Posttraumatic stress disorder (PTSD) and insomnia are characterized by sleep disturbances and daytime functional impairments. Actigraphy metrics can quantify diurnal rhythms via interdaily stability, intradaily variability, relative amplitude, and sleep regularity. Here, we (a) compared diurnal rhythms in PTSD, insomnia, and healthy control samples using linear mixed modeling; (b) compared inter-individual variability of diurnal rhythms between groups using variance ratio tests; and (c) examined correlations between diurnal rhythms and sleep measures within the clinical samples. Participants (N = 98) wore wrist-activity monitors for one week and completed the Insomnia Severity Index and Pittsburgh Sleep Quality Index. Both clinical samples displayed significantly lower interdaily stability, relative amplitude, and sleep regularity compared with controls. Individuals with PTSD and insomnia did not differ on mean diurnal rhythm metrics. Both clinical samples showed more inter-individual variability in relative amplitude compared with controls, and the individuals with PTSD were distinguished from those with insomnia by greater inter-individual variability in interdaily stability and relative amplitude. Relative amplitude in the clinical samples was positively correlated with objective sleep efficiency and total sleep time. This is the first study to compare individuals with PTSD and insomnia on measures of diurnal rhythms, revealing those with PTSD and insomnia to have less robust and more variable diurnal rhythms compared with controls. Individuals with PTSD differed from those with insomnia in inter-individual variability of diurnal rest-activity stability and amplitude, highlighting this population as particularly heterogenous. Diurnal rhythm robustness might be considered an intervention target in insomnia and PTSD populations.

创伤后应激障碍 (PTSD) 和失眠的特点是睡眠障碍和日间功能障碍。活动记录指标可以通过日间稳定性、日内变异性、相对幅度和睡眠规律来量化昼夜节律。在这里，我们 (a) 使用线性混合模型比较了 PTSD、失眠和健康对照样本的昼夜节律；(b) 使用方差比检验比较组间昼夜节律的个体间变异性；(c) 检查临床样本中昼夜节律和睡眠测量之间的相关性。参与者（N= 98) 佩戴手腕活动监测器一周，完成失眠严重程度指数和匹兹堡睡眠质量指数。与对照组相比，两种临床样本的日间稳定性、相对幅度和睡眠规律性均显着降低。患有 PTSD 和失眠症的个体在平均昼夜节律指标上没有差异。与对照组相比，这两个临床样本在相对振幅方面表现出更大的个体间变异性，而患有 PTSD 的个体与失眠症个体的区别在于日间稳定性和相对振幅的个体间变异性更大。临床样本中的相对幅度与客观睡眠效率和总睡眠时间呈正相关。这是第一项比较患有 PTSD 和失眠症患者的昼夜节律测量的研究，揭示了与对照组相比，患有 PTSD 和失眠症的人的昼夜节律不那么健壮和多变。患有 PTSD 的个体与患有失眠症的个体在昼夜休息活动稳定性和幅度的个体间变异性方面有所不同，这突出了这一群体的异质性。昼夜节律稳健性可能被认为是失眠和 PTSD 人群的干预目标。