Association between defense mechanisms and psychiatric symptoms in North Korean Refugees.

OBJECTIVE: Defense mechanism may contribute to psychiatric symptoms. Refugees are vulnerable to various psychiatric symptoms, such as depression, anxiety, somatization, and those associated with post-traumatic stress disorder (PTSD), due to their traumatic or stressful experiences. We aimed to investigate the mediating role of each defense mechanism in the occurrence of specific psychiatric symptoms in North Korean refugees. METHOD: Among 213 North Korean refugees initially recruited, 201 completed the following questionnaires: the Defense Style Questionnaire, the Center for Epidemiological Studies-Depression Scale (CES-D), the State-Trait Anxiety Inventory-State (STAI-S), the somatization subscale of Symptom Check-List-90-Revised (SCL-90-R), and the Impact of Event Scale-Revised (IES-R). Stepwise regression analysis was performed to determine the defense mechanisms more predominantly associated with specific psychiatric symptoms after controlling for age, sex, number of traumatic experiences, and other psychiatric symptoms (depressive symptoms and/or anxiety). RESULTS: Higher levels of depression were independently predicted by greater use of resignation. More use of acting out and less use of humor and sublimation independently predicted higher levels of anxiety. Somatization was independently predicted by more use of inhibition. PTSD symptoms were independently predicted by more use of undoing and isolation. CONCLUSIONS: Specific psychiatric symptoms were associated with specific defense mechanisms in North Korean refugees. Our findings suggest that the manifest psychiatric symptoms of refugees may be mediated by their dominant defense mechanism.

The relationship between poor performance on attention tasks and increased suicidal ideation in adolescents.

Our goal was to examine the relationship between attention and suicidal ideation in a school-based adolescent population. This cross-sectional study involved 2,462 students from eight high schools in South Korea (1,021 males and 1,441 females, mean age 17.3 ± 0.6 years). The participants completed the Beck Scale for Suicide Ideation (SSI) and the Beck Depression Inventory (BDI) and took part in computerized attention tasks. Participants with high SSI scores (16 or higher) exhibited a higher mean number of omission errors (OEs) and commission errors (CEs) on the visual sustained attention tasks than did participants with low SSI scores (p < 0.001 and p < 0.001, respectively). On the divided attention tasks, the high SSI group exhibited a higher mean number of CEs than the low SSI group did (p < 0.001). In a general linear model adjusting for age, gender, and high BDI (10 or higher), membership in the high OE group in the visual sustained attention tasks was associated with high SSI scores (p = 0.015). Belonging to the high OE or CE group in the divided attention tasks were associated with high SSI scores (p = 0.024 and p = 0.035, respectively). For both the visual sustained and divided attention tasks, interactions between gender and high OE rates were significant (p ≤ 0.001 and p = 0.013, respectively). In the post hoc analysis, membership in the high OE group was associated with high SSI scores for girls. In a multiple linear regression analysis including all participants and controlling for age, gender, and BDI scores, higher numbers of OEs and CEs on the visual sustained attention tasks predicted higher SSI scores (p < 0.001 and p = 0.019, respectively). On the divided attention task, the number of CEs was positively correlated with the SSI score (p = 0.031). The findings of this study indicate an association between attention deficits and increased suicidal ideation in adolescents after controlling for depressed mood. The current results suggest a direct link between attention deficits and increased suicidality independent of depressive symptoms in adolescents.

The effect of cognitive behavioral therapy for insomnia in schizophrenia patients with sleep Disturbance: A non-randomized, assessor-blind trial.

This non-randomized, assessor blind study evaluated the effects of cognitive behavioral therapy for insomnia (CBT-I) delivered in a group format on insomnia symptoms as well as psychotic, depressive, and anxiety symptoms in schizophrenia patients (n = 63) recruited from residential or rehabilitative facilities in Seoul, South Korea. Thirty-one patients received four sessions of CBT-I in groups of 2-9 patients in addition to usual care, while the control group (n = 32) received no additional intervention. The Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI), Psychotic Symptoms Rating Scale (PSYRATS), Anxiety Sensitivity Index (ASI), and Beck Depression Inventory (BDI) were administered at baseline, week 4, and week 8. Both groups showed significant time-group interactions on the ISI and PSQI. Post hoc testing showed that, compared to the control group, the CBT-I group showed significant reductions in ISI and PSQI at both week 4 and week 8. For the PSYRATS, ASI, and BDI scores, the CBT-I and control groups showed significant time-group interactions, but post hoc testing revealed no significant group differences at either week 4 or week 8. Therefore, CBT-I was effective for reducing insomnia symptoms in patients with schizophrenia and the effect lasted for 4 weeks after the intervention.

