Sex differences in heart rate responses to script-driven imagery soon after trauma and risk of posttraumatic stress disorder

A laboratory-based examination of a standardized sexual assault script

BACKGROUND AND OBJECTIVE

Idiographic script-driven imagery is core to both research and treatment related to posttraumatic stress disorder (PTSD), including among individuals with a history of sexual assault. However, there may be benefit in having alternatives to such idiographic techniques. The current study therefore examined multimodal responding to a standardized audio-recorded narrative of a sexual assault.

DESIGN AND METHOD

In this experiment, 105 women (Mage = 19.09, SD = 2.24) were recruited from the community and randomly assigned to listen to a depiction of sexual assault (trauma condition) or a similar experience without sexual assault (control condition).

RESULTS

As hypothesized, relative to the control group, participants in the trauma condition reported greater (a) increases in anxiety, anger, and disgust from pre- to post- manipulation, and (b) distress across the duration of the recording. In contrast to hypotheses, heart-rate did not differ across groups.

CONCLUSIONS

Results suggest listening to a standardized sexual assault narrative, compared to a non-traumatic narrative, effectively increases negative affect. This indicates standardized sexual assault narratives have potential as a traumatic event cue presentation method both for trauma-focused treatment and studying reactions to sexual assault cues.

A prospective examination of sex differences in posttraumatic autonomic functioning

BACKGROUND

Cross-sectional studies have found that individuals with posttraumatic stress disorder (PTSD) exhibit deficits in autonomic functioning. While PTSD rates are twice as high in women compared to men, sex differences in autonomic functioning are relatively unknown among trauma-exposed populations. The current study used a prospective design to examine sex differences in posttraumatic autonomic functioning.

METHODS

192 participants were recruited from emergency departments following trauma exposure (Mean age = 35.88, 68.2% female). Skin conductance was measured in the emergency department; fear conditioning was completed two weeks later and included measures of blood pressure (BP), heart rate (HR), and high frequency heart rate variability (HF-HRV). PTSD symptoms were assessed 8 weeks after trauma.

RESULTS

2-week systolic BP was significantly higher in men, while 2-week HR was significantly higher in women, and a sex by PTSD interaction suggested that women who developed PTSD demonstrated the highest HR levels. Two-week HF-HRV was significantly lower in women, and a sex by PTSD interaction suggested that women with PTSD demonstrated the lowest HF-HRV levels. Skin conductance response in the emergency department was associated with 2-week HR and HF-HRV only among women who developed PTSD.

CONCLUSIONS

Our results indicate that there are notable sex differences in autonomic functioning among trauma-exposed individuals. Differences in sympathetic biomarkers (BP and HR) may have implications for cardiovascular disease risk given that sympathetic arousal is a mechanism implicated in this risk among PTSD populations. Future research examining differential pathways between PTSD and cardiovascular risk among men versus women is warranted.

Sex differences in post-traumatic stress disorder risk: autonomic control and inflammation

AIM

Over 7 million U.S. adults and about 20% of the military population have post-traumatic stress disorder (PTSD), a debilitating condition that is independently linked to a significantly greater risk of developing cardiovascular disease (CVD). Women have twice the probability of developing PTSD after experiencing a traumatic event compared to men. Existing literatures have reported higher inflammation and autonomic dysfunction including impaired baroreflex sensitivity, increased sympathetic reactivity and decreased parasympathetic activity in PTSD. However, most of these findings stem from studies conducted predominantly in males.

METHODS

We attempt in this narrative review to summarize the mixed literature available on sex differences in autonomic dysfunction and inflammation in PTSD, at rest and in response to stress in PTSD.

RESULTS

This review reveals that there is a paucity of research exploring autonomic function in females with PTSD. Recent studies have included female participants without probing for sex differences. A small number of studies have been conducted exclusively in women. Available data suggest that sympathetic nervous system output tends to be heightened, while parasympathetic activity and arterial baroreflex sensitivity appear more blunted in females with PTSD. Although few studies have investigated sex differences in inflammation in PTSD, data within females suggest chronic increases in inflammation with PTSD. This autonomic dysregulation and inflammation have also been described in males with PTSD.

