Laboratory stress tasks induce strong changes in linear and non-linear indices of heart rate variability (HRV) among healthy adults, due to a task-induced parasympathetic withdrawal. Previous findings suggested that negative affectivity and its correlates (i.e., depressive symptoms, anxiety, hostility, type D personality, and situational stress) could profoundly affect autonomic activity. However, to date no studies considered these psychological dimensions simultaneously while trying to disentangle their acute effects on HRV during a laboratory stress task. A total of 65 healthy participants completed a battery of questionnaires and later underwent a psychosocial stress protocol, which involves a stressful and a non-stressful mental arithmetic task, with the latter serving as a control condition for the former. During the entire procedure, autonomic activity was recorded through a portable ECG device. We analysed longitudinal changes in HRV indices using Mixed Models, taking into account respiration rates and the associations between psychophysiological variables through bivariate Pearson’s r (partial) correlation indices. We found significant changes in linear (e.g., HF power, RMSSD) and non-linear (e.g., Poincaré Plot and Correlation Dimension D2) HRV indices during the procedure, with the lowest point reached during the stressful mental arithmetic task. Interestingly, only depressive symptomatology was significantly and positively related to a higher resting-state HRV and to a blunted reactivity to the stress task, even after controlling for baseline values. Results suggest that healthy individuals with higher levels of depressive symptoms could experience atypical cardiovascular responses to stressful events: several speculative interpretations, considering autonomic, behavioral, and motivational dysregulations, are discussed.

中文翻译：

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抑郁症状的较高水平与健康成年人的静息状态心率变异性增加和对实验室压力任务反应迟钝的反应有关。

由于任务引起的副交感神经退缩，实验室压力任务在健康成年人中引起心率变异性（HRV）的线性和非线性指数强烈变化。先前的发现表明，负性情感及其相关性（即抑郁症状，焦虑，敌意，D型人格和处境压力）可能会严重影响自主神经活动。然而，迄今为止，尚无研究在试图消除实验室压力任务期间对HRV的急性影响时同时考虑这些心理因素。共有65名健康参与者完成了一系列问卷调查，随后接受了心理社会压力规程，其中涉及压力性和非压力性心理算术任务，后者是前者的控制条件。在整个过程中 通过便携式ECG设备记录自主活动。我们使用混合模型分析了HRV指标的纵向变化，并考虑了呼吸速率和通过双变量Pearson's得出的心理生理变量之间的关联r（部分）相关指数。我们发现在手术过程中线性（例如，HF功率，RMSSD）和非线性（例如，庞加莱图和相关维数D2）HRV指数发生了显着变化，在紧张的心理算术任务中达到了最低点。有趣的是，即使在控制基线值之后，只有抑郁症状与较高的静息状态HRV和对压力任务的钝化反应显着正相关。结果表明，具有较高抑郁症状水平的健康个体可能会经历针对压力事件的非典型心血管反应：考虑到自主神经，行为和动机失调，讨论了几种推测性解释。