Sleep duration and post-traumatic stress disorder symptoms: a twin study

Exposure to maternal experiences of IPV in early childhood and sleep health in adolescence

BACKGROUND

Half of US women will experience intimate partner violence (IPV), and nearly all children in families experiencing such violence will be exposed. The negative effects of IPV exposure on children's mental and physical health are well-documented; however, less is known about effects on children's sleep health, a key marker of well-being.

OBJECTIVE

This study examines the associations of early childhood exposure to maternal experiences of IPV with sleep health in adolescence, focusing on multiple dimensions of sleep health and differences by child sex.

PARTICIPANTS AND SETTING

We rely on data from the Future of Families and Child Wellbeing Study, a population-based study following 5000 children in large US cities, from birth to age 15. Analyses are based on 2687 adolescents interviewed at the year-15 follow-up.

METHODS

Early childhood exposure to IPV is based on mothers' reports of her experiences of IPV from the child's birth to age 5. Adolescent sleep health is measured using 6 items approximating the BEARS sleep problem scale, at age 15. We estimate multivariate linear regression models to examine associations of early childhood IPV exposure with adolescent sleep health and stratify models by child sex.

RESULTS

Early childhood IPV exposure is associated with worse overall sleep health (β = 0.08; p < 0.001) and multiple dimensions of poor sleep health in adolescence. Associations are notably stronger among girls than boys.

CONCLUSIONS

The strong and lasting associations of early childhood exposure to IPV with adolescents' sleep health, particularly among girls, has important consequences for addressing adolescent health disparities.

Post-traumatic stress disorder as a risk factor for major adverse cardiovascular events: a cohort study of a South African medical insurance scheme

AIMS

Prior research, largely focused on US male veterans, indicates an increased risk of cardiovascular disease among individuals with post-traumatic stress disorder (PTSD). Data from other settings and populations are scarce. The objective of this study is to examine PTSD as a risk factor for incident major adverse cardiovascular events (MACEs) in South Africa.

METHODS

We analysed reimbursement claims (2011-2020) of a cohort of South African medical insurance scheme beneficiaries aged 18 years or older. We calculated adjusted hazard ratios (aHRs) for associations between PTSD and MACEs using Cox proportional hazard models and calculated the effect of PTSD on MACEs using longitudinal targeted maximum likelihood estimation.

RESULTS

We followed 1,009,113 beneficiaries over a median of 3.0 years (IQR 1.1-6.0). During follow-up, 12,662 (1.3%) persons were diagnosed with PTSD and 39,255 (3.9%) had a MACE. After adjustment for sex, HIV status, age, population group, substance use disorders, psychotic disorders, major depressive disorder, sleep disorders and the use of antipsychotic medication, PTSD was associated with a 16% increase in the risk of MACEs (aHR 1.16, 95% confidence interval (CI) 1.05-1.28). The risk ratio for the effect of PTSD on MACEs decreased from 1.59 (95% CI 1.49-1.68) after 1 year of follow-up to 1.14 (95% CI 1.11-1.16) after 8 years of follow-up.

CONCLUSION

Our study provides empirical support for an increased risk of MACEs in males and females with PTSD from a general population sample in South Africa. These findings highlight the importance of monitoring cardiovascular risk among individuals diagnosed with PTSD.

Quasi-causal associations between chronotype and post-traumatic stress disorder symptoms: A twin study

OBJECTIVE

The evening ("night owl") chronotype is associated with greater severity and lifetime prevalence of post-traumatic stress disorder (PTSD) symptoms compared to morning or intermediate chronotypes. This twin study investigated the gene-environment relationships between chronotype, recent PTSD symptoms, and lifetime intrusive symptoms.

METHODS

We used the reduced Horne-Östberg Morningness-Eveningness Questionnaire (rMEQ) to assess chronotype in a sample of 3777 same-sex adult twin pairs raised together (70.4% monozygotic, 29.6% dizygotic) in the community-based Washington State Twin Registry. PTSD symptoms were reported on the Impact of Events Scale (IES) and a single item for lifetime experience of intrusive symptoms after a stressful or traumatic event.

