的儿童杏仁核体积较小，杏仁核生长速度较慢。我们探讨了 ASD 和 TD 样本的高家族可能性之间出现对比结果的原因，并将结果建立在早期杏仁核体积与后期焦虑之间可变关联的更广泛文献中。结果有可能确定某些群体中早期杏仁核生长与后期焦虑之间的联系机制。