Association Between Subjective-Objective Discrepancy of Sleeping Time and Health-Related Quality of Life: A Community-Based Polysomnographic Study.

OBJECTIVE: This study aimed to investigate the existence of a difference in quality of life (QOL) between individuals with and without significant subjective-objective discrepancy (SOD) in total sleep time (TST). METHODS: From the Sleep Heart Health Study 2, 2540 individuals who had completed polysomnography, a morning sleep survey, and the 36-item Short-Form Health Survey (SF-36) were included in the analyses. The participants were classified as normoestimators (estimation of TST <±60 minutes), underestimators (underestimation of TST ≥60 minutes), or overestimators (overestimation of TST ≥60 minutes). The standardized SF-36 QOL scores were compared among the three groups. An adjusted partial correlation analysis was conducted between SOD and QOL. RESULTS: Of the 2540 participants, 1617 (63.7%), 433 (17.0%), and 490 (19.3%) were assigned to the normoestimator, underestimator, and overestimator groups, respectively. The bodily pain and social functioning components of the SF-36 score were significantly lower in the underestimators than in the normoestimators, whereas the physical functioning component was significantly lower in the overestimators than in the normoestimators. The absolute value of SOD in the TST showed a significant negative correlation with the physical and mental components of the SF-36. CONCLUSIONS: QOL was significantly better in the normoestimator than in the other groups and linearly correlated with the absolute value of SOD. This study suggests that a high prevalence of positive and negative sleep misperception in a community population can be a potential factor associated with poor QOL and potential comorbidities.

Thalamocortical functional connectivity in patients with insomnia using resting-state fMRI.

BACKGROUND: Insomnia is a common disorder that affects a vast number of patients; the hyperarousal theory of insomnia postulates that patients with insomnia are physiologically activated not only at nighttime but also during the daytime. We aimed to investigate the differences in the resting-state functional connectivity (RSFC) of the thalamus with cortical areas between patients with insomnia disorder and healthy controls. METHODS: All participants completed clinical questionnaires and underwent portable polysomnography and resting-state fMRI. RESULTS: Patients in the insomnia group (n = 50) showed increased RSFC between the thalamus and right medial superior frontal area, bilateral middle temporal areas, left rectus and right parahippocampal areas compared with controls (n = 42) after controlling for age, sex and education level. Among the pairs that showed increased connectivity, several functional connections were negatively correlated with sleep efficiency, measured by polysomnography.Limitations: We used a small sample size. CONCLUSION: We consider these results on increased thalamocortical hyperactivity in brain areas related to sensory functions as providing evidence for the hyperarousal theory of insomnia.

Neuroimaging Biomarkers for Predicting Treatment Response and Recurrence of Major Depressive Disorder.

The acute treatment duration for major depressive disorder (MDD) is 8 weeks or more. Treatment of patients with MDD without predictors of treatment response and future recurrence presents challenges and clinical problems to patients and physicians. Recently, many neuroimaging studies have been published on biomarkers for treatment response and recurrence of MDD using various methods such as brain volumetric magnetic resonance imaging (MRI), functional MRI (resting-state and affective tasks), diffusion tensor imaging, magnetic resonance spectroscopy, near-infrared spectroscopy, and molecular imaging (i.e., positron emission tomography and single photon emission computed tomography). The results have been inconsistent, and we hypothesize that this could be due to small sample size; different study design, including eligibility criteria; and differences in the imaging and analysis techniques. In the future, we suggest a more sophisticated research design, larger sample size, and a more comprehensive integration including genetics to establish biomarkers for the prediction of treatment response and recurrence of MDD.

Cognitive Behavioral Therapy for Insomnia in the Digital Age.

Cognitive behavioral therapy for insomnia (CBT-I) is the treatment of choice for insomnia; however, it is not widely used due to a lack of experienced therapists and its relatively high clinical cost. Recently, Internet and mobile CBT-I have been developed to replace face-to-face CBT-I, and research on this topic has been increasing. In addition, attempts have been made to use wearable devices for sleep-wake estimation. Studies on digital CBT-I thus far have shown favorable treatment effects in general, but the problem of a high dropout rate has not been sufficiently improved. In addition, more sophisticated technology is needed to develop fully automated digital CBT-I. As part of efforts to maximize the treatment effectiveness of future insomnia patients, research and development of mobile and Internet CBT-I and improvement of sleep tracker accuracy and validation studies are needed.