CONCLUSION

In sum, given the inherent biological differences in CVD clinical presentation and characteristics between men and women, human and animal studies aiming at elucidating sex differences in the pathophysiology of PTSD are needed.

Nervous and Endocrine System Dysfunction in Posttraumatic Stress Disorder: An Overview and Consideration of Sex as a Biological Variable

Decades of research into the biological mechanisms of posttraumatic stress disorder (PTSD) suggests that chronic activation of the stress response leads to long-lasting changes in the structure and function of the nervous and endocrine systems. While the prevalence of PTSD is twice as high in females as males, little is known about how sex differences in neuroendocrine systems may contribute to PTSD. In response to the paucity of research on sex-related mechanisms, the National Institutes of Health created a policy that asks researchers to consider sex as a biological variable. This review provides an overview of the current understanding of nervous and endocrine dysfunction in PTSD (e.g., neural circuitry, autonomic arousal, hormonal response), highlighting areas where the influence of sex has been characterized and where further research is needed. We also provide recommendations for using the sex-as-a-biological-variable policy to address specific gaps in PTSD neuroscience research.

Distress tolerance: Associations with trauma and substance cue reactivity in low-income, inner-city adults with substance use disorders and posttraumatic stress

Cue reactivity has great potential to advance our understanding of posttraumatic stress disorder (PTSD), substance use disorder (SUD), and PTSD/SUD comorbidity. The present investigation examined distress tolerance (DT) with regard to trauma and substance cue reactivity. Participants included 58 low-income, inner-city adults (49.1% women; M_age = 45.73, SD = 10.00) with substance dependence and at least 4 symptoms of PTSD. A script-driven cue reactivity paradigm was utilized. Four DT measures were administered, including the Distress Tolerance Scale (DTS), Mirror-Tracing Persistence Task (MTPT), Breath-Holding Task (BH), and Paced Auditory Serial Addition Task (PASAT). Lower DT, as indexed by MTPT duration, was significantly predictive of greater levels of self-reported substance cravings/urges in response to trauma cues, above and beyond covariates. Lower DTS scores predicted lower levels of self-reported control/safety ratings in response to substance cues. None of the DT indices was significantly predictive of heart rate variability. Clinical and research implications are discussed. (PsycINFO Database Record

Skin Conductance Reactivity to Standardized Virtual Reality Combat Scenes in Veterans with PTSD

Interest in virtual reality (VR) as a clinical tool to augment posttraumatic stress (PTSD) treatment has grown substantially in recent years due to advances in VR technology. Moreover, its potential assisted use in the PTSD diagnostic process has been recognized. In this study we examined physiological responding, skin conductance, to a standardized presentation of non-personalized combat-related VR events (e.g. encountering enemy fire; explosions) as compared to non-combat classroom VR events in 19 Veterans with and 24 Veterans without combat-related PTSD who had been deployed to Iraq and Afghanistan. Veterans watched a total of 12 VR scenarios-six combat-related and six non-combat-related-with each scenario gradually increasing in emotional intensity by adding more VR events in addition to repeating prior VR events. Results show that Veterans with PTSD displayed larger skin conductance reactivity across VR combat events, but not for non-combat VR events, as compared to combat Veterans without PTSD. Nevertheless, Veterans with and without PTSD showed a similar reduction of emotional arousal to repeated presentation of the same VR combat events. Within the PTSD sample, the elevated level of VR combat-related arousal correlated marginally with severity of hyperarousal symptoms. This study confirms that the use of a non-personalized and standardized VR presentation successfully distinguishes Veterans with PTSD from those without on a measure of psychophysiological arousal to combat-related VR stimuli. The assessment of physiological reactivity during the repeated presentation of standardized, trauma-related VR events highlights its use for PTSD assessment as well as treatment.

