Effects of Daily Posttraumatic Stress Disorder Symptoms on Heart Rate Variability.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is common, debilitating, and associated with an increased risk of health problems, including cardiovascular disease. PTSD is related to poor autonomic function indicated by reduced heart rate variability (HRV). However, very little work has tested the timescale or direction of these effects, given that most evidence comes from cross-sectional studies. Documentation of when effects occur and in what direction can shed light on mechanisms of cardiovascular disease risk and inform treatment. The present study of 169 World Trade Center responders, oversampled for PTSD, tested how daily PTSD symptoms were associated with autonomic function as reflected through HRV. METHODS: Participants ( N = 169) completed surveys of PTSD symptoms three times a day at 5-hour intervals for 4 days while also wearing ambulatory monitors to record electrocardiograms to derive HRV (i.e., mean absolute value of successive differences between beat-to-beat intervals). RESULTS: HRV did not predict PTSD symptoms. However, PTSD symptoms during a 5-hour interval predicted reduced HRV at the next 5-hour interval ( ß = -0.09, 95% confidence interval = -0.16 to -0.02, p = .008). Results held adjusting for baseline age, current heart problems, and current PTSD diagnosis. CONCLUSIONS: Findings underscore growing awareness that PTSD symptoms are not static. Even their short-term fluctuations may affect cardiovascular functioning, which could have more severe impacts if disruption accumulates over time. Research is needed to determine if momentary interventions can halt increases in PTSD symptoms or mitigate their impact on cardiovascular health.

Alcohol Use Predicts Longer But More Fragmented Sleep: A Daily Diary Study of Alcohol, Sleep, and PTSD in Nurses.

BACKGROUND: Due to the demanding nature of their profession, nurses are at risk of experiencing irregular sleep patterns, substance use, and fatigue. Evidence supports a reciprocal relationship between alcohol use and sleep disturbances; however, no research has examined such a link in a sample of nurses. One factor that may further impact the dynamic between alcohol and sleep patterns is posttraumatic stress disorder (PTSD) symptoms. We investigated the daily bidirectional associations between alcohol use and several sleep domains (i.e., self-report and actigraphy-determined sleep), and moderation by baseline PTSD symptom severity. METHOD: Over a 14-day period, 392 nurses (92% female; 78% White) completed sleep diaries and actigraphy to assess alcohol use and sleep patterns. Within-person bidirectional associations between alcohol and sleep were examined using multilevel models, with symptoms of PTSD as a cross-level moderator. RESULTS: Daily alcohol use (i.e., ≥ 1 alcoholic beverage; 25.76%) was associated with shorter self-reported sleep onset latency (b = -4.21, p = .003) but longer self-reported wake after sleep onset (b = 2.36, p = .009). Additionally, days with any alcohol use were associated with longer self-reported sleep duration (b = 15.60, p = .006) and actigraphy-determined sleep duration (b = 10.06, p = .037). No sleep variables were associated with next-day alcohol use. Bidirectional associations between alcohol consumption and sleep were similar regardless of baseline PTSD symptoms. CONCLUSION: Our results suggested that on days when nurses drank alcohol, they experienced longer but also more fragmented sleep.

Psychometric Evaluation of the Insomnia Severity Index in Nurses.

OBJECTIVES: Examine psychometric properties of the Insomnia Severity Index (ISI) in a sample of nurses. METHOD: In a sample of day shift nurses (N = 289), a confirmatory factor analysis (CFA), convergent and discriminant validity analyses, and a test-retest reliability analysis were performed. RESULTS: CFA showed that a two-factor model provided the best fit. The ISI had moderate to poor convergent validity with sleep diary parameters, and moderate convergent validity with the Sleep Condition Indicator (r = -.66), Pittsburgh Sleep Quality Index (r = .66), and PROMIS Sleep-Related Impairment measure (r = .67). The ISI demonstrated good discriminant validity with the measures Composite Scale of Morningness (r = -.27), Nightmares Disorder Index (r = .25), PTSD Checklist for DSM-5 (sleep items removed; r = .32), and Perceived Stress Scale (r = .43). The ISI had weaker discriminant validity with the PHQ-9 (r = .69) and Generalized Anxiety Disorder Screener (r = .51). The ISI demonstrated a good test-retest reliability (ICCs = .74-.88). CONCLUSIONS: The ISI is a psychometrically strong measure for the assessment of insomnia severity in day shift nurses. Overlap with psychological symptoms, primarily anxiety and depression, suggests caution while interpreting these constructs.

Daily Sleep-Stress Reactivity and Functional Impairment in World Trade Center Responders.

