孕期人际心理治疗与婴儿右侧海马体积差异相关

这项研究做了什么

这项研究关注的是一条此前证据薄弱的链条：孕期抑郁如何影响胎儿大脑，以及治疗能否改变这一过程。文章介绍，过去关于孕期抑郁与儿童心理健康的行为学发现大多是相关性的，神经生物学证据不多。为此，Care Project 的研究者对孕期抑郁者及其婴儿开展了一项随机试验，婴儿在6周时接受脑部扫描，6个月时接受情绪评估。

参与者共109名孕妇，其中50%为白人，51%使用 Medicaid。她们被随机分配到两组：一组接受8周人际心理治疗，另一组接受“增强常规照护”，包括抑郁教育和附近心理健康资源信息。这种设计让研究者可以比较“接受专门心理治疗”与“获得一般信息支持”两种情况的差异，而不只是观察抑郁母亲与不抑郁母亲之间的差别。

关键发现：右侧海马小了约5%

结果显示，在婴儿6周时，母亲接受心理治疗的一组，婴儿右侧海马体积平均比对照组小约5%。海马是大脑内部与学习和记忆有关的区域。左侧海马没有出现组间差异，邻近的杏仁核——同样参与学习和恐惧反应——也没有差异。也就是说，变化是局部的、单侧的，并非整个内侧颞叶系统的普遍改变。

更值得注意的是后续关联：6周时海马较小的婴儿，在6个月时倾向于表现出更好的情绪调节。这一方向与“海马越大越好”的直觉相反，但文章只把它作为观察到的关联呈现，并未给出因果解释。

另一个反直觉的结果是，婴儿海马体积与母亲抑郁症状改善的程度并不相关。研究者据此提出一种解释：人际心理治疗除了改善情绪，可能还改变了母亲的应激水平、激素生物学或饮食等健康行为，进而影响胎儿发育。这属于研究者的推测，文章没有提供验证这些通路的直接数据。

如何理解“更小”与“更好”

把“右侧海马体积小5%”直接读成损害或优势都不合适。在成人研究中，海马体积常与记忆、应激相关，但婴儿期大脑正处于快速发育中，体积差异的意义不能照搬成人结论。这项研究本身也没有报告6个月时情绪调节差异的效应量，读者无法判断这一关联的强度。

文章给出的是一条谨慎的表述链：治疗可能影响婴儿大脑发育，后者又可能影响早期情绪发展。两个“可能”都保留着，因为脑影像和行为评估虽然按顺序进行，但各自只在一个时间点测量，无法追踪同一批婴儿大脑与行为的共同变化轨迹。

研究边界与作者表态

文章明确列出两点局限：尽管队列在种族和社会经济背景上有一定多样性，但母亲全部从丹佛一个都市区招募；脑影像和情绪行为测试虽然先后进行，但每项都只做了一次。这意味着结果能否推广到其他地区人群、以及6周的海马差异是否持续，都还没有答案。

共同作者、丹佛大学的 Elysia Davis 在新闻稿中表示，研究结果提示治疗孕期母亲的抑郁可能有助于塑造更健康的婴儿大脑发育轨迹，并称孕期是干预的关键窗口。这是作者对研究意义的解读，属于观点性表述，而非试验直接证明的结论。对读者而言，这项研究提供的核心信息是：孕期抑郁治疗与婴儿大脑发育之间存在可测量的关联，但关联的方向、机制和长期意义仍待更多研究。

Receiving psychotherapy for depression while pregnant can influence how your baby’s brain develops—which in turn may influence early emotional development, according to research findings published in Nature Communications.

Why It Matters

Many research studies have shown that untreated depression during pregnancy adversely impacts the mental health of the child as well as the mother. The behavioral findings to date are largely correlational, however, and have little supporting neurobiological evidence.

As part of the Care Project, researchers conducted a randomized trial of pregnant individuals with depression and their babies, including brain scans at six weeks and emotional assessments at six months for the babies.

By the Numbers

• A total of 109 pregnant individuals (50% White, 51% on Medicaid) were randomized to eight weeks of interpersonal psychotherapy or enhanced usual care that included depression education and information on nearby mental health resources.
• At six weeks of age, the babies whose mothers received psychotherapy had on average 5% less volume in the right hippocampus, an inner brain region involved in learning and memory). There was no difference in the left hippocampus between groups, nor in the neighboring amygdala, which is also involved in learning and fear.
• The babies with smaller hippocampi at six weeks tended to demonstrate better emotional regulation at six months.

What’s More

Interestingly, the size of an infant’s hippocampus did not correlate with the degree of depression improvement in the mother. The researchers suggested that in addition to its effects on mood, interpersonal psychotherapy might have altered mothers’ stress, hormonal biology, and/or health behaviors like diet, which then impacted fetal development.

The Other Side

Though the study cohort was racially and socioeconomically diverse, the mothers were recruited from just one metropolitan area (Denver). And while the brain imaging and behavioral tests happened sequentially, each was done at just one point in time.

Takeaway Message

“Our findings suggest that treating mother’s depression during pregnancy may help shape a healthier developmental trajectory for the infant brain,” said co-author Elysia Davis, Ph.D., of the University of Denver in a news release. “This study highlights pregnancy as a critical window for intervention and reinforces that supporting maternal mental health is also an investment in child health.”

Related Information

Source

Catherine H. Demers, et al. Impact of prenatal maternal depression intervention on infant hippocampal and amygdala development: a randomized clinical trial. Nature Communications. Published October 16, 2026. 10.1038/s41467-026-78276-4

(Image: Getty Images/iStock/pixologicstudio)