Post-Traumatic Stress Disorder and Heart Failure in Men Within the Veteran Affairs Health System

Patients with post-traumatic stress disorder (PTSD) are at risk of multiple co-morbidities and are more likely to develop incident heart failure with reduced ejection fraction (HFrEF). The relation of PTSD with clinical outcomes in HFrEF is not established. US veterans diagnosed with HFrEF from January 2007 to January 2015 and treated nationwide in the Veterans Affairs (VA) Health System were included in the study. Patients with HFrEF were identified through International Classification of Diseases, Ninth Revision (ICD-9) codes. Mortality data were obtained from the VA's death registry. We compared characteristics of patients with HFrEF with and without PTSD. We identified 111,970 VA patients with HFrEF and 11,039 patients with concomitant PTSD (9.9%). Patients with PTSD and HFrEF tended to be younger (64 vs 69 years) and have a higher rate of coronary artery disease (73% vs 64%), chronic obstructive pulmonary disease (42% vs 31%), and hypertension (80% vs 64%, p <0.01 for all variables). Patients with PTSD and HFrEF were more commonly on a high-dose β blocker (70% vs 68%, p <0.01) and angiotensin-converting enzyme inhibitors (96% vs 93%, p <0.01). PTSD was associated with significantly increased mortality at 7 years compared with patients with heart failure without PTSD (adjusted 1.54, 95% confidence interval 1.30 to 1.82, p <0.01). In conclusion, nearly 10% of veterans with HFrEF have PTSD. Patients with HFrEF with PTSD have a higher burden of co-morbidities, and PTSD is associated with a higher rate of all-cause death. Our findings support greater attention to the treatment of patients with PTSD and the causes associated with the poor outcomes.

Prospectively predicting PTSD status with heart rate reactivity and recovery in interpersonal violence survivors

The current study used heart rate (HR) reactivity to personalized trauma cues and HR recovery to predict later Posttraumatic Stress Disorder (PTSD) status in female interpersonal violence survivors. A scripted imagery paradigm was used to assess initial (M = 1 month posttrauma) HR reactivity during exposure to and recovery following idiographic trauma cues. In addition, follow-up PTSD status (M = 8 months posttrauma) was assessed with the Clinician Administered PTSD scale (CAPS). A logistic regression was used to predict PTSD status at the follow-up assessment with HR reactivity during exposure to a personalized trauma audio script and recovery periods at initial assessment entered hierarchically. Script HR reactivity alone did not significantly predict PTSD status. However, after adding HR recovery, the model was significant. Higher HR during recovery was significantly positively associated with PTSD-positive status while script HR reactivity remained a non-significant predictor. The model correctly classified 70% of cases with PTSD. A second logistic regression with initial CAPS severity as a covariate showed that HR recovery added predictive value beyond acute PTSD symptoms. These results suggest that HR recovery following trauma cue exposure is an important predictor of PTSD development.

Early Linguistic Markers of Trauma-Specific Processing Predict Post-trauma Adjustment

Identifying early predictors for psychiatric disorders, such as post-traumatic stress disorder (PTSD), is crucial for effective treatment and prevention efforts. Obtaining such predictors is challenging and methodologically limited, for example by individuals' distress, arousal, and reduced introspective ability. We investigated the predictive power of language-based, implicit markers of psychological processes (N = 163) derived from computerized text-analysis of trauma and control narratives provided within 18 days post-trauma. Trauma narratives with fewer cognitive processing words (indicating less cognitive elaboration), more death-related words (indicating perceived threat to life), and more first-person singular pronouns (indicating self-immersed processing) predicted greater PTSD symptoms at 6 months. These effects were specific to trauma narratives and held after controlling for early PTSD symptom severity and verbal intelligence. When self-report questionnaires of related processes were considered together with the trauma narrative linguistic predictors, use of more first-person singular pronouns remained a significant predictor alongside self-reported mental defeat. Language-based processing markers may complement questionnaire measures in early forecasting of post-trauma adjustment.

