Association of resting-state theta–gamma coupling with selective visual attention in children with tic disorders

A tic disorder (TD) is a neurodevelopmental disorder characterized by tics, which are repetitive movements and/or vocalizations that occur due to aberrant sensory gating. Its pathophysiology involves dysfunction in multiple parts of the cortico-striato-thalamo-cortical circuits. Spontaneous brain activity during the resting state can be used to evaluate the baseline brain state, and it is associated with various aspects of behavior and cognitive processes. Theta–gamma coupling (TGC) is an emerging technique for examining how neural networks process information through interactions. However, the resting-state TGC of patients with TD and its correlation with cognitive function have not yet been studied. We investigated the resting-state TGC of 13 patients with TD and compared it with that of 13 age-matched healthy children. The participants underwent resting-state electroencephalography with their eyes closed. At the global level, patients with TD showed a significantly lower resting-state TGC than healthy children. Resting-state TGC with the eyes closed was significantly negatively correlated with the attention quotient calculated for omission errors in a selective visual attention test. These findings indicate that the resting-state brain network, which is important for the attentional processing of visual information, is dysfunctional in patients with TD. Additionally, these findings support the view that TGC reflects information processing and signal interactions at the global level. Patients with TD may have difficulty gating irrelevant sensory information in the resting state while their eyes are closed.

Differential risk factors for prenatal and postpartum depression in South Korea

Introduction

Incidence for depression increases during the perinatal period. Risk factors for depression may differentially affect each time period.

Objectives

To assess demographic, psychological and obstetric risk factors that differentially affect prenatal and postpartum depression

Methods

A total of 169 subjects participated. Assessment was conducted during the first trimester, second trimester, third trimester, within a month after childbirth, and a month after childbirth. Demographic and obstetric measures, as well as psychological measures, including the Edinburgh Postnatal Depression Scale were conducted. Multiple regression and the Mann-Whitney U test were performed to examine the association between variables and depression scores.

Results

Depression score was higher during the postpartum period than the prenatal period. Younger age was associated with depression during the first trimester. In the second trimester, less education, a history of depression and having stress within a year significantly affected depression scores. Smoking, artificial abortion and lack of support from family and parents correlated with depression during the third trimester. Within a month after childbirth, psychiatric and depression history, smoking, stress level within a year and lack of family support were associated with depression. At a month after childbirth, those who were primiparous and not breastfeeding had significantly higher depression scores.

Conclusions

This study identifies various risk factors for each gestational and postpartum period and suggests differential interventions for different perinatal periods.

Deactivation of anterior cingulate cortex during virtual social interaction in obsessive-compulsive disorder

Studies about social functioning in obsessive-compulsive disorder (OCD) are lacking, even though neuroimaging studies and metacognition evaluation results suggest abnormal neural responses during social interactions. This study examined neural responses of OCD patients during handshakes with a virtual avatar. Because of the nature of the handshaking task, we expected that OCD patients with predominantly contamination/washing symptoms (CON) would show different neural responses compared to healthy controls (HCs) and to disease-controlled (NCON) patients. Thirteen CON, 13 NCON, and 18 HC participants performed handshake tasks with clean or dirty virtual avatars while undergoing functional magnetic resonance imaging. During handshakes with a clean avatar, deactivation in the left anterior cingulate cortex was found in CON patients compared to NCON and HC subjects. This cortical deactivation also occurred with dirty-avatar handshakes, but the difference was significant only between the two OCD groups and HC patients. Deactivation in the left anterior cingulate cortex was correlated with both OCD symptom severity and social anxiety traits. This cortical deactivation in OCD, especially in CON patients, suggests that social dysfunction in OCD may be due to interactions between OCD symptoms and impairment in social cognition, including emotional processing.

Defining Subtypes in Children with Nail Biting: A Latent Profile Analysis of Personality

OBJECTIVE

This study aimed to examine personality profiles and behavioral problems of children with nail biting (NB) to gain insight into the developmental trajectory of pathological NB.

