Polysomnographic Sleep and Attentional Deficits in Traumatized North Korean Refugees

Improving Sleep Health Among Refugees: A Systematic Review

Purpose of Review

Sleep disorders among refugees are common yet understudied. Interventions are difficult in resource-limited settings where most of these populations live. A systematic review of sleep disorders in refugee populations is warranted to identify prevalence, comorbidities, and the limitations of the current state of sleep health among refugees.

Recent Findings

Sleep disturbances, particularly insomnia and nightmares, occur with a higher prevalence among refugees. Diseases associated with insomnia in this population included fibromyalgia, posttraumatic stress disorder, depression, and anxiety. Risk factors include trauma, migration, lower socioeconomic status, lower educational level, and settlement in areas with a high influx of new residents or proximity to conflict. Only a few partially successful therapies were identified.

Summary

This review identifies the high prevalence of the disturbed sleep in this population and its risk factors. It proposes ways of increasing awareness of it in this vulnerable population as a first step toward remediation.

Sleep impairments in refugees diagnosed with post-traumatic stress disorder: a polysomnographic and self-report study

Background: Post-traumatic stress disorder (PTSD) is the clinical manifestation of traumatic events and is associated with sleep disturbances. Sleep disturbances, if left untreated, may perpetuate or even worsen symptoms of PTSD. Previous studies of other PTSD populations show a higher incidence of sleep impairments and sleep disorders compared to healthy controls (HCs); however, this has never been investigated in trauma-affected refugees diagnosed with PTSD.Objectives: To examine subjective sleep quality, measure sleep architecture, and identify latent sleep disorders in refugees diagnosed with PTSD compared to HCs.Method: This comparative study included 20 trauma-affected refugees diagnosed with PTSD and 20 HC matched on age, sex, and body mass index. All participants completed self-report questionnaires assessing sleep quality, insomnia severity, and disturbing nocturnal behaviour, and all took part in a one-night polysomnography (PSG) assessment.Results: Patients reported significantly poorer subjective sleep quality, sleep latency, sleep duration, and sleep efficiency compared to HCs. Subjective reports on hours spent in bed were not significantly different between patients and HCs. Patients reported significantly higher nightmare frequency and severity compared to HCs. PSG measures showed that patients had significantly reduced sleep efficiency, more awakenings, and longer REM sleep latency, and spent more time awake, whereas there was no significant differences regarding total time in bed, total sleep time, or sleep latency. The prevalence of sleep disorders was equal between groups.Conclusions: The study identified significant impairments in several sleep domains, with a preponderance of disturbed regulation of sleep resulting in awakenings. These results indicate a need for more focus on hyperarousal and nightmares as key elements of disturbed sleep in PTSD. Furthermore, the study identified a discrepancy between subjective and objective measures concerning total sleep time, raising questions regarding the causes of 'sleep state misperception'.Trial registration: ClinicalTrials.gov identifier: NCT03535636..Trial registration: Sleep Impairments in Refugees Diagnosed with PTSD (PSG-PTSD). URL: https://clinicaltrials.gov/ct2/show/NCT03535636. ClinicalTrials.gov NCT03535636. Date of registration: 24/05/2018.

Gray Matter Volume of Thalamic Nuclei in Traumatized North Korean Refugees

The current study investigated differences in the regional gray matter (GM) volume of specific thalamic nuclei between North Korean (NK) refugees and South Korean (SK) residents. It also investigated associations between thalamic GM volume changes and psychological symptoms. Psychological evaluations and magnetic resonance imaging were conducted on 50 traumatized NK refugees and 55 non-traumatized SK residents. The regional GM volume ratios in the bilateral thalami were calculated for all participants using voxel-based morphometry. NK refugees showed greater GM volume ratios in the right medial-posterior nuclei and left medial nuclei compared with SK residents. NK refugees also exhibited more depressive symptoms than SK residents. However, increased GM volume ratios in both right medial-posterior nuclei and left medial nuclei were correlated with fewer depressive symptoms in NK refugees, but not in SK residents. The findings indicate that traumatized NK refugees had increased GM volumes in the right medial-posterior nuclei and left medial nuclei, which were associated with fewer depressive symptoms. The enlarged specific thalamic nuclei presented among refugees in the current study might be associated with a neurobiological compensatory mechanism that prevents the development or progression of depression in refugees after repetitive traumatic experiences.