Correlation between electroencephalography and heart rate variability during sleep

It is known that autonomic nervous activities change in correspondence with sleep stages. However, the characteristics of continuous fluctuations in nocturnal autonomic nerve tone have not been clarified in detail. The study aimed to determine the possible correlation between the electroencephalogram (EEG) and autonomic nervous activities, and to clarify in detail the nocturnal fluctuations in autonomic nerve activities. Overnight EEGs and electrocardiograms of seven healthy males were obtained. These EEGs were analyzed by fast Fourier transformation algorithm to extract delta, sigma and beta power. Heart rate and heart rate variability (HRV) were calculated in consecutive 5-min epochs. The HRV indices of low frequency (LF), high frequency (HF) and LF/HF ratio were calculated from the spectral analysis of R-R intervals. The sleep stages were manually scored according to Rechtschaffen and Kales' criteria. Low frequency and LF/HF were significantly lower during non-rapid eye movement (NREM) than REM, and were lower in stages 3 and 4 than in stages 1 and 2. Furthermore, delta EEG showed inverse correlations with LF (r = - 0.44, P < 0.001) and LF/HF (r = - 0.41, P < 0.001). In contrast, HF differed neither between REM and NREM nor among NREM sleep stages. Detailed analysis revealed that correlation was evident from the first to third NREM, but not in the fourth and fifth NREM. Delta EEG power showed negative correlations with LF and LF/HF, suggesting that sympathetic nervous activities continuously fluctuate in accordance with sleep deepening and lightening.     

Social trauma and its association with posttraumatic stress disorder and social anxiety disorder

The key characteristic of a traumatic event as defined by the Diagnostic and Mental Manual of Mental Disorders (DSM) seems to be a threat to life. However, evidence suggests that other types of threats may play a role in the development of PTSD and other disorders such as social anxiety disorder (SAD). One such threat is social trauma, which involves humiliation and rejection in social situations. In this study, we explored whether there were differences in the frequency, type and severity of social trauma endured by individuals with a primary diagnosis of SAD (n = 60) compared to a clinical control group of individuals with a primary diagnosis of obsessive compulsive disorder (OCD, n = 19) and a control group of individuals with no psychiatric disorders (n = 60). The results showed that most participants in this study had experienced social trauma. There were no clear differences in the types of experiences between the groups. However, one third of participants in the SAD group (but none in the other groups) met criteria for PTSD or suffered from clinically significant PTSD symptoms in response to their most significant social trauma. This group of SAD patients described more severe social trauma than other participants. This line of research could have implications for theoretical models of both PTSD and SAD, and for the treatment of individuals with SAD suffering from PTSD after social trauma.     

Effects of caffeine on heart rate and QT variability during sleep

Administration of caffeine in the evening produces poor sleep. Patients with insomnia have characteristic electrocardiogram (ECG) changes, including increased heart rate (HR), increased sympathetic activity, and decreased parasympathetic activity. Fifteen young adult normal subjects slept in the laboratory for several nights prior to randomization into a caffeine protocol where subjects received caffeine 400 mg 30 min prior to one night of sleep and placebo randomly prior to another night. ECG was sampled at a rate of 500 Hz and recorded onto a PC. Data samples of 256-s periods of the ECG trace were taken from wake (before sleep), stage II, and REM for placebo and caffeine conditions. A peak detection algorithm was used to identify the R-R intervals (in milliseconds) from the ECG. A common QT variability algorithm was used to find the QT interval for each beat using the time-stretch model. The powers for HR and QT series were integrated in the bands of LF (low frequency: 0.04-0.15 Hz) and HF (high frequency: 0.15-0.5 Hz) bands. There was a significant caffeine by sleep stage interaction for LF/HF ratios (F = 4.0; df = 2, 18; P = .04). LF/HF ratios were significantly higher during REM following caffeine administration. There was also a significant caffeine by sleep stage interaction for QTvi (QT variability normalized for mean QT interval divided by HR variability normalized for mean HR; F = 5.6; df = 2, 12; P = .02). QTvi was also significantly higher during REM following caffeine administration. The higher LF/HF ratios and QTvi during REM are most likely due to the sympathetic effects of caffeine. These findings suggest that excessive caffeine intake may result in adverse cardiovascular events in vulnerable subjects.     