Decreased regional brain activity in response to sleep-related sounds after cognitive behavioral therapy for psychophysiological insomnia.

AIM: Patients with psychophysiological insomnia (PI) experience hyperarousal, especially as a reaction to sound stimuli. In the current study, we explored brain activity changes in response to sleep-related sounds (SS) in patients with insomnia after cognitive behavioral therapy for insomnia (CBT-I). METHODS: In 14 drug-free PI patients, regional brain activity in response to SS, and to white noise sound (NS) as neutral stimuli, was investigated before and after individual CBT-I using functional magnetic resonance imaging. Blood oxygen level-dependent (BOLD) signals to SS and NS were compared before and after CBT-I. In addition, the association between clinical improvement after CBT-I and changes in brain activity in response to SS and NS was analyzed. RESULTS: Compared with baseline, regional brain activity in response to SS after CBT-I decreased in the left middle temporal and left middle occipital gyrus. In regression analysis, a reduction in the Dysfunctional Beliefs and Attitudes about Sleep (DBAS) Scale score after CBT-I was associated with decrease in brain activity in response to SS in both thalami. However, brain activity in response to NS showed no BOLD signal changes and no association with DBAS change. CONCLUSION: Cortical hyperactivity, which may cause hyperarousal in PI, was found to decrease after CBT-I. CBT-I targeting changes in beliefs and attitudes about sleep may induce its therapeutic effects by reducing thalamic brain activity in response to sleep-related stimuli.

Comparison of Psychiatric Symptoms in Patients With Obstructive Sleep Apnea, Simple Snoring, and Normal Controls.

OBJECTIVE: Patients with sleep-related breathing disorders are known to have more severe psychiatric symptoms than good sleepers. The aim of this study was to compare the psychiatric symptoms of participants with obstructive sleep apnea (OSA), those with simple snoring (SS), and normal controls (NC). METHODS: A total of 386 participants (260 with OSA, 75 with SS, and 51 NC) completed self-report questionnaires including the Symptoms Checklist 90-Revised and underwent nocturnal polysomnography. The scores of nine primary symptom dimensions and three global distress indices of the Symptoms Checklist 90-Revised were compared among the three groups, adjusting for age, sex, and body mass index. RESULTS: Participants with suspected OSA (OSA + SS) reported more severe psychiatric symptoms than the NC group. Compared with the participants with OSA, those with SS manifested more severe obsessive-compulsive (1.4 (1.0) versus 1.1 (0.7), p = .008) and depressive (1.2 (1.2) versus 0.8 (0.8), p = .031) symptoms and higher Global Severity Index (1.0 (0.9) versus 0.7 (0.6), p = .039) and Positive Symptom Distress Index (2.0 (0.8) versus 1.7 (0.6), p = .009). Only higher Pittsburgh Sleep Quality Index values predicted higher Global Severity Index (B = 0.11, p = .041) and Positive Symptom Distress Index (B = 0.46, p = .007) in suspected OSA participants. CONCLUSIONS: This study found that individuals with suspected OSA experienced more severe psychiatric symptoms than NCs and that psychiatric symptoms were more severe in the SS group than in the OSA group. The psychiatric symptoms of suspected OSA patients were associated with subjective sleep quality rather than with the apnea-hypopnea index.

Low white-matter integrity between the left thalamus and inferior frontal gyrus in patients with insomnia disorder

Background: Previous studies have reported functional and structural abnormalities in the thalamus and the pars triangularis of the inferior frontal gyrus in patients with insomnia disorder. However, no studies have been conducted on the white-matter tracts between these 2 brain regions. We aimed to compare the white-matter integrity and structure of the left thalamus­pars triangularis tracts between patients with insomnia and controls, and to characterize the relationship between white-matter integrity and clinical features in patients with insomnia. Methods: In total, 22 participants with insomnia disorder and 27 controls underwent overnight polysomnography and brain magnetic resonance imaging, and then completed self-report clinical questionnaires and neurocognitive tests for spatial planning. Structural and diffusion measures such as fractional anisotropy, axial diffusivity, radial diffusivity and trace were analyzed in group comparison and correlation analyses. Results: The insomnia group showed significantly lower fractional anisotropy (F = 8.647, p = 0.02) and axial diffusivity (F = 5.895, p = 0.038) in the left thalamus­pars triangularis tracts than controls. In patients with insomnia, fractional anisotropy in the tracts was correlated with the results of the Stockings of Cambridge test (r = 0.451, p = 0.034), and radial diffusivity was correlated with Epworth Sleepiness Scale score (r = 0.437, p = 0.042). Limitations: Limitations included analyses of limited brain regions and the cross-sectional design. Conclusion: The insomnia group showed decreased integrity in the left thalamus­pars triangularis tracts, and integrity was correlated with cognition and daytime sleepiness. These results may imply that insomnia is characterized by disintegration of the white-matter tract between the left thalamus and inferior frontal gyrus.