RESULTS

Genetic influences accounted for 50% of chronotype variance, 30% of IES score variance, and 14% of lifetime intrusive symptom variance. Bivariate twin models showed a phenotypic association (b_p) between evening chronotype and more severe PTSD symptoms (b_p = -0.16, SE = 0.02, p < .001) that remained significant even after adjusting for shared genetic and environmental influences (b_p = -0.10, SE = 0.04, p = .009), as well as age, sex, and self-reported sleep duration (b_p = -0.11, SE = 0.04, p = .004). An association was found between evening chronotype and lifetime intrusive symptoms (b_p = -0.11, SE = 0.03, p < .001) that was no longer significant after adjusting for shared genetic and environmental influences (b_p = 0.04, SE = 0.06, p = .558).

CONCLUSIONS

Our results suggest a "quasi-causal" relationship between evening chronotype and PTSD symptoms that is not purely attributable to genetic or shared environmental factors. Evening chronotype may increase vulnerability to pathologic stress responses in the setting of circadian misalignment, providing potential avenues of prevention and treatment using chronobiological strategies.

The association between traumatic life events and insomnia symptoms among men and women: Results from the Baltimore Epidemiologic Catchment Area follow-up study

STUDY OBJECTIVES

Trauma exposure likely contributes to poor sleep, but relatively few studies have empirically tested this, instead focusing on posttraumatic stress disorder. Moreover, little is known about sex differences in sleep after trauma. The current study used a cross-sectional and retrospective design to test hypotheses that trauma exposure would be associated with subsequent insomnia symptoms, particularly among women, even after accounting for important covariates.

METHOD

Data from Wave 3 (1993-1996) of the Baltimore Epidemiologic Catchment Area Study (N = 1920) were used to examine associations between remote (prior to past year) and recent (past year) trauma and current sleep disturbance (insomnia, hypersomnia symptoms) in the total sample (Mage= 55, 63.2% women, 57.7% white), and separately in men and women. Sensitivity analyses were conducted among individuals with no pretrauma sleep disturbance to examine incident sleep disturbance.

RESULTS

Among all participants, both remote (odds ratio [OR] = 1.95, 95% confidence interval [CI] [1.34, 2.85]) and recent (OR = 1.94, 95% CI [1.31, 2.87]) trauma exposure were associated with increased odds of insomnia (OR = 2.41, 95% CI [1.54, 3.76]) but not hypersomnia. Associations between trauma and insomnia were particularly strong among women, but null among men. The relationship between trauma exposure and insomnia symptoms persisted among individuals with no pretrauma history of insomnia.

CONCLUSION

Results suggest women may be vulnerable to insomnia symptoms as sequelae of trauma. Future research should examine prospective associations between trauma and sleep in larger samples and how assessment and treatment of insomnia among women trauma survivors reduces the public health impact of trauma and poor sleep.

Posttraumatic stress disorder: from gene discovery to disease biology

Posttraumatic stress disorder (PTSD) is a complex mental disorder afflicting approximately 7% of the population. The diverse number of traumatic events and the wide array of symptom combinations leading to PTSD diagnosis contribute substantial heterogeneity to studies of the disorder. Genomic and complimentary-omic investigations have rapidly increased our understanding of the heritable risk for PTSD. In this review, we emphasize the contributions of genome-wide association, epigenome-wide association, transcriptomic, and neuroimaging studies to our understanding of PTSD etiology. We also discuss the shared risk between PTSD and other complex traits derived from studies of causal inference, co-expression, and brain morphological similarities. The investigations completed so far converge on stark contrasts in PTSD risk between sexes, partially attributed to sex-specific prevalence of traumatic experiences with high conditional risk of PTSD. To further understand PTSD biology, future studies should focus on detecting risk for PTSD while accounting for substantial cohort-level heterogeneity (e.g. civilian v. combat-exposed PTSD cases or PTSD risk among cases exposed to specific traumas), expanding ancestral diversity among study cohorts, and remaining cognizant of how these data influence social stigma associated with certain traumatic events among underrepresented minorities and/or high-risk populations.