The PCL as a brief screen for posttraumatic stress disorder within schizophrenia

Objectives: To assess the utility of using the posttraumatic checklist (PCL) as a screening measure for identifying posttraumatic stress disorder (PTSD) in individuals diagnosed with a psychotic disorder.

Methods: The PCL was administered to 165 participants as part of a clinical trial. Those scoring 44 or above on the PCL underwent further assessment using the clinician administered PTSD scale (CAPS).

Results: Overall 18.2% of the sample exhibited a diagnostic level of PTSD symptoms, as indicated by the CAPS assessment. Only 29.7% of those who scored above the PCL threshold were diagnostic of PTSD.

Conclusions: The use of PCL for identifying PTSD within this population is not recommended.     

Early predictors of posttraumatic stress disorder.

The benefits of providing early intervention for people recently exposed to trauma have highlighted the need to develop means to identify people who will develop chronic posttraumatic stress disorder (PTSD). This review provides an overview of prospective studies that have indexed the acute reactions to trauma that are predictive of chronic posttraumatic stress disorder. Ten studies of the predictive power of the acute stress disorder diagnosis indicate that this diagnosis does not have adequate predictive power. There is no convergence across studies on any constellation of acute symptoms that predict posttraumatic stress disorder. A review of biological and cognitive mechanisms occurring in the acute posttraumatic phase suggests that these factors may provide more accurate means of predicting chronic posttraumatic stress disorder. Recommendations for future research to facilitate identification of key markers of acutely traumatized people who will develop posttraumatic stress disorder are discussed.     

Persistence of sleep disturbances following cognitive-behavior therapy for posttraumatic stress disorder

Objectives

The objectives of the present study were (1) to assess the impact of cognitive-behavior therapy (CBT) for posttraumatic stress disorder (PTSD) on associated sleep disturbances and (2) to explore the correlates of persistent sleep difficulties in terms of anxiety and depression symptoms and perceived health.

Method

Fifty-five individuals with PTSD were administered a series of assessments designed to evaluate sleep, PTSD symptoms, symptoms of anxiety and depression, and perceived health before and after individual CBT for PTSD and at 6-month follow-up.

Results

Significant improvements were observed on sleep quality, sleep onset latency, sleep efficiency, and sleep disturbances. These changes were not fully maintained after 6 months, and 70% of people who reported baseline sleep difficulties (Pittsburgh Sleep Quality Index >5) still reported significant problems with sleep after treatment. Persistent sleep difficulties were associated with more severe posttraumatic, anxious, and depressive symptoms as well as poorer health.

Conclusion

Although CBT for PTSD had a favorable impact on sleep, the majority of participants suffered from residual sleep difficulties. Individuals with persistent sleep difficulties posttreatment may experience more residual posttraumatic, depression, and anxiety symptoms and poorer mental and physical health than those who do not report sleep problems posttreatment. Further research in this area will allow clinicians to treat sleep problems in these individuals more effectively.     

Initial symptoms and reactions to trauma-related stimuli and the development of posttraumatic stress disorder

We investigated laboratory and experimental variables as predictors of the development of posttraumatic stress disorder (PTSD). Evoked heart rate response to trauma-related pictures, attentional bias in the dot-probe task, and viewing time were assessed in 35 victims of a traumatic event and again after 3 months. Data was compared to 26 control participants. At first assessment trauma victims showed heart rate (HR) acceleration and controls showed HR deceleration to trauma-related material. The group of trauma victims improved clinically over time. Predictors of the number of PTSD symptoms after 3 months were re-experiencing (33% of the variance) and amplitude of the evoked HR reaction to trauma-related pictures (15%). The two variables were highly correlated. Trauma victims were also more anxious, viewed trauma-related pictures for a longer time, and had a longer reaction time in the dot-probe task (but no distinct attentional bias) than control participants. Results indicate that specific fear responses and re-experiencing contribute to the development of posttraumatic stress disorder.     