Suicide Methods According to Age and Sex: An Analysis of Data of 239,565 Suicide Victims in the Republic of Korea From 1991 to 2015.

Because suicide is irreversible, prevention is paramount. For the optimal strategy to reduce lethal means, we sought to investigate age- and sex-associated variations in suicide methods. Data on annual causes of death from 1991 to 2015 in the Republic of Korea were used. Major sociodemographic correlates of the five suicide methods were analyzed by multiple multinominal logistic regression analysis. Among a total of 239,565 suicides from 1991 to 2015, hanging was most common. Gas poisoning sharply increased from 2007 to 2015. The gap between hanging and the second most common method of suicide has increased from 659 in 2004 to 4,433 in 2015. Charcoal burning was most commonly used by males younger than 45 years of age, whereas pesticide was commonly used by both sexes ages 55 years and older. Our results suggest that age- and sex-specific suicide prevention strategies are needed, particularly for gas and pesticide poisoning.

fMRI brain activation in patients with insomnia disorder during a working memory task.

PURPOSE: This study used functional magnetic resonance imaging (fMRI) to investigate differences in the functional brain activation of patients with insomnia disorder (n = 21, mean age = 36.6) and of good sleepers (n = 26, mean age = 33.2) without other comorbidities or structural brain abnormalities during a working memory task. METHODS: All participants completed a clinical questionnaire, were subjected to portable polysomnography (PSG), and performed the working memory task during an fMRI scan. The subjects who were suspected of major sleep disorder and comorbid psychiatric disorders except insomnia disorder were excluded. To compare the brain activation on working memory from the insomnia group with those from the good-sleeper group, a two-sample t test was performed. Statistical significance was determined using 3DClustSim with the updated algorithm to obtain a reasonable cluster size and p value for each analysis. RESULTS: We observed higher levels of brain activation in the right lateral inferior frontal cortex and the right superior temporal pole in the insomnia group compared to good sleepers (cluster-based multiple comparison correction, p < 0.001, k = 34 @ α = 0.01). CONCLUSION: Thus, patients with insomnia disorder showed increased brain activation during working memory relative to good sleepers, and this may be indicative of compensatory brain activation to maintain cognitive performance in patients with insomnia disorder without other comorbidities.

Decreased serum magnesium levels in depression: a systematic review and meta-analysis.

BACKGROUND: Magnesium (Mg2+), an endogenous N-methyl-D-aspartate receptor antagonist, has received increased attention recently because of its role in the pathophysiology of and treatment response in depression. However, whether Mg2+ level is decreased in depression is not firmly established. We aimed to conduct a systematic review and meta-analysis to help making consensus for the association between Mg2+ levels and depression. METHODS: A systematic search was conducted in the electronic database resources PubMed and Embase. After a careful selection of relevant studies, a meta-analysis using the random effects model was conducted in each measuring source, such as serum, plasma, and cerebrospinal fluid (CSF). RESULTS: A total of 18 studies were included in this study. Among 11 studies that measured Mg2+ in the serum, Mg2+ level was lower in patients with depression than in controls (weighted mean difference = -.088, 95% confidence interval = -.164 to -.012). In the sensitivity analysis by removing studies one by one, 2 out of the 11 studies obliterated such significant differences. There were no significant differences in the Mg2+ levels in the studies for plasma and CSF. CONCLUSIONS: Despite some evidence supporting an association between decreased Mg2+ levels and depression from studies with serum, the results of our meta-analysis urge to use caution when associating Mg2+ levels and depression. Future studies are needed to establish a consensus for the role of low Mg2+ levels in depression.

Comparison of the Effects of Quetiapine XR and Lithium Monotherapy on Actigraphy-Measured Circadian Parameters in Patients With Bipolar II Depression.

