Nightmares are a hallmark symptom of posttraumatic stress disorder (PTSD). This strong association may reflect a shared pathophysiology in the form of altered autonomic activity and increased reactivity. Using an acoustic startle paradigm, we investigated the interrelationships of psychophysiological measures during wakefulness and PTSD diagnosis, posttraumatic nightmares, and nontraumatic nightmares.

A community sample of 122 trauma survivors were presented with a series of brief loud tones, while heart rate (HRR), skin conductance (SCR), and orbicularis oculi electromyogram (EMGR) responses were measured. Prior to the tone presentations, resting heart rate variability (HRV) was assessed. Nightmares were measured using nightmare logs. Three dichotomous groupings of participants were compared: (1) current PTSD diagnosis (n = 59), no PTSD diagnosis (n = 63), (2) those with (n = 26) or without (n = 96) frequent posttraumatic nightmares, and (3) those with (n = 22) or without (n = 100) frequent nontraumatic nightmares.

PTSD diagnosis was associated with posttraumatic but not with nontraumatic nightmares. Both PTSD and posttraumatic nightmares were associated with a larger mean HRR to loud tones, whereas nontraumatic nightmare frequency was associated with a larger SCR. EMGR and resting HRV were not associated with PTSD diagnosis or nightmares.

Our findings suggest a shared pathophysiology between PTSD and posttraumatic nightmares in the form of increased HR reactivity to startling tones, which might reflect reduced parasympathetic tone. This shared pathophysiology could explain why PTSD is more strongly related to posttraumatic than nontraumatic nightmares, which could have important clinical implications.

噩梦是创伤后应激障碍 (PTSD) 的标志性症状。这种强烈的关联可能以改变的自主神经活动和增加的反应性的形式反映了共同的病理生理学。使用声学惊吓范式，我们调查了觉醒和 PTSD 诊断、创伤后噩梦和非创伤性噩梦期间心理生理学措施的相互关系。

向 122 名创伤幸存者的社区样本提供一系列简短的响亮音调，同时测量心率 (HRR)、皮肤电导 (SCR) 和眼轮匝肌肌电图 (EMGR) 反应。在音调呈现之前，评估了静息心率变异性 (HRV)。噩梦是使用噩梦日志来衡量的。比较了三组参与者：(1) 目前有 PTSD 诊断（n = 59），无 PTSD 诊断（n = 63），(2) 有（n = 26）或没有（n = 96）频繁的创伤后噩梦， (3) 那些有（n = 22）或没有（n = 100）频繁的非创伤性噩梦。

PTSD 诊断与创伤后噩梦有关，但与非创伤性噩梦无关。创伤后应激障碍和创伤后噩梦都与较大的响亮音调平均 HRR 相关，而非创伤性噩梦频率与较大的 SCR 相关。EMGR 和静息 HRV 与 PTSD 诊断或噩梦无关。

我们的研究结果表明 PTSD 和创伤后噩梦之间存在共同的病理生理学，表现为 HR 对惊吓音调的反应性增加，这可能反映了副交感神经张力的降低。这种共同的病理生理学可以解释为什么 PTSD 与创伤后噩梦的关系比非创伤性噩梦更强烈，这可能具有重要的临床意义。