Efficacy of Using Heart Rate Measurements as an Indicator to Monitor Anxiety Disorders: A Scoping Literature Review

Post-traumatic stress disorder (PTSD) is a prevalent disorder affecting veterans, first responders, children and others who have experienced traumatic events. Heart rate measures like resting heart rates along with heart rate accelerations are important measures to monitor the changes in the state of PTSD and other related disorders. A scoping review was conducted to investigate the efficacy of using heart rate (HR) measurements as reliable indicator for assessment of PTSD and other anxiety-related disorders. Findings show that while Heart Rate Variability (HRV) may provide a more robust measurement of PTSD and other anxiety-related symptoms, heart rate accelerations in response to traumatic reminders are reliable indicators. Changes in resting or basal heart rates show promise in long-term monitoring of PTSD symptoms.

Updating versus Exposure to Prevent Consolidation of Conditioned Fear

Targeting the consolidation of fear memories following trauma may offer a promising method for preventing the development of flashbacks and other unwanted re-experiencing symptoms that characterise Posttraumatic Stress Disorder (PTSD). Research has demonstrated that performing visuo-spatial tasks after analogue trauma can block the consolidation of fear memory and reduce the frequency of flashbacks. However, no research has yet used verbal techniques to alter memories during the consolidation window. This is surprising given that the most effective treatments for PTSD are verbally-based with exposure therapy and trauma-focused cognitive behavioural therapy gaining the most evidence of efficacy. Psychological therapies aim to reduce the conditioned fear response, which is in keeping with the preliminary finding that an increased propensity for fear conditioning may be a vulnerability factor for PTSD. Our research had two aims. We investigated the degree to which individual differences in fear conditioning predict the development of PTSD symptoms. We also compared the preventative effects of two clinically informed psychological techniques administered during the consolidation window: exposure to the trauma memory and updating the meaning of the trauma. 115 healthy participants underwent a fear conditioning paradigm in which traumatic film stimuli (unconditioned stimuli) were paired with neutral stimuli (conditioned stimuli). Participants were randomly allocated to an updating, exposure or control group to compare the effects on the conditioned fear response and on PTSD symptomatology. The results showed that stronger conditioned responses at acquisition significantly predicted the development of PTSD symptoms. The updating group, who verbally devalued the unconditioned stimulus within the consolidation window, experienced significantly lower levels of PTSD symptoms during follow-up than the exposure and control groups. These findings are consistent with clinical interventions for chronic PTSD and have important implications for identifying those at risk as well as for designing novel early interventions to prevent the development of PTSD.

Systems biology approach to understanding post-traumatic stress disorder

This review paper presents known biological facts about PTSD and the mathematical/systems biology tools used to understand the underpinning molecular principles.

The ethics of distress: toward a framework for determining the ethical acceptability of distressing health promotion advertising

Distressing health promotion advertising involves the elicitation of negative emotion to increase the likelihood that health messages will stimulate audience members to adopt healthier behaviors. Irrespective of its effectiveness, distressing advertising risks harming audience members who do not consent to the intervention and are unable to withdraw from it. Further, the use of these approaches may increase the potential for unfairness or stigmatization toward those targeted, or be considered unacceptable by some sections of the public. We acknowledge and discuss these concerns, but, using the public health ethics literature as a guide, argue that distressing advertising can be ethically defensible if conditions of effectiveness, proportionality necessity, least infringement, and public accountability are satisfied. We do not take a broad view as to whether distressing advertising is ethical or unethical, because we see the evidence for both the effectiveness of distressing approaches and their potential to generate iatrogenic effects to be inconclusive. However, we believe it possible to use the current evidence base to make informed estimates of the likely consequences of specific message presentations. Messages can be pre-tested and monitored to identify and deal with potential problems. We discuss how advertisers can approach the problems of deciding on the appropriate intensity of ethical review, and evaluating prospective distressing advertising campaigns against the conditions outlined.