PURPOSE/BACKGROUND: The aim of this study was to evaluate the effects of quetiapine XR and lithium on actigraphy-measured circadian parameters in patients with bipolar II depression. METHODS/PROCEDURES: This was an 8-week, open-label, prospective, randomized comparative study. The assessments included the 17-item Hamilton Depression Rating Scale score and actigraphic measures concerning the previous 7 days, collected at each visit (weeks 0 [baseline], 1, 2, 4, 6, and 8); the actigraphic data were analyzed with a cosinor analysis. FINDINGS/RESULTS: Medication, time, and the interaction between medication and time were significantly associated with acrophase for the entire group (Ps = 0.003, 0.020, and 0.042, respectively). More specifically, acrophase was significantly delayed at weeks 1 and 6 (Ps = 0.004 and 0.039, respectively) in the quetiapine XR group. The F statistics significantly increased over time for the entire group (P < 0.001), and there was a significant increase in F statistics on weeks 4 and 6 in the quetiapine XR group (Ps = 0.016 and 0.020, respectively) and on weeks 4 and 8 in the lithium group (Ps = 0.001 and 0.016, respectively). In addition, scores on the 17-item Hamilton Depression Rating Scale were significantly associated with the F statistics during 8 weeks for the entire group (P = 0.008). IMPLICATIONS/CONCLUSIONS: Both quetiapine XR and lithium affected several circadian parameters, including peak activity time and robustness of circadian rhythm, but exerted different effects on acrophase in patients with bipolar II depression. In particular, clinical depressive symptoms were associated with robustness of circadian rhythm during the course of the 8-week treatment.

rs7968606 polymorphism of ANKS1B is associated with improvement in the PANSS general score of schizophrenia caused by amisulpride.

A recent genome-wide pharmacogenomics study showed that the rs7968606 single-nucleotide polymorphism (SNP) of the ankyrin repeat and sterile alpha motif domain-containing protein 1B (ANKS1B) gene approached the threshold of statistical significance. The aim of this study was to determine the association between the rs7968606 SNP of ANKS1B and the treatment response to amisulpride in schizophrenia patients. In total, 154 participants were enrolled from six university hospitals in Korea. All the subjects were interviewed before and after 6 weeks of amisulpride treatment with the aid of the positive and negative syndrome scale and the clinical global impression-severity scale. Genotyping for the rs7968606 SNP of ANKS1B was performed in 101 subjects. Both the decrease (t = -2.067, p = 0.041) and improvement rate (t = -1.990, p = 0.049) in the positive and negative syndrome scale general score differed significantly between T-allele carriers and noncarriers of this polymorphism after 6 weeks of amisulpride treatment. To the best of our knowledge, this is the first genetic association study of the relationship between the rs7968606 SNP of ANKS1B and the response of schizophrenia patients to treatment with amisulpride. Future larger-scale studies involving more SNPs of ANKS1B will improve the understanding of the pharmacogenetics underlying the treatment responses to amisulpride.

Formula for predicting OSA and the Apnea-Hypopnea Index in Koreans with suspected OSA using clinical, anthropometric, and cephalometric variables.

PURPOSE: This study developed formulas to predict obstructive sleep apnea (OSA) and the Apnea-Hypopnea Index (AHI) in Korean patients with suspected OSA using clinical, anthropometric, and cephalometric variables. METHODS: We evaluated relevant variables in 285 subjects with suspected OSA. These included demographic characteristics, sleep-related symptoms, medical history, clinical scales, anthropometric measurements including facial surface measurements, and cephalometric measurements. All participants underwent full-night laboratory polysomnography. The prediction formula for the probability of OSA was created by logistic regression analysis and confirmed by the bootstrap resampling technique. The formula for predicting the AHI was developed using multiple linear regression analysis. RESULTS: The probability of having OSA was as follows: p = 1 / (1 + exponential (exp)-f ), where f = -16.508 + 1.445 × loudness of snoring 4 + 0.485 × loudness of snoring 3 + 0.078 × waist circumference + 0.209 × subnasale-to-stomion distance + 0.183 × thickness of the uvula (UTH) supine + 0.041 × age. The AHI prediction formula was as follows: -112.606 + 3.516 × body mass index + 0.683 × mandibular plane-hyoid supine + 10.915 × loudness of snoring 4 + 6.933 × loudness of snoring 3 + 1.297 × UTH supine + 0.272 × age. CONCLUSION: This is the first study to establish formulas to predict OSA and the AHI in Koreans with suspected OSA using cephalometric and other variables. These results will contribute to prioritizing the order in which patients with suspected OSA are referred for polysomnography.