Changes in subcortical resting-state functional connectivity in patients with psychophysiological insomnia after cognitive-behavioral therapy: Changes in resting-state FC after CBT for insomnia patients.

STUDY OBJECTIVES: To examine the resting-state functional connectivity (FC) between subcortical regions in relation to whole-brain activity in patients with psychophysiological insomnia (PI) and changes following cognitive-behavioral therapy for insomnia (CBTi). METHODS: The FC between subcortical seed regions (caudate, putamen, pallidum, amygdala, thalamus, and hippocampus) and whole-brain voxels were compared between the PI group (n = 13, mean age: 51.0 ± 10.2 years) and good sleepers (GS, n = 18, mean age: 42.7 ± 12.3 years). Also, in the PI group, FC was compared before and after 5 weeks of CBTi. RESULTS: Compared to the GS group, the PI group exhibited stronger FC between the thalamus and prefrontal cortex and between the pallidum and precuneus but weaker FC between the pallidum and angular gyrus, the caudate and orbitofrontal cortex, and the hippocampus and fusiform gyrus. After CBTi, the PI group exhibited decreased FC between the thalamus and parietal cortex, the putamen and motor cortices, and the amygdala and lingual gyrus, but increased FC between the caudate and supramarginal gyrus, the pallidum and orbitofrontal cortex, and the hippocampus and frontal/parietal gyri. CONCLUSIONS: The present findings demonstrate different FC in PI patients compared to GS and provide insight into the neurobiological rationale for CBTi.

Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults.

OBJECTIVE: The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. METHODS: We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. RESULTS: The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch. CONCLUSION: Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.

Differential Effects of Obesity on Obstructive Sleep Apnea Syndrome according to Age.

OBJECTIVE: To evaluate the effect of obesity on obstructive sleep apnea syndrome (OSAS) by age in relation to anthropometric measurements. METHODS: The medical records of 1,110 participants diagnosed with OSAS were analyzed according to age. All participants underwent nocturnal polysomnography and had their body mass index, waist circumference, neck circumference (NC), and waist-to-hip ratio measured. RESULTS: According to the multiple linear regression analysis model for the natural logarithm of the apnea-hypopnea index treating all four anthropometric measurements and gender as covariates, the final stepwise model accounted for an increasing percentage of the variability in the severity of OSAS as a function of age: 7.0, 9.1, 14.5, and 25.6% for those aged <30, 30-39, 40-49, and 50-59 yrs, respectively. It accounted for a decreased percentage among those 60-69 (20.3%) and 70 yrs or older (3.9%). The correlation between NC and the severity of OSAS linearly increased as a function of age for those aged 30-59 yrs, peaked among those in their 60s, and dramatically decreased thereafter. CONCLUSION: Middle-aged patients with OSAS were more likely to be obese, as measured by anthropometric measurements, than were younger or older OSAS patients. In particular, the predictive value of NC was significantly lower for younger and older OSAS patients.

Sleep EEG Characteristics in Young and Elderly Patients with Obstructive Sleep Apnea Syndrome.