METHODS

681 elementary school students were divided into non NB (n=436), occasional NB (n=173) and frequent NB group (n=72) depending on the frequency of NB reported in Child Behavioral Checklist (CBCL). Children's personality was assessed using the Junior Temperament and Character Inventory (JTCI), and behavioral problems were assessed using the CBCL. Latent Profile Analysis (LPA) was performed using JTCI profiles to classify personalities of the children with NB (belonging to frequent and occasional NB group, n=245).

RESULTS

For subscale scores of CBCL, the total, internalizing, externalizing, anxious/depressed withdrawn/depressed, depression, thought, rule-breaking, and aggressive behavior problems, were most severe in the frequent NB group followed by occasional NB and non NB group. LPA of personality profile in children with NB revealed four classes ('adaptiveness,' 'high reward dependence,' 'low self-directedness,' and 'maldaptiveness'). The four personality classes demonstrated significant group differences in all of the CBCL subscales. Children who showed low self-directedness and cooperativeness and high novelty seeking and harm avoidance personality profiles demonstrated highest tendency for problematic behavior irrespective of the frequency of NB.

CONCLUSION

Children with NB reported significantly more problematic behaviors compared to children without NB. Children with specific personality profile demonstrated higher tendency for problematic behavior irrespective of the frequency of NB. Therefore, accompanying personality profiles should be considered when assessing behavioral problems in children with NB.

Medical Help-Seeking Strategies for Perinatal Women With Obstetric and Mental Health Problems and Changes in Medical Decision Making Based on Online Health Information: Path Analysis

Background

Previous studies have revealed that most pregnant women rarely discuss informal information found on the internet with health professionals and have frequently expressed concerns for medical experts’ reactions to the online information they shared, as well as the lack of time to consult the medical experts in general. To date, little information is available on the effect of individual differences in utilizing medical help-seeking strategies on their medical decisions during the perinatal period.

Objective

The objectives of this study were (1) to determine associations among perinatal women’s medical help-seeking strategies, changes in medical decision making, and online health information utilization with a focus on the mediating effect of self-efficacy in perinatal health literacy on the intent to consult health professionals, and (2) to clarify these associations in perinatal women with two different medical problems: obstetric and mental health.

Methods

A total of 164 perinatal women aged 24 to 47 years (mean 34.64, SD 3.80) repeatedly completed the Problem Solving in Medicine and Online Health Information Utilization questionnaires to examine the moderating effect of two types of medical problems on their decision-making processes. To validate the hypothesized relationships in the proposed conceptual model encompassing obstetric and mental health problem-solving models, path analyses were performed.

Results

This study found that some perinatal women, who use an online informal medical help-seeking (OIMH) strategy, would be more likely to change their medical decisions based only on internet-based information without consulting health professionals (P<.001), compared to other women using different medical help-seeking strategies. Particularly, this concern is significantly prevalent when encountering obstetric problems during the perinatal period (obstetric problem-solving: P<.001; mental health problem-solving: P=.02). Furthermore, perinatal women with mental health issues using the OIMH strategy showed a significant difference in intent to consult health professionals based on online health information when the medical problem they had to solve was different (obstetric problem-solving: P=.94; mental health problem-solving: P=.003).

Conclusions

Despite the positive mediating effects of perinatal women’s enhanced health literacy on the intent to discuss personal medical issues with health professionals based on online health information, the strategy used is of fundamental importance for understanding their help-seeking and decision-making processes during the perinatal period. Beyond a short consultation to steer patients quickly and authoritatively towards an obstetric doctor’s choice of action, it is recommended in this study that obstetricians attempt to provide their patients with needed context for the information found online. To fully explain this information with an open mind, they should actively develop or support information and communications technology (ICT)-based health information services.