心率变异指标在焦虑症评估中的应用

目的 探讨心率变异指标在焦虑症评估中的作用.方法 对33例焦虑症患者及28例正常对照者进行心率变异检测,结束后进行焦虑自评量表及匹兹堡睡眠质量指数评定.结果 焦虑症患者的窦性RR间期的标准差、极低频带低于正常对照者,差异非常显著,总频谱、高频带低于正常组,差异显著,睡眠质量指数得分明显低于对照组;时域指标窦性RR间期的标准差与频域各指标存在明显相关.结论 焦虑症患者心率变异性降低.     

Altered cortisol awakening response in posttraumatic stress disorder

An altered function of the hypothalamic-pituitary-adrenal axis is assumed to be characteristic for Posttraumatic Stress Disorder (PTSD), although there is inconsistent empirical evidence. Only few studies examined the awakening cortisol response and a daytime profile in PTSD. Salivary cortisol levels were measured at seven intervals from awakening until 8 PM in trauma-exposed subjects with (N=29) and without PTSD (N=19) and in 15 non-exposed controls. While the three groups did not differ with respect to their first cortisol level immediately after awakening, the expected cortisol increase to awakening 15-60 min later was significantly lower in PTSD patients compared to non-PTSD subjects and healthy controls. This effect remained stable when trauma-exposed subjects with comorbid major depression were excluded from the analysis. A significant negative correlation between the overall cortisol secretion (AUC(G)) and overall PTSD symptomatology and hyper-arousal symptoms was found. The findings are discussed in light of the hypothesis of a counterregulation of hyper-arousal symptoms and chronic stress in PTSD.     

Women's posttraumatic stress symptoms and autism spectrum disorder in their children

Maternal posttraumatic stress disorder (PTSD) may be associated with autism spectrum disorder (ASD) in offspring through multiple pathways: maternal stress may affect the fetus; ASD in children may increase risk of PTSD in mothers; and the two disorders may share genetic risk. Understanding whether maternal PTSD is associated with child's ASD is important for clinicians treating children with ASD, as PTSD in parents is associated with poorer family functioning. We examined the association of maternal PTSD with offspring ASD in a large US cohort (N ASD cases = 413, N controls = 42,868). Mother's PTSD symptoms were strongly associated with child's ASD (RR 4–5 PTSD symptoms = 1.98, 95% CI = 1.39, 2.81; RR 6–7 symptoms = 2.89, 95% CI = 2.00, 4.18). Clinicians treating persons with ASD should be aware of elevated risk of PTSD in the mother. Genetic studies should investigate PTSD risk alleles in relation to ASD.     

Comorbid posttraumatic stress disorder and major depressive disorder: The usefulness of a sequential treatment approach within a randomised design

Cognitive Processing Therapy (CPT) and Behavioural Activation Therapy (BA) were used to treat individuals with comorbid posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). Fifty-two individuals (48 women, 4 men) were randomized to CPT alone (n = 18), CPT then BA for MDD (n = 17), or BA then CPT (n = 17). Presenting trauma was primarily interpersonal (87 %). Participants were assessed at pre-, posttreatment, and 6-month follow-up. PTSD and MDD symptoms were the main outcome of interest; trauma cognitions, rumination, and emotional numbing were secondary outcomes. All groups showed sizeable reductions in PTSD and depression (effect sizes at follow-up ranging between 1.02–2.54). A pattern of findings indicated CPT/BA showed better outcomes in terms of larger effect sizes and loss of diagnoses relative to CPT alone and BA/CPT. At follow-up greater numbers of the CPT/BA group were estimated to have achieved good end-state for remission of both PTSD and depression (49 %, CI₉₅ [.26, .73]) relative to CPT alone (18 %, CI₉₅ [.03, .38]) and BA/CPT (11 %, CI₉₅ [.01, .29]). Although tempered by the modest sample size, the findings suggest that individuals with comorbid PTSD and MDD may benefit from having PTSD targeted first before remaining MDD symptoms are addressed.     

