Some mental health problems such as depression and anxiety are more common in females, while others such as autism and attention deficit/hyperactivity (AD/H) are more common in males. However, the neurobiological origins of these sex differences are poorly understood. Animal studies have shown substantial sex differences in neuronal and glial cell structure, while human brain imaging studies have shown only small differences, which largely reflect overall body and brain size. Advanced diffusion MRI techniques can be used to examine intracellular, extracellular, and free water signal contributions and provide unique insights into microscopic cellular structure. However, the extent to which sex differences exist in these metrics of subcortical gray matter structures implicated in psychiatric disorders is not known. Here, we show large sex-related differences in microstructure in subcortical regions, including the hippocampus, thalamus, and nucleus accumbens in a large sample of young adults. Unlike conventional T1-weighted structural imaging, large sex differences remained after adjustment for age and brain volume. Further, diffusion metrics in the thalamus and amygdala were associated with depression, anxiety, AD/H, and antisocial personality problems. Diffusion MRI may provide mechanistic insights into the origin of sex differences in behavior and mental health over the life course and help to bridge the gap between findings from experimental, epidemiological, and clinical mental health research.

中文翻译：

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性和心理健康与皮层下大脑微观结构有关


抑郁和焦虑等一些心理健康问题在女性中更为常见，而自闭症和注意力缺陷/多动 (AD/H) 等其他心理健康问题在男性中更为常见。然而，人们对这些性别差异的神经生物学起源知之甚少。动物研究显示神经元和神经胶质细胞结构存在显着的性别差异，而人类大脑成像研究显示只有很小的差异，这在很大程度上反映了整体身体和大脑的大小。先进的扩散 MRI 技术可用于检查细胞内、细胞外和自由水信号的贡献，并提供对微观细胞结构的独特见解。然而，与精神疾病有关的皮层下灰质结构的这些指标中存在性别差异的程度尚不清楚。在这里，我们在大量年轻人样本中显示了皮层下区域微观结构与性别相关的巨大差异，包括海马体、丘脑和伏核。与传统的 T1 加权结构成像不同，在调整年龄和脑容量后，仍然存在较大的性别差异。此外，丘脑和杏仁核的扩散指标与抑郁、焦虑、AD/H 和反社会人格问题相关。扩散 MRI 可以为生命过程中行为和心理健康性别差异的起源提供机制见解，并有助于弥合实验、流行病学和临床心理健康研究结果之间的差距。