Response Time as an Implicit Self-Schema Indicator for Depression Among Undergraduate Students: Preliminary Findings From a Mobile App-Based Depression Assessment

Background

Response times to depressive symptom items in a mobile-based depression screening instrument has potential as an implicit self-schema indicator for depression but has yet to be determined; the instrument was designed to readily record depressive symptoms experienced on a daily basis. In this study, the well-validated Korean version of the Center for Epidemiologic Studies Depression Scale-Revised (K-CESD-R) was adopted.

Objective

The purpose of this study was to investigate the relationship between depression severity (ie, explicit measure: total K-CESD-R Mobile scores) and the latent trait of interest in schematic self-referent processing of depressive symptom items (ie, implicit measure: response times to items in the K-CESD-R Mobile scale). The purpose was to investigate this relationship among undergraduate students who had never been diagnosed with, but were at risk for, major depressive disorder (MDD) or comorbid MDD with other neurological or psychiatric disorders.

Methods

A total of 70 participants—36 males (51%) and 34 females (49%)—aged 19-29 years (mean 22.66, SD 2.11), were asked to complete both mobile and standard K-CESD-R assessments via their own mobile phones. The mobile K-CESD-R sessions (binary scale: yes or no) were administered on a daily basis for 2 weeks. The standard K-CESD-R assessment (5-point scale) was administered on the final day of the 2-week study period; the assessment was delivered via text message, including a link to the survey, directly to participants’ mobile phones.

Results

A total of 5 participants were excluded from data analysis. The result of polynomial regression analysis showed that the relationship between total K-CESD-R Mobile scores and the reaction times to the depressive symptom items was better explained by a quadratic trend—F (2, 62)=21.16, P<.001, R²=.41—than by a linear trend—F (1, 63)=25.43, P<.001, R²=.29. It was further revealed that the K-CESD-R Mobile app had excellent internal consistency (Cronbach alpha=.94); at least moderate concurrent validity with other depression scales, such as the Korean version of the Quick Inventory for Depressive Symptomatology-Self Report (ρ=.38, P=.002) and the Patient Health Questionnaire-9 (ρ=.48, P<.001); a high adherence rate for all participants (65/70, 93%); and a high follow-up rate for 10 participants whose mobile or standard K-CESD-R score was 13 or greater (8/10, 80%).

Conclusions

As hypothesized, based on a self-schema model for depression that represented both item and person characteristics, the inverted U-shaped relationship between the explicit and implicit self-schema measures for depression showed the potential of an organizational breakdown; this also showed the potential for a subsequent return to efficient processing of schema-consistent information along a continuum, ranging from nondepression through mild depression to severe depression. Further, it is expected that the updated K-CESD-R Mobile app can play an important role in encouraging people at risk for depression to seek professional follow-up for mental health care.

Discrepancies of Implicit and Explicit Self-Esteem as Predictors of Attributional Bias and Paranoia

OBJECTIVE

The current study aimed to examine the association of implicit self-esteem, explicit self-esteem and their interaction with paranoia and attributional bias. The relationship of the size and the direction of the discrepancy between implicit and explicit self-esteem with paranoia and attributional bias was examined.

METHODS

A total of 128 female college students participated. We administered the Implicit Association Test to assess implicit self-esteem, and the Rosenberg Self-Esteem Scale to measure explicit self-esteem. Paranoia Scale was used, and the attributional bias was assessed using the Ambiguous Intentions Hostility Questionnaire.

RESULTS

Results showed that explicit but not implicit self-esteem was negatively associated with paranoia, blame bias and hostility perception bias in ambiguous situations. The interaction of implicit and explicit self-esteem was associated with hostility perception in ambiguous situations. As for the discrepancy, the size of the discrepancy between implicit and explicit self-esteem was positively associated with hostility perception in ambiguous situations. Moreover, the direction of the discrepancy was specifically relevant: damaged self-esteem (high implicit and low explicit self-esteem) was associated with increased levels of paranoia, blame bias and hostility perception in ambiguous situations.