The quality of life of suspected obstructive sleep apnea patients is related to their subjective sleep quality rather than the apnea-hypopnea index.

PURPOSE: The relationship between the severity of the apnea-hypopnea index (AHI) and the quality of life (QOL) in patients with obstructive sleep apnea (OSA) has been inconsistent in previous studies. This study aimed to identify the core factor associated with the QOL of suspected OSA patients and to compare the QOL of subjects with OSA and simple snoring (SS). METHODS: Two hundred eighty-five subjects who were clinically suspected to have OSA underwent nocturnal polysomnography (PSG) and completed self-report questionnaires including the World Health Organization Quality of Life Short Form (WHOQOL-BREF) and the Pittsburgh Sleep Quality Index (PSQI). The effects of the clinical and PSG variables on the QOL score were analyzed using multiple stepwise regression analyses, and the QOL of OSA and SS groups was compared. RESULTS: In correlation analyses, the most significant factor that correlated with the QOL of the subjects was the PSQI total score (p < 0.001), while the AHI was not related to the WHOQOL-BREF total score. In multiple linear regression analysis, the PSQI total score was the most significant factor associated with the QOL of participants (p < 0.001). The mean score of the WHOQOL-BREF did not differ significantly between the OSA group and the SS group. CONCLUSION: This study suggests that the main factor affecting the QOL of suspected OSA subjects is their subjective sleep quality. We therefore conclude that patients with OSA symptoms estimate their QOL based on their subjective sleep perception rather than AHI.

Decreased regional gray matter volume in suicide attempters compared to suicide non-attempters with major depressive disorders.

OBJECTIVE: This study investigated regional gray matter (GM) volume differences between suicide attempters and suicide non-attempters with major depressive disorder (MDD) and their relationship with psychological risk factors for suicidality. METHODS: MDD patients with and without a suicide attempt history (n=19 in each group) participated. The Hamilton Depression Rating Scale, Clinical Global Impression (severity subscale), Scale for Suicide Ideation (SSI), Risk-Rescue Rating (RRR), Beck Hopelessness Scale (BHS), Barrett Impulsivity Scale, Eysenck Personality Questionnaire, and Ways of Coping Checklist (WCCL) were administered. T1-weighted structural magnetic resonance imaging scans were acquired to evaluate changes in GM volume. Voxel-based morphometry was performed using the SPM 8 software package. Two-sample t-tests were used during second-level group comparison analysis; partial correlation analysis controlling for gender and age identified associations between regional GM volume and psychological measures. RESULTS: Suicide attempters exhibited significantly decreased GM volume in the left angular gyrus (p<0.001, uncorrected) and right cerebellum (p<0.001, uncorrected). GM volume in the left angular gyrus was inversely correlated with BHS scores (r=-0.55, p<0.01) and positively correlated with the Seeking Social Support subscale of the WCCL (r=0.43, p<0.01). CONCLUSION: These findings provide evidence of a neural basis of suicidal behaviors in MDD. In particular, reduced GM volume in the left angular gyrus may be a neurobiological marker of suicidality in depressed patients.

The Association between Self-reported Sleep Duration and Body Mass Index among Korean Adolescents.

Previous research has shown that lack of sleep is related to Body Mass Index (BMI) in adolescence. This study was designed to investigate the association between sleep duration and BMI among Korean adolescents. We conducted a school-based cross-sectional study of 3,785 adolescents (males: 58.2%, females: 41.8%) in middle and high school between the ages of 11 and 18 years (mean age 15.26 ± 1.45). Using a self-reported questionnaire, we obtained information regarding weekday sleep duration, weekend sleep duration, height, weight, time spent at private tutoring institutes, socioeconomic status and scores on the Beck Depression Inventory (BDI). We investigated the association between self-reported sleep duration and BMI. After adjusting for confounding factors including age, gender, time spent at private tutoring institutes, academic performance, economic status and BDI scores, longer sleep duration on both weekdays and weekends was associated with decreased BMI (P = 0.002 and P < 0.001, respectively) for both genders. Increased weekend catch-up sleep duration was associated with decreased BMI in females (P = 0.038), but not in males (P = 0.343). The results of the present study indicated that longer sleep duration on weekdays and weekends in adolescents was associated with lower BMI. Longer weekend catch-up sleep may compensate effects of insufficient sleep on BMI for female adolescents.