BACKGROUND: How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that predict depression, anxiety, and insomnia. However, pathways between reactivity and functional impairment (e.g., impairment in social relationships and interpersonal functioning) have not been explored, which may be a critical pathway in understanding the link between reactivity and the development of psychological disorders. PURPOSE: We examined associations between reactivity and changes in functional impairment among a cohort of 9/11 World Trade Center responders. METHODS: Data from 452 responders (Mage = 55.22 years; 89.4% male) were collected between 2014 and 2016. Four baseline sleep and stress reactivity indices (i.e., sleep duration and efficiency reactivity to stress; stress reactivity to sleep duration and efficiency) were calculated from 14 days of sleep and stress data using random slopes from multilevel models. Functional impairment was assessed approximately 1 year and 2 years after baseline via semi-structured interviews. Latent change score analyses examined associations between baseline reactivity indices and changes in functional impairment. RESULTS: Greater baseline sleep efficiency reactivity to stress was associated with decreases in functioning (ß = -0.05, p = .039). In addition, greater stress reactivity to sleep duration (ß = -0.08, p = .017) and sleep efficiency (ß = -0.22, p < .001) was associated with lower functioning at timepoint one. CONCLUSION: People who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high reactivity who could benefit from preventative treatment may foster better social integration.

How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that may contribute to an individual's risk of developing of psychological disorders, such as depression, anxiety, and insomnia. It is possible that individuals with high sleep-stress reactivity are more likely to experience long-term functional impairment (e.g., impairment in social relationships and interpersonal functioning)­a predisposing factor for psychological disorders, yet this pathway has not been explored. Therefore, we examined associations between sleep-stress reactivity and changes in functional impairment across a 1-year period in a large sample of 9/11 World Trade Center responders. The study results suggest that 9/11 World Trade Center responders who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high sleep-stress reactivity who could benefit from preventative treatment may foster better social integration.

The Hierarchical Taxonomy of Psychopathology (HiTOP) in psychiatric practice and research.

The Hierarchical Taxonomy of Psychopathology (HiTOP) has emerged out of the quantitative approach to psychiatric nosology. This approach identifies psychopathology constructs based on patterns of co-variation among signs and symptoms. The initial HiTOP model, which was published in 2017, is based on a large literature that spans decades of research. HiTOP is a living model that undergoes revision as new data become available. Here we discuss advantages and practical considerations of using this system in psychiatric practice and research. We especially highlight limitations of HiTOP and ongoing efforts to address them. We describe differences and similarities between HiTOP and existing diagnostic systems. Next, we review the types of evidence that informed development of HiTOP, including populations in which it has been studied and data on its validity. The paper also describes how HiTOP can facilitate research on genetic and environmental causes of psychopathology as well as the search for neurobiologic mechanisms and novel treatments. Furthermore, we consider implications for public health programs and prevention of mental disorders. We also review data on clinical utility and illustrate clinical application of HiTOP. Importantly, the model is based on measures and practices that are already used widely in clinical settings. HiTOP offers a way to organize and formalize these techniques. This model already can contribute to progress in psychiatry and complement traditional nosologies. Moreover, HiTOP seeks to facilitate research on linkages between phenotypes and biological processes, which may enable construction of a system that encompasses both biomarkers and precise clinical description.

Daily stress and sleep associations vary by work schedule: A between- and within-person analysis in nurses.

Nurses experience poor sleep and high stress due to demanding work environments. Night shift work is common among nurses and may exacerbate stress-sleep associations. We examined bidirectional associations between daily stress and sleep, and moderation by recent shift worker status and daily work schedule among nurses. Participants were 392 nurses (92% female; 78% White, mean age = 39.54, SD = 11.15) who completed 14 days of electronic sleep diaries and actigraphy. They simultaneously completed assessments of daily stress and work schedule upon awakening (day shift vs. night shift [work between 9 p.m.-6 a.m.] vs. off work). Participants were classified as recent night shift workers if they worked at least one night shift during the past 14 days (n = 101; 26%). In the entire sample, greater daily stress predicted shorter self-reported total sleep time and lower self-reported sleep efficiency that night. Shorter self-reported and actigraphy total sleep time and lower self-reported sleep efficiency predicted higher next-day stress. Compared with recent night shift workers, day workers reported higher stress after nights with shorter total sleep time. Stress-sleep associations mostly did not vary by nurses' daily work schedule. Sleep disturbances and stress may unfold in a toxic cycle and are prime targets for tailored interventions among nurses. Night shift workers may be less susceptible to the effects of short sleep on next-day stress. Research is needed to understand the short- and long-term effects of shift work and address the unique sleep challenges nurses face.

Anxiety sensitivity and Pain Experience: a prospective investigation among World Trade Center Responders.

