Exposure therapy is an effective treatment for posttraumatic stress disorder (PTSD), but a comprehensive, emotion-focused perspective on how psychotherapy affects brain function is lacking. The authors assessed changes in brain function after prolonged exposure therapy across three emotional reactivity and regulation paradigms.

Individuals with PTSD underwent functional MRI (fMRI) at rest and while completing three tasks assessing emotional reactivity and regulation. Individuals were then randomly assigned to immediate prolonged exposure treatment (N=36) or a waiting list condition (N=30) and underwent a second scan approximately 4 weeks after the last treatment session or a comparable waiting period, respectively.

Treatment-specific changes were observed only during cognitive reappraisal of negative images. Psychotherapy increased lateral frontopolar cortex activity and connectivity with the ventromedial prefrontal cortex/ventral striatum. Greater increases in frontopolar activation were associated with improvement in hyperarousal symptoms and psychological well-being. The frontopolar cortex also displayed a greater variety of temporal resting-state signal pattern changes after treatment. Concurrent transcranial magnetic stimulation and fMRI in healthy participants demonstrated that the lateral frontopolar cortex exerts downstream influence on the ventromedial prefrontal cortex/ventral striatum.

Changes in frontopolar function during deliberate regulation of negative affect is one key mechanism of adaptive psychotherapeutic change in PTSD. Given that frontopolar connectivity with ventromedial regions during emotion regulation is enhanced by psychotherapy and that the frontopolar cortex exerts downstream influence on ventromedial regions in healthy individuals, these findings inform a novel conceptualization of how psychotherapy works, and they identify a promising target for stimulation-based therapeutics.

暴露疗法是一种治疗创伤后应激障碍（PTSD）的有效方法，但缺乏关于心理疗法如何影响脑功能的全面，以情感为中心的观点。作者评估了在三种情绪反应和调节模式下长期暴露治疗后脑功能的变化。

PTSD患者在休息时完成功能性MRI（fMRI），同时完成三项评估情绪反应和调节的任务。然后将个体随机分配到立即延长暴露治疗（N = 36）或等待名单条件（N = 30），并分别在上次治疗后约4周或相当的等待时间进行第二次扫描。

仅在阴性图像的认知重新评估过程中观察到治疗特定的变化。心理治疗增加了外侧额极皮层的活动以及与腹侧前额叶皮层/腹侧纹状体的连通性。前极激活的更大增加与过度兴奋症状和心理健康的改善有关。在治疗后，额极皮层还显示出更多的时间静止状态信号模式变化。健康参与者同时经颅磁刺激和功能磁共振成像显示，外侧额极皮层对腹侧前额叶皮层/腹侧纹状体施加下游影响。

故意调节负面情绪的过程中前极功能的变化是PTSD适应性心理治疗变化的关键机制之一。鉴于通过心理疗法可以增强情绪调节过程中与前腹区的前极连接性，并且前额皮质对健康个体的前腹区产生下游影响，这些发现为心理疗法的工作原理提供了新颖的概念，并确定了基于刺激的有前途的目标疗法。