Anxiety disorders are the most prevalent mental health conditions worldwide. Unfortunately, the understanding of the precise neurobiological mechanisms that underlie these disorders remains limited. Current diagnostic classifications, based on observable symptoms rather than underlying pathophysiology, do not capture the heterogeneity within and across anxiety disorders. Recent advances in functional neuroimaging have provided new insights into the neural circuits implicated in pathological anxiety, revealing dysfunctions that cut across traditional diagnostic boundaries. In this Review, we synthesize evidence that highlights abnormalities in neurobehavioural systems related to negative valence, positive valence, cognitive systems and social processes. We emphasize that pathological anxiety arises not only from heightened reactivity in acute threat (‘fear’) circuits but also from alterations in circuits that mediate distant (potential) and sustained threat, reward processing, cognitive control and social processing. We discuss how circuit vulnerabilities can lead to the emergence and maintenance of pathological anxiety. Once established, these neural abnormalities can be exacerbated by maladaptive behaviours that prevent extinction learning and perpetuate anxiety disorders. By delineating the specific neural mechanisms in each neurobiological system, we aim to contribute to a more comprehensive understanding of the neurobiology of anxiety disorders, potentially informing future research directions in this field.

焦虑症是全球最普遍的心理健康状况。不幸的是，对这些疾病背后的确切神经生物学机制的理解仍然有限。目前的诊断分类基于可观察到的症状而不是潜在的病理生理学，并未捕捉焦虑障碍内部和之间的异质性。功能神经影像学的最新进展为与病理性焦虑有关的神经回路提供了新的见解，揭示了跨越传统诊断界限的功能障碍。在本综述中，我们综合了证据，突出了与负效价、正效价、认知系统和社会过程相关的神经行为系统异常。我们强调，病态焦虑不仅源于急性威胁（“恐惧”）回路的高度反应性，还源于介导远期（潜在）和持续威胁、奖励加工、认知控制和社会加工的回路的改变。我们讨论了回路脆弱性如何导致病理性焦虑的出现和维持。一旦确定，这些神经异常可能会因适应不良行为而加剧，这些行为会阻止灭绝学习并使焦虑症长期存在。通过描述每个神经生物学系统中的特定神经机制，我们的目标是为更全面地理解焦虑症的神经生物学做出贡献，从而可能为该领域的未来研究方向提供信息。