Reduced hippocampal volume is frequently observed in posttraumatic stress disorder (PTSD), but the psychological processes associated with these alterations remain unclear. Given hippocampal involvement in memory and contextual representations of threat, we investigated relationships between retrospectively reported combat exposure, perceived threat, and hippocampal volume in trauma-exposed veterans. T1-weighted anatomical MRI scans were obtained from 56 veterans (4 women, 52 men; 39 with elevated PTSD symptoms, “PTSS” group) and hippocampal volume was estimated using automatic segmentation tools in FreeSurfer. Hippocampal volume was regressed on self-reported perceived threat from the Deployment Risk and Resilience Inventory, and combat exposure from the Combat Exposure Scale. As a secondary analysis, hippocampal volume was regressed on Clinician-Administered PTSD Scale (CAPS) symptoms. In veterans with elevated PTSD symptoms, hippocampal volume was inversely related to perceived threat while deployed while controlling for self-reported combat exposure. Hippocampal volume was also inversely correlated with avoidance/numbing CAPS symptoms. Future research should clarify the temporal milieu of these effects and investigate whether individual differences in hippocampal structure and function contribute to heightened threat appraisal at the time of trauma vs. subsequently elevated appraisals of traumatic events.
Previous studies have identified reduced heart rate variability (HRV) in post‐traumatic stress disorder (PTSD), which may temporally precede the onset of the disorder. A separate line of functional neuroimaging research in PTSD has consistently demonstrated hypoactivation of the ventromedial prefrontal cortex (vmPFC), a key aspect of a descending neuromodulatory system that exerts inhibitory control over heart rate. No research to date, however, has simultaneously investigated whether altered vmPFC activation is associated with reduced HRV and elevated PTSD symptoms in the same individuals. Here, we collected fMRI data during alternating conditions of threat of shock and safety from shock in 51 male combat‐exposed veterans with either high or low levels of PTSD symptoms. Pulse rate variability (PRV)—a HRV surrogate calculated from pulse oximetry—was assessed during a subsequent resting scan. Correlational analyses tested for hypothesized relationships between reduced vmPFC activation, lower PRV, and elevated PTSD symptomatology. We found that PTSD re‐experiencing symptoms were inversely associated with high‐frequency (HF)‐PRV, thought to primarily reflect parasympathetic control of heart rate, in veterans with elevated PTSD symptoms. Reduced vmPFC activation for the contrast of safety‐threat was associated both with lower HF‐PRV and elevated PTSD re‐experiencing symptoms. These results tie together previous observations of reduced HRV/PRV and impaired vmPFC function in PTSD and call for further research on reciprocal brain‐body relationships in understanding PTSD pathophysiology.
more » « less- PAR ID:
- 10459846
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Psychophysiology
- Volume:
- 57
- Issue:
- 1
- ISSN:
- 0048-5772
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract -
more » « less
Abstract Post‐traumatic stress disorder (PTSD) is an independent risk factor for incident heart failure, but the underlying cardiac mechanisms remained elusive. Impedance cardiography (ICG), especially when measured during stress, can help understand the underlying psychophysiological pathways linking PTSD with heart failure. We investigated the association between PTSD and ICG‐based contractility metrics (pre‐ejection period (PEP) and Heather index (HI)) using a controlled twin study design with a laboratory‐based traumatic reminder stressor. PTSD status was assessed using structured clinical interviews. We acquired synchronized electrocardiograms and ICG data while playing personalized‐trauma scripts. Using linear mixed‐effects models, we examined twins as individuals and within PTSD‐discordant pairs. We studied 137 male veterans (48 pairs, 41 unpaired singles) from Vietnam War Era with a mean (standard deviation) age of 68.5(2.5) years. HI during trauma stress was lower in the PTSD vs. non‐PTSD individuals (7.2 vs. 9.3 [ohm/s2],
p = .003). PEP reactivity (trauma minus neutral) was also more negative in PTSD vs. non‐PTSD individuals (−7.4 vs. −2.0 [ms],p = .009). The HI and PEP associations with PTSD persisted for adjusted models during trauma and reactivity, respectively. For within‐pair analysis of eight PTSD‐discordant twin pairs (out of 48 pairs), PTSD was associated with lower HI in neutral, trauma, and reactivity, whereas no association was found between PTSD and PEP. PTSD was associated with reduced HI and PEP, especially with trauma recall stress. This combination of increased sympathetic activation and decreased cardiac contractility combined may be concerning for increased heart failure risk after recurrent trauma re‐experiencing in PTSD. -
null (Ed.)Emotion-driven impulse control difficulties are associated with negative psychological outcomes. Extant research suggests that high-frequency heart rate variability (HF-HRV) may be indicative of emotion-driven impulse control difficulties and potentially moderated by negative emotion. In the current study, 248 eleven- to 14-year-olds and their parent engaged in a negatively emotionally arousing conflict task at Time 1. Adolescents’ HF-HRV and negative emotional expression and experience were assessed before, during, and/or after the task. Adolescents reported on their levels of emotion-driven impulse control difficulties at Time 1 and one year later. Results revealed that higher levels of HF-HRV reactivity (i.e., higher HF-HRV augmentation) predicted higher levels of emotion-driven impulse control difficulties 1 year later among adolescents who experienced higher negative emotion. These findings suggest that negative emotional context should be considered when examining HF-HRV reactivity as a risk factor for emotion-driven impulse control difficulties and associated outcomes.more » « less
-
more » « less
Abstract The current study investigated high‐frequency heart rate variability (HF‐HRV) as a potential mediator between childhood parental warmth and later health and mortality outcomes. Participants were 1,255 adults (56.9% female). Childhood parental warmth was reported retrospectively at mean age 46; resting HF‐HRV was measured at mean age 57; cardiovascular health and self‐evaluated health were assessed at mean ages 57 and 63, and mortality records extracted at mean age 63. Results revealed a positive association between childhood parental warmth and resting HF‐HRV, as well as associations between higher HF‐HRV and reduced risk of having a later cardiovascular health problem and of mortality by age 63. Mediation analyses revealed a small significant indirect effect of parental warmth, through HF‐HRV, on cardiovascular health.
-
more » « less
Abstract Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) commonly co‐occur in combat veterans, and this comorbidity has been associated with higher levels of distress and more social and economic costs compared to one disorder alone. In a secondary analysis of a multisite randomized controlled trial of a sample of veterans with combat‐related PTSD, we examined the associations among pre‐, peri‐, and postdeployment adversity, social support, and clinician‐diagnosed comorbid MDD. Participants completed the Deployment Risk and Resilience Inventory and the Beck Depression Inventory–II as well as structured clinical interviews for diagnostic status. Among 223 U.S. veterans of the military operations in Iraq and Afghanistan (86.9% male) with primary combat‐related PTSD, 69.5% had current comorbid MDD. After adjustment for sex, a linear regression model indicated that more concerns about family disruptions during deployment,
f 2= 0.065; more harassment during deployment,f 2= 0.020; and lower ratings of postdeployment social support,f 2= 0.154, were associated with more severe self‐reported depression symptoms. Interventions that enhance social support as well as societal efforts to foster successful postdeployment reintegration are critical for reducing the mental health burden associated with this highly prevalent comorbidity in veterans with combat‐related PTSD.