Psychological trauma,posttraumatic stress disorder and trauma-related depression: A mini-review

There are various types of traumatic stimuli, such as catastrophic events like wars, natural calamities like earthquakes, and personal trauma from physical and psychological neglect or abuse and sexual abuse. Traumatic events can be divided into type I and type II trauma, and their impacts on individuals depend not only on the severity and duration of the traumas but also on individuals’ self-evaluation of the traumatic events. Individual stress reactions to trauma include posttraumatic stress disorder (PTSD), complex PTSD and trauma-related depression. Trauma-related depression is a reactive depression with unclear pathology, and depression occurring due to trauma in the childhood has gained increasing attention, because it has persisted for a long time and does not respond to conventional antidepressants but shows good or partial response to psychotherapy, which is similar to the pattern observed for PTSD. Because trauma-related depression is associated with high risk of suicide and is chronic with a propensity to relapse, it is necessary to explore its pathogenesis and therapeutic strategy.     

癌症相关创伤后应激障碍患者心率变异性研究

目的:探讨癌症相关创伤后应激障碍(PTSD)患者的心率变异性(HRV). 方法:采用临床用创伤后应激功能障碍诊断量表(CAPS)对150例癌症患者进行诊断性访谈,并分为PTSD组(37例)和非PTSD组(nPTSD组,30例);应用PTSD自评量表(PCL-C)对两组患者进行评估;采用生理相干与自主神经平衡系统对PTSD组、nPTSD组、健康对照(NC)组(30名)进行短时HRV检测,分析HRV指标与PTSD核心症状的相关性. 结果:与nPTSD组和NC组比较,PTSD组平静状态下R-R间期标准差(SDNN)和高频功率(HF)较显著下降,低频功率(LF)/HF显著升高(P均＜0.001);应激状态下PTSD组SDNN应激差值明显降低,HF和LF/HF应激差值显著增高(P均＜0.001);HRV指标与PTSD核心症状的严重程度显著相关(P均＜0.05). 结论:癌症相关PTSD患者自主神经功能紊乱,其核心症状的严重程度与自主神经功能紊乱显著相关.     

Testing whether posttraumatic stress disorder and major depressive disorder are similar or unique constructs

Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) co-occur frequently, are highly correlated, and share three symptoms in common. In the present paper, the authors tested whether PTSD and MDD are similar or unique constructs by examining their symptoms using Rasch modeling. Data were used from the 766 trauma-exposed subjects in the National Comorbidity Survey-Replication (conducted in the early 2000s) with PTSD and MDD symptom ratings. Results demonstrate that MDD symptoms were less frequently endorsed than PTSD symptoms—even for the three symptoms shared between the disorders. PTSD and MDD items represented a single, underlying dimension, although modest support was found for a secondary sub-factor. Removing their shared symptoms, and additional depression-related dysphoria symptoms, continued to result in a single underlying PTSD-MDD symptom dimension. Results raise further questions about PTSD's distinctiveness from MDD, and the causes of their comorbidity.     

焦虑症的特质焦虑水平与心率变异性相关研究

目的：了解焦虑症患者的特质焦虑水平与心率变异性（HRV）这一指标相关性。方法：选取焦虑症患者50例,对其进行汉密尔顿焦虑量表（HAMA）、特质焦虑问卷（T-AI）心理评定,同时用24h动态心电图记录器,对患者进行HRV指标的测定,对其测定24h全部正常心动周期的标准差（SDNN）、正常相邻心动周期差值的均方的平方根（rMSSD）、每5min正常心动周期的标准差（SDANN）、相邻R-R间期差值超过50ins的心搏数占总心搏数的百分比（PNN50）、5min低频功率（LF）、5min高频功率（HF）、5min极低频功率（VLF）、低频和高频比值（LF／HF）8项指标分别与T-AI、HAMA分值进行分析。结果：焦虑症患者的特质焦虑分值与LF／HF具有显著相关性,但并未发现随着特质焦虑分值的增加,HRV频谱指标有差异性改变。结论：焦虑症患者的特质焦虑水平与自主神经功能不平衡性有关。     