OBJECTIVE: In the present study, it was hypothesized that the sleep electroencephalogram (EEG) characteristics of young (<30 yrs) and elderly (>55 yrs) OSAS patients would differ. METHODS: We analyzed 76 sleep EEG recordings from OSAS patients (young group: n=40, mean age: 24.3±4.9 yrs; elderly group: n=36, mean age: 59.1±4.9 yrs), which were obtained during nocturnal polysomnography. The recordings were assessed via spectral analysis in the delta (0.5-4.5 Hz), theta (4.5-8 Hz), alpha (8-12 Hz), beta (12-32 Hz), slow sigma (11-13 Hz), and fast sigma (13-17 Hz) frequency bands. RESULTS: Apnea Hypopnea Index (AHI) and sleep efficiency (%) did not differ significantly between the two groups (19.8±14.4 vs. 25.9±16.0, p=0.085; 84.4±12.6 vs. 80.9±11.0, p=0.198, respectively). After adjusting for gender, the slow/fast sigma ratio was not significantly correlated with AHI in the elderly group (r=-0.047, p=0.790) but AHI was inversely correlated with the slow/fast sigma ratio in the young group (r=-0.423, p=0.007). A multiple linear regression analysis revealed that a higher AHI was related with a lower slow/fast sigma ratio in the young group (ß=-0.392, p=0.028) but not the elderly. CONCLUSION: In the present study, sleep EEG activity differed between young and elderly OSAS patients. The slow/fast sigma ratio was associated with OSAS severity only in young patients, suggesting that young OSAS patients may have a distinctive brain plasticity compared with elderly patients.

Insomnia in North Korean Refugees: Association with Depression and Post-Traumatic Stress Symptoms.

OBJECTIVE: We investigated the prevalence of insomnia and its clinical characteristics in North Korean refugees. METHODS: North Korean refugees living in South Korea (48 males, 129 females; mean age 38.22±12.24 years) and South Koreans (112 males, 203 females; mean age 39.48±10.32 years) completed the following questionnaires: the Self-reported Questionnaire on Insomnia, Center for Epidemiological Studies-Depression Scale (CES-D), Trauma Exposure Check List for North Korean Refugees, and the Impact of Event Scale-Revised (IES-R). RESULTS: North Korean refugees had insomnia more often than South Koreans did (38.42% vs. 8.89%). Depression combined with insomnia was also more prevalent in North Korean refugees (28.25% vs. 3.17%). Compared with South Koreans with insomnia, North Korean refugees with insomnia showed higher CES-D scores. The North Korean refugees with insomnia had experienced a larger number of traumatic events, and had higher CES-D and IES-R scores compared to North Korean refugees without insomnia. Insomnia in North Korean refugees was also associated with the presence of significant depressive and post-traumatic stress disorder (PTSD) symptoms. CONCLUSION: Insomnia was common in North Korean refugees and was closely associated with depressive and PTSD symptoms. Our study suggests that complaints of insomnia may indicate more severe psychopathology, especially in refugees.

Nocturnal awakening and sleep efficiency estimation using unobtrusively measured ballistocardiogram.

Fragmented sleep due to frequent awakenings represents a major cause of impaired daytime performance and adverse health outcomes. Currently, the gold standard for studying and assessing sleep fragmentation is polysomnography (PSG). Here, we propose an alternative method for real-time detection of nocturnal awakening via ballistocardiography using an unobtrusive polyvinylidene fluoride (PVDF) film sensor on a bed mattress. From ballistocardiogram, heart rate and body movement information were extracted to develop an algorithm for classifying sleeping and awakening epochs. In total, ten normal subjects (mean age 38.7 ± 14.6 years) and ten patients with obstructive sleep apnea (OSA) (mean age 44.2 ± 16.5 years) of varying symptom severity participated in this study. Our study detected awakening epochs with an average sensitivity of 85.3% and 85.2%, specificity of 98.4% and 97.7%, accuracy of 97.4% and 96.5%, and Cohen's kappa coefficient of 0.83 and 0.81 for normal subjects and OSA patients, respectively. Also, sleep efficiency was estimated using detected awakening epochs and then compared with PSG results. Mean absolute errors in sleep efficiency were 1.08% and 1.44% for normal subjects and OSA patients, respectively. The results presented here indicate that our suggested method could be reliably applied to real-time nocturnal awakening detection and sleep efficiency estimation. Furthermore, our method may ultimately be an effective tool for long-term, home monitoring of sleep-wake behavior.