DRD2 genotypic and haplotype variation is associated with improvements in negative symptoms after 6 weeks' amisulpride treatment.

The aim of this study was to identify the association between the rs1079597 and rs1800497 genetic polymorphisms of the gene encoding the dopamine D2 receptor (DRD2) protein and the treatment response to the selective dopamine receptor antagonist amisulpride. After 6 weeks of treatment with amisulpride, 125 schizophrenia patients were interviewed based on the Positive and Negative Syndrome Scale and the Clinical Global Impression-Severity Scale. Genotyping for rs1079597 and rs1800497 was performed using the TaqMan single nucleotide polymorphism genotyping assay. There were significant differences in the genotype frequency of the recessive model (χ = 5.73, P = 0.017) and allele frequency (χ = 5.16, P = 0.023) of rs1079597 between the responders and nonresponders based on the Positive and Negative Syndrome Scale negative symptoms scores. There was no significant finding in this regard for the rs1800497 polymorphism. The T-C and C-C haplotype of rs1079597-rs1800497 were associated with the negative symptom treatment response to amisulpride after permutation test. To the best of our knowledge, this is the first report of the positive finding in the association study between rs1079597 polymorphism and the treatment response to amisulpride in schizophrenic patients. A larger scale study involving more single nucleotide polymorphisms of DRD2 will progress the research into the pharmacogenetics of the treatment response to amisulpride.

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.

DRD3 gene rs6280 polymorphism may be associated with alcohol dependence overall and with Lesch type I alcohol dependence in Koreans.

BACKGROUND: Several polymorphisms of the dopamine D3 receptor (DRD3) gene are reported to be involved in the susceptibility to alcoholism. Although the DRD3 rs6280 (Ser9Gly) polymorphism plays an important role in various psychiatric disorders, findings regarding the association between this single-nucleotide polymorphism (SNP) and alcohol dependence (AD) have been inconsistent. Therefore, the present study investigated the association between the DRD3 gene rs6280 polymorphism with AD and Lesch type I AD in Korean subjects. METHODS: The DRD3 rs6280 SNP was genotyped in a case-control sample comprising 245 AD patients and 130 healthy controls (HCs). Alcohol Use Disorders Identification Test (AUDIT) scores were also compared relative to genotype in all of the participants. RESULTS: This SNP was significantly associated with both AD overall (χ(2) = 10.09 and p = 0.001, and χ(2) = 10.60 and p = 0.005, for the recessive and additive models, respectively) and with Lesch type I AD (χ(2) = 11.70 and p = 0.001, and χ(2) = 11.70 and p = 0.003, for the recessive and additive models, respectively). The allele frequency differed significantly (χ(2) = 8.45, p = 0.004) between Lesch type I AD and HC subjects. The AUDIT total (F = 6.56, p = 0.011), hazardous alcohol use (F = 7.12, p = 0.008), dependence symptoms (F = 5.10, p = 0.025), and harmful alcohol use (F = 4.83, p = 0.029) scores were significantly higher in those who did not possess the S allele (genotype GG) than in those who did (genotypes SS ± SG). CONCLUSIONS: The findings of this study suggest that the DRD3 rs6280 polymorphism is associated with the development of both AD overall and Lesch type I AD in Koreans.

Weekend catch-up sleep is independently associated with suicide attempts and self-injury in Korean adolescents.

The current study aims to determine the associations of insufficient sleep with suicide attempts and self-injury in a large, school-based Korean adolescent sample. A sample of 4553 middle- and high-school students (grades 7-10) was recruited in this study. Finally, 4145 students completed self-report questionnaires including items on sleep duration (weekday/weekend), self-injury, suicide attempts during the past year, the Suicidal Ideation Questionnaire (SIQ), and the Beck Depression Inventory (BDI). A multiple linear regression model showed that higher SIQ scores were associated with longer weekend catch-up sleep duration (p=0.009), higher BDI score (p<0.001), and longer time spent in a private educational institute (p=0.025). The multiple logistic regression analysis revealed that longer weekend catch-up sleep duration (p=0.011), higher BDI score (p<0.001), longer time spent in a private educational institute (p=0.046), and poorer academic record (p=0.029) were associated with suicide attempt and self-injury during the past year. The present results suggest that weekend catch-up sleep duration--which is an indicator of insufficient weekday sleep--might be associated with suicide attempts and self-injury in Korean adolescents.