Hippocampal function during associative learning in patients with posttraumatic stress disorder

In the last decade several studies have shown memory deficits in patients with posttraumatic stress disorder (PTSD) which have been associated with a reduced hippocampus volume. However, until now we do not know how or whether these structural abnormalities turn into functional abnormalities. Thus, the primary purpose of the present study was the investigation of the hippocampal function using functional magnet resonance imaging (fMRI).We compared PTSD patients and healthy control participants using an associative learning paradigm consisting of two encoding and one retrieval condition. During fMRI scanning participants had to learn face-profession pairs. Afterwards only faces were presented as cue stimuli for associating the category of the prior learned target profession and the participants had to decide whether this face belonged to a scientific or an artistic profession. Additionally, cognitive functioning, i.e. memory and attention, was examined using neuropsychological standard tests.During encoding PTSD patients showed stronger hippocampal and weaker prefrontal activation compared to healthy control participants. During retrieval the two groups did not differ neither in hippocampus activation nor in accuracy of retrieval. PTSD patients however showed a reduced activation in the left parahippocampal gyrus and other memory-related brain regions. We did not find any significant memory differences between PTSD patients and healthy control participants.The results suggest that PTSD has an effect on memory-related brain function despite intact memory functioning. In particular the hippocampal/parahippocampal regions and the prefrontal cortex show functional alterations during associative learning and memory.     

Self-mutilative behaviors in male veterans with posttraumatic stress disorder

Self-mutilative behaviors (SMB) were examined in a sample of male veterans with posttraumatic stress disorder (PTSD). The primary objective was to determine the prevalence of SMB and any physical, cognitive, or affective antecedents and correlates for these behaviors. Participants included 509 male veterans with PTSD and levels of PTSD, depression, alcohol use, hostility, and impulsivity were evaluated to determine if these variables were related to SMB. Antecedents and sequelae of SMB were also examined to generate hypotheses regarding the functions of these behaviors. A second type of habit behavior, body-focused repetitive behaviors (BFRB), was also examined as part of the study. Findings indicated that veterans who engaged in either type of habit behavior were younger than those who did not engage in SMB or BFRB. Veterans reporting SMB also reported higher levels of PTSD, depression, hostility, and impulsivity compared to the BFRB and no-habit groups. Examination of habit antecedents and sequelae showed support for the automatic-positive reinforcement function of SMB. These findings are discussed in the context of research and treatment involving male veterans with PTSD who engage in SMB.     

Gene-environment interaction in posttraumatic stress disorder

The purpose of this article is to encourage research investigating the role of measured gene-environment interaction (G × E) in the etiology of posttraumatic stress disorder (PTSD). PTSD is uniquely suited to the study of G × E as the diagnosis requires exposure to a potentially-traumatic life event. PTSD is also moderately heritable; however, the role of genetic factors in PTSD etiology has been largely neglected both by trauma researchers and psychiatric geneticists. First, we summarize evidence for genetic influences on PTSD from family, twin, and molecular genetic studies. Second, we discuss the key challenges in G × E studies of PTSD and offer practical strategies for addressing these challenges and for discovering replicable G × E for PTSD. Finally, we propose some promising new directions for PTSD G × E research. We suggest that G × E research in PTSD is essential to understanding vulnerability and resilience following exposure to a traumatic event. Dr. Koenen is supported in part by US-NIMH K08 MH070627. Ananda Amstadter is supported by US-NIAAA T32 AA007474. Nicole Nugent is supported by US-NIMH T32 MH18869.