Obstructive sleep apnea syndrome is associated with higher diastolic blood pressure in men but not in women.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) and poor sleep quality both increase blood pressure (BP). This study aimed to find the sex effects and the role of poor sleep quality on systolic BP (SBP) and diastolic BP (DBP) in OSAS patients. METHODS: Polysomnographic findings, morning BP values, and clinical data of 460 subjects (348 men; 112 women) diagnosed with OSAS were analyzed. Analyses were performed separately in each sex to examine the association of the apnea-hypopnea index (AHI) with BP, SBP, DBP, and sleep quality. RESULTS: In male subjects, AHI predicted the high BP and high DBP groups but not the high SBP group. In female subjects, AHI did not predict any of the high BP, DBP, or SBP groups. Poor sleep quality, in the absence of AHI effect, weakly correlated with BP in both sexes, but the association between poor sleep quality and high AHI was stronger in male subjects than in females. CONCLUSIONS: In male subjects only, OSAS was associated with DBP but not SBP. The significant association between OSAS and DBP may be responsible for the BP elevations in OSAS. It could be speculated that the stronger association between poor sleep quality and OSAS in male subjects compared with females may have partly contributed to the sex effect on BP.

Effect of quetiapine XR on depressive symptoms and sleep quality compared with lithium in patients with bipolar depression.

BACKGROUND: Bipolar depression is one of the most serious psychiatric conditions. In addition, sleep disturbance in bipolar disorder is common, and therapeutic agents restoring sleep disturbances in bipolar disorder patients will be clinically beneficial. In the current study, we compared the effect of quetiapine XR with lithium on depressive symptoms and sleep in bipolar depression patients during 8 weeks of trial. METHODS: An open-label, randomized comparison of sleep-activity and depressive symptoms between 8-week quetiapine XR monotherapy and lithium monotherapy for bipolar depression was conducted. Each assessment consisted of HDRS-17, Clinical Global Impression-severity (CGI-S), and self-reported Pittsburgh Sleep Quality Index (PSQI). Actigraphy-measured sleep parameters were assessed. RESULTS: A total of 42 patients (35.7±10.9 years; gender: male 15, female 27) with bipolar depression were screened out. Out of 42 patients, six patients were excluded before randomization. After randomization, seven patients were withdrawn. Twenty-nine patients with more than two visits after randomization (lithium group: 17, quetiapine XR group: 12, mean age: 36.1±10.4, gender: male 13, female 16) were included in the final analysis. In both groups, Hamilton Depression Rating Scale (HDRS) scores were significantly decreased at weeks 1, 2, 4, 6, and 8 compared with baseline. Remission rate (HDRS≤7) in the quetiapine XR was significantly higher than that of the lithium group. In the quetiapine XR group, PSQI scores at weeks 1, 2, 4, 6, and 8 was significantly decreased compared with baseline. Sleep efficiency at weeks 6 and 8 was significantly increased. WASO at week 8 was significantly decreased. LIMITATIONS: First, the present study was conducted with the relatively small number of study subjects. Second, bias could have affected the study results due to its open-label design. Third, study subjects were made up of high proportion of bipolar II disorder patients. CONCLUSIONS: Quetiapine XR monotherapy was more effective in treating bipolar depression than lithium. In particular, quetiapine XR treatment improved both subjective and objective sleep quality in patients with bipolar depression. However, relationship between favorable sleep quality and depressive symptom improvement were limited.

Unconstrained sleep apnea monitoring using polyvinylidene fluoride film-based sensor.

We established and tested an unconstrained sleep apnea monitoring method using a polyvinylidene (PVDF) film-based sensor for continuous and accurate monitoring of apneic events occurred during sleep. Twenty-six sleep apnea patients and six normal subjects participated in this study. Subjects' respiratory signals were measured using the PVDF-based sensor during polysomnography. The PVDF sensor comprised a 4 × 1 array, and a thin silicon pad was placed over the sensor to prevent damage. Total thickness of the merged system was approximately 1.1 mm which was thin enough to prevent the subject from being consciously aware of its presence. It was designed to be placed under subjects' backs and installed between a bed cover and mattress. The proposed method was based on the standard deviation of the PVDF signals, and it was applied to a test set for detecting apneic events. The method's performance was assessed by comparing the results with a sleep physician's manual scoring. The correlation coefficient for the apnea-hypopnea index (AHI) values between the methods was 0.94 (p < 0.001). The areas under the receiver operating curves at three AHI threshold levels (>5, >15, and >20) for sleep apnea diagnosis were 0.98, 0.99, and 0.98, respectively. For min-by-min apnea detection, the method classified sleep apnea with an average sensitivity of 72.9%, specificity of 90.6%, accuracy of 85.5%, and kappa statistic of 0.60. The developed system and method can be applied to sleep apnea detection in home or ambulatory monitoring.