Nearly seven in 100 Icelandic women report symptoms of trauma-related nightmares and sleep disturbances, highlighting how violence, repeated stress, and recent life events can leave a lasting mark on sleep and mental health.
Study: Trauma-related sleep disorders in women in a national study. Image credit: Frame Stock Footage / Shutterstock
In a recent study published in the journal communication medicineResearchers assessed the prevalence of trauma-related sleep disorders (TASD) in Icelandic-speaking women aged 18 to 69 years in Iceland.
Trauma-related sleep disorder (TSD) has been proposed to be an underdiagnosed sleep phenotype that occurs after experiencing a traumatic event. It is characterized by hyperarousal during sleep, disruptive nocturnal behaviors (DNB), and trauma-related nightmares (TRN). One of the core symptoms of post-traumatic stress disorder (PTSD) is sleep disturbance, which often lingers long after other symptoms have subsided.
TSD remains a clinical phenotype under investigation and can co-occur with PTSD or persist independently. TSD research has primarily focused on male populations in high-stress occupations, including military service. Therefore, information regarding the prevalence of this infection in other populations, such as non-military populations and female populations, is limited.
About research
In this study, researchers investigated the prevalence and associated factors of TASD in Icelandic women. These included Icelandic-speaking female residents aged 18 to 69 who participated in a stress and genetic analysis cohort study. People with cognitive brain disorders or missing data on TASD or life stressors were excluded. Participants completed an online questionnaire regarding their health status and trauma history.
Exposure to life stressors was assessed using the Life Event Checklist Revised for DSM-5 (LEC-5). Past month TASD symptom criteria were assessed using items from the PTSD Checklist for DSM-5 (PCL-5) and the Pittsburgh Sleep Quality Index for PTSD (PSQI) Appendix (PSQI-A). TASD was defined as the presence of TRN and DNB, exposure to significant life stressors, and PSQI-A score >3. Common sleep problems occurring within the past month were assessed using the PSQI.
Probable PTSD within the past month was assessed using the PCL-5. Anxiety and depressive symptoms were assessed using the Generalized Anxiety Disorder (GAD-7) scale and the Patient Health Questionnaire (PHQ-9), respectively. Suicidal ideation, suicide attempts, and self-harm in the past 5 years were assessed using the World Mental Health (WMH) Composite International Diagnostic Interview (CIDI). Sociodemographic data were also collected from participants.
TASD prevalence was estimated, and Poisson regression models calculated prevalence rates for associations between TASD and psychiatric, sociodemographic, and trauma-related factors. The model was adjusted for education, age, employment status, personal income, relationship status, temporal proximity to the worst life stressor, and number of life stressors. Poisson generalized estimating equations (GEE) models were used to assess age-related effect changes.
Survey results
The study included 27,938 participants, with an average age of 43.7 years. The prevalence of TASD in the sample was 6.9%. Most were employed (81%) and in a relationship or married (76%). Approximately 39% of participants experienced two or three life stressors. Among PSQI-A symptoms, DNB was the least frequent, and hot flashes and generalized nervousness were the most common. TASD prevalence was highest in the 18-29 age group.
Having primary or secondary education, smoking, unemployment, binge drinking, or being single/widowed were associated with higher TASD prevalence. Of note, TASD prevalence increased with the number of life stressors experienced. Repeated exposure to life’s worst stressors was found to increase TASD prevalence by 48%.
Participants who had recently been exposed to the worst life stressors (within the past year) had the highest TASD prevalence, whereas participants who had been exposed more than 20 years ago had the lowest. Some life stressors, such as physical and sexual violence, confinement, sudden violent death, sudden accidental death, life-threatening injury or illness, and stillbirth, were strongly associated with TASD. Combat/combat zone exposure also showed a strong association, but this estimate is based on a very small subgroup and should be interpreted with caution.
Researchers also looked at overlap with mental health symptoms. Furthermore, TASD was strongly associated with the likelihood of PTSD. 74% of participants with TASD also showed possible PTSD. The prevalence of TASD was increased in participants with symptoms of depression, general sleep problems, or anxiety. Self-harm and suicidal ideation within the past 5 years were associated with TASD. A small subset of participants had TASD without the possibility of PTSD or general sleep disorders, supporting that trauma-related sleep disturbances can occur outside of broader PTSD symptoms.
conclusion
The prevalence of TASD among women aged 18 to 69 years in Iceland was 6.9%. Sexual and physical violence, stillbirth, and exposure to combat or combat zones were associated with significantly increased prevalence, but combat-related estimates were imprecise. Temporal proximity and repeated exposure to life’s worst stressors were associated with increased TASD prevalence.
Current age and recent age of trauma appear to be more related than age when the worst life stressor first occurred. TASD was strongly associated with PTSD, anxiety, and depressive symptoms. Because this study was cross-sectional and based on self-reported trauma and sleep symptoms, polysomnography cannot be used to establish causality or confirm TSD.
Overall, the findings highlight the potential value of early detection of TASD and sleep-focused interventions.
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