Is COVID-19 Keeping us Up at Night? Stress, Anxiety, and Sleep Among Adult Twins

In response to the COVID-19 pandemic, a variety of social distancing measures to mitigate the virus outbreak have been implemented. These measures may have unintended consequences on individuals' well-being, such as increased stress, anxiety, and sleep disruptions. We investigated the extent to which individuals' mental health status is associated with perceived changes in sleep amount and sleep quality among a sample of adult twin pairs (N = 909 pairs; 77% MZ, 23% DZ), less than a month after the outbreak was declared a pandemic by the World Health Organization. About half of participants reported no change in sleep amount (50.1%) or sleep quality (55.6%). Approximately one-third of the participants had increased amount of sleep (29.8%), and 32.9% reported a decrease in sleep quality. We found that stress and anxiety levels were associated with sleep reduction (ORs = 2.36 and 3.12 for stress and anxiety, respectively) and poorer sleep quality (ORs = 2.45 and 3.73 for stress and anxiety, respectively), even after taking into account between-family confounds. A much smaller association was observed between levels of stress and anxiety and increased sleep amount (ORs = 1.42 and 1.60 for stress and anxiety, respectively) and sleep quality (OR = 1.21 and 1.29 for stress and anxiety, respectively), which was no longer significant after controlling for between-family confounds. Our results demonstrate that stress and anxiety associated with the COVID-19 pandemic and social distancing measures may be linked to reduced sleep amount and quality.

Reduced Sleep Duration and Sleep Efficiency Were Independently Associated With Frequent Nightmares in Chinese Frontline Medical Workers During the Coronavirus Disease 2019 Outbreak

Objectives

Nightmares were related to emotion and behavioral problems and also emerged as one of the core features of post-traumatic stress disorder (PTSD). Our study aimed to investigate the associations of frequent nightmares with sleep duration and sleep efficiency among frontline medical workers in Wuhan during the coronavirus disease 2019 (COVID-19) outbreak.

Methods

A total of 528 health-care workers from the province of Fujian providing medical aid in Wuhan completed the online questionnaires. There were 114 doctors and 414 nurses. The age, sex, marital status, and work situation were recorded. A battery of scales including the Pittsburgh Sleep Quality Index (PSQI) and the 12-item General Health Questionnaire (GHQ-12) were used to evaluate subjects’ sleep and general mental health. Frequent nightmares were defined as the response of at least once a week in the item of “nightmare” of PSQI.

Results

Frequent nightmares were found in 27.3% of subjects. The frequent nightmare group had a higher score of PSQI-sleep duration and PSQI-habitual sleep efficiency (frequent nightmares vs. non-frequent nightmares: PSQI-sleep duration, 1.08 ± 0.97 vs. 0.74 ± 0.85, P < 0.001; PSQI-habitual sleep efficiency, 1.08 ± 1.10 vs. 0.62 ± 0.88, P < 0.001). Reduced sleep duration and reduced sleep efficiency were independently associated with frequent nightmares after adjustment for age, sex, poor mental health, and regular sleeping medication use (reduced sleep duration: OR = 1.96, 95% CI = 1.07–3.58, P = 0.029; reduced sleep efficiency: OR = 2.17, 95% CI = 1.09–4.32, P = 0.027). Subjects with both reduced sleep duration and sleep efficiency were also associated with frequent nightmares (OR = 2.70, 95% CI = 1.57–4.65, P < 0.001).

Conclusion

The present study found that sleep duration and sleep efficiency were both independently associated with frequent nightmares among frontline medical workers in Wuhan during the COVID-19 pandemic. We should pay attention to nightmares and even the ensuing PTSD symptoms among subjects with reduced sleep duration or sleep efficiency facing potential traumatic exposure.