Brain activation and heart rate during script-driven traumatic imagery in PTSD: preliminary findings

Patients with posttraumatic stress disorder (PTSD) experience psychological and physiological distress. However, imaging research has mostly focused on the psychological aspects of the disorder. Considered an expression of distress, heart rate (HR) in PTSD is often elevated. In the current study, we sought to identify brain regions associated with increased HR in PTSD. Nine patients with PTSD and six healthy trauma survivors were scanned while resting, clenching teeth, and listening to neutral and traumatic scripts. Brain function was evaluated using H2O15 positron emission tomography (PET). HR was monitored by electrocardiogram. Data were analyzed using statistical parametric mapping (SPM). Subjects with PTSD exhibited a significant increase in HR upon exposure to traumatic scripts, while trauma survivors did not. Correlations between regional cerebral blood flow and HR were found only in patients with PTSD, in orbitofrontal, precentral and occipital regions. Neither group showed correlation between rCBF and HR in the amygdala or hippocampus. These preliminary results indicate that "top down" central nervous system regulation of autonomic stress response in PTSD may involve associative, sensory and motor areas in addition to regions commonly implicated in fear conditioning.

Biological studies of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is the only major mental disorder for which a cause is considered to be known: that is, an event that involves threat to the physical integrity of oneself or others and induces a response of intense fear, helplessness or horror. Although PTSD is still largely regarded as a psychological phenomenon, over the past three decades the growth of the biological PTSD literature has been explosive, and thousands of references now exist. Ultimately, the impact of an environmental event, such as a psychological trauma, must be understood at organic, cellular and molecular levels. This Review attempts to present the current state of this understanding on the basis of psychophysiological, structural and functional neuroimaging, and endocrinological, genetic and molecular biological studies in humans and in animal models.

Dark-enhanced startle responses and heart rate variability in a traumatized civilian sample: putative sex-specific correlates of posttraumatic stress disorder

OBJECTIVE

Trauma is associated with increased risk for anxiety disorders such as posttraumatic stress disorder (PTSD). To further understand biologic mechanisms of PTSD, we examined the dark-enhanced startle response, a psychophysiological correlate of anxiety, and heart rate variability (HRV) in traumatized individuals with and without PTSD. The associations of these measures with PTSD may be sex-specific because of their associations with the bed nucleus of the stria terminalis, a sexually dimorphic brain structure in the limbic system that is approximately 2.5 times larger in men than in women.

METHODS

The study sample (N = 141) was recruited from a highly traumatized civilian population seeking treatment at Grady Memorial Hospital in Atlanta, Georgia. Psychophysiological responses during a dark-enhanced startle paradigm task included startle magnitude, assessed by eyeblink reflex, and measures of high-frequency HRV, during light and dark phases of the startle session.

RESULTS

The startle magnitude was higher during the dark phase than the light phase (mean ± standard error = 98.61 ± 10.68 versus 73.93 ± 8.21 μV, p < .001). PTSD was associated with a greater degree of dark-enhanced startle in women (p = .03) but not in men (p = .38, p interaction = .48). Although HRV measures did not differ between phases, high-frequency HRV was greater in men with PTSD compared with men without PTSD (p = .02).

CONCLUSIONS

This study demonstrates that the dark-enhanced paradigm provides novel insights into the psychophysiological responses associated with PTSD in traumatized civilian sample. Sex differences in altered parasympathetic and sympathetic function during anxiety regulation tasks may provide further insight into the neurobiological mechanisms of PTSD.

Post-traumatic Stress Disorder and Cardiovascular Disease

This review provides an up-to-date summary of the evidence from clinical and epidemiologic studies indicating that persons with post-traumatic stress disorder (PTSD) may have an increased risk of coronary heart disease and possibly thromboembolic stroke. Persons with PTSD, a common anxiety disorder in both veteran and nonveteran populations, have been reported to have an increased risk of hypertension, hyperlipidemia, obesity, and cardiovascular disease. Increased activity of the sympathoadrenal axis may contribute to cardiovascular disease through the effects of catecholamines on the heart, vasculature, and platelet function. Reported links between PTSD and hypertension and other cardiovascular risk factors may partly account for reported associations between PTSD and heart disease. The associations observed between PTSD and cardiovascular diseases have implications for cardiology practice and research.