Chronic pain is a significant public health problem and is exacerbated by stress. The World Trade Center (WTC) Disaster represents a unique stressor, and responders to the WTC disaster are at increased risk for pain and other health complaints. Therefore, there is a significant need to identify vulnerability factors for exacerbated pain experience among this high-risk population. Anxiety sensitivity (AS), defined as fear of anxiety-related sensations, is one such vulnerability factor associated with pain intensity and disability. Yet, no work has tested the predictive effects of AS on pain, limiting conclusions regarding the predictive utility and direction of associations. Therefore, the current study examined the prospective associations of AS, pain intensity, and pain interference among 452 (Mage = 55.22, SD = 8.73, 89.4% male) responders to the WTC disaster completing a 2-week daily diary study. Using multi-level modeling, AS total score was positively associated with both pain intensity and pain interference, and that AS cognitive concerns, but not social or physical concerns, were associated with increased pain. These results highlight the importance of AS as a predictor of pain complaints among WTC responders and provide initial empirical evidence to support AS as a clinical target for treating pain complaints among WTC responders.

Racial/ethnic variations in inflammatory markers: exploring the role of sleep duration and sleep efficiency.

Individuals from minoritized racial/ethnic groups have higher levels of circulating inflammatory markers. However, the mechanisms underlying these differences remain understudied. The objective of this study was to examine racial/ethnic variations in multiple markers of inflammation and whether impaired sleep contributes to these racial/ethnic differences. Nurses from two regional hospitals in Texas (n = 377; 71.62% White; 6.90% Black; 11.14% Hispanic, 10.34% Asian; mean age = 39.46; 91.78% female) completed seven days of sleep diaries and actigraphy to assess mean and variability in total sleep time (TST) and sleep efficiency (SE). On day 7, blood was drawn to assess 4 inflammatory markers: C-reactive protein (CRP), Interleukin-6 (IL-6), Interleukin-1 beta (IL-1ß), and tumor necrosis factor-alpha (TNF-α). Results from regression models showed differences in inflammatory markers by race/ethnicity, adjusting for age and gender. The associations between sleep parameters and inflammatory markers also varied by race/ethnicity. Among White nurses, lower mean and greater variability in actigraphy-determined TST and greater variability in diary-determined TST were associated with higher levels of IL-6. Among Black nurses, lower mean diary-determined SE was associated with higher levels of IL-6 and IL-1ß. Among Hispanic nurses, greater diary-determined mean TST was associated with higher CRP. Among Asian nurses, greater intraindividual variability in actigraphy-determined SE was associated with lower CRP. Among nurses, we did not find racial/ethnic disparities in levels of inflammation. However, analyses revealed differential relationships between sleep and inflammatory markers by race/ethnicity. Results highlight the importance of using a within-group approach to understand predictors of inflammatory markers.

Characterizing Patterns of Nurses' Daily Sleep Health: a Latent Profile Analysis.

BACKGROUND: Nursing is a demanding occupation characterized by dramatic sleep disruptions. Yet most studies on nurses' sleep treat sleep disturbances as a homogenous construct and do not use daily measures to address recall biases. Using person-centered analyses, we examined heterogeneity in nurses' daily sleep patterns in relation to psychological and physical health. METHODS: Nurses (N = 392; 92% female, mean age = 39.54 years) completed 14 daily sleep diaries to assess sleep duration, efficiency, quality, and nightmare severity, as well as measures of psychological functioning and a blood draw to assess inflammatory markers interleukin-6 (IL-6) and C-reactive protein (CRP). Using recommended fit indices and a 3-step approach, latent profile analysis was used to identify the best-fitting class solution. RESULTS: The best-fitting solution suggested three classes: (1) "Poor Overall Sleep" (11.2%), (2) "Nightmares Only" (8.4%), (3) "Good Overall Sleep" (80.4%). Compared to nurses in the Good Overall Sleep class, nurses in the Poor Overall Sleep or Nightmares Only classes were more likely to be shift workers and had greater stress, PTSD symptoms, depression, anxiety, and insomnia severity. In multivariate models, every one-unit increase in insomnia severity and IL-6 was associated with a 33% and a 21% increase in the odds of being in the Poor Overall Sleep compared to the Good Overall Sleep class, respectively. CONCLUSION: Nurses with more severe and diverse sleep disturbances experience worse health and may be in greatest need of sleep-related and other clinical interventions.

Commentary- Opening a can of worms: the importance of testing the measurement invariance of hierarchical models of psychopathology - a commentary on He and Li (2020).

Measurement invariance is an understudied topic in much of psychopathology research, but its effects have far-reaching consequences. It has rarely been examined with respect to hierarchical models of psychopathology. He & Li's (2020) study represents one of the first attempts to bridge the gap between relatively narrow focused studies on the psychometric properties of specific assessments with broader research on the hierarchical structure of psychopathology. The results are promising, but more research is needed to understand the impact of culture, race, and ethnicity on the expression of psychopathology. Future research may determine whether dimensional and hierarchical models decrease the effect of cultural biases on assessment and help to further understand the etiology of epidemiological differences in rates of disorders. These models may also help to account for culture-bound syndromes.