CONCLUSION

These findings provide new insights into the role of the implicit and explicit self-esteem in attributional bias and paranoia and point to damaged self-esteem as a possible vulnerability marker for illogical attribution of blaming others and perceiving hostility in social situations.

Predicting Working Memory Capacity in Older Subjects Using Quantitative Electroencephalography

OBJECTIVE

We utilized a spectral and network analysis technique with an integrated support vector classification algorithm for the automated detection of cognitive capacity using resting state electroencephalogram (EEG) signals.

METHODS

An eyes-closed resting EEG was recorded in 158 older subjects, and spectral EEG parameters in seven frequency bands, as well as functional brain network parameters were, calculated. In the feature extraction stage, the statistical power of the spectral and network parameters was calculated for the low-, moderate-, and high-performance groups. Afterward, the highly-powered features were selected as input into a support vector machine classifier with two discrete outputs: low- or high-performance groups. The classifier was then trained using a training set and the performance of the classification process was evaluated using a test set.

RESULTS

The performance of the Support Vector Machine was evaluated using a 5-fold cross-validation and area under the curve values of 70.15% and 74.06% were achieved for the letter numbering task and the spatial span task.

CONCLUSION

In this study, reliable results for classification accuracy and specificity were achieved. These findings provide an example of a novel method for parameter analysis, feature extraction, training, and testing the cognitive function of elderly subjects based on a quantitative EEG signal.

Relationship between chronotype and temperament/character among university students

Chronotype is largely classified as being morning or evening types according to preference for daily activity and the preferred bedtime. This study examined the relationship between chronotype and temperament/character dimensions among university students. A total of 2857 participants completed the 140-item Temperament and Character Inventory-Revised Short version (TCI-RS) from a 5-score scale as well as the 13-item composite scale for morningness-eveningness (CSM). In this study, we classified chronotype as "morning," "neither," or "evening" types according to CSM scores and compared the scores in terms of 4 temperament dimensions and 3 character dimensions. The evening type showed high values for novelty seeking and harm avoidance, whereas the morning type had high scores for persistence, self-directedness, and cooperativeness. A logistic regression analysis after controlling for age and gender showed that chronotype significantly associated with persistence and novelty seeking. The results of this study suggest that chronotype is different according to gender and age and in addition, chronotype closely correlates with temperament and character. Among these, eveningness was associated with high novelty seeking, whereas morningness was associated with high persistence. Further studies are required to investigate the relationship between chronotype and temperament/character dimensions in a wider age bracket.

The Relationship between Personality, Sense of Efficacy, and Stress in Korean Teachers

Several studies have linked teachers' personality characteristics and sense of efficacy to stress. However, investigating the relationship between these three constructs in this context was limited. This study aims to investigate the relationship between personality, sense of efficacy and perceived stress among Korean teachers. A total of 137 teachers working in elementary, middle, and high schools located in Seoul, South Korea were recruited for the study. The participants were administered Temperament and Character Inventory, Teacher's Sense of Efficacy Scale (TSES), and Perceived Stress Scale. The TSES was negatively correlated with harm avoidance and positively correlated with persistence, self-directedness, cooperativeness, and self-transcendence. Perceived stress was positively correlated with harm avoidance and negatively correlated with persistence and self-directedness. The path analysis showed that harm avoidance directly predicted perceived stress (β=0.37, 95% CI=0.21-0.53, p=0.002), and self-directedness and persistence predicted one's sense of efficacy (β=0.18, 95% CI=0.01-0.39 and β=0.31, 95% CI=0.10-0.47), which predicted perceived stress (β=-0.21, 95% CI=-0.39 to -0.02). The results of the present study indicate that harm avoidance might be associated with stress-proneness, while persistence, self-directedness, and sense of efficacy might act as protective resources against stress in Korean teachers.

Frontostriatal Connectivity Changes in Major Depressive Disorder After Repetitive Transcranial Magnetic Stimulation: A Randomized Sham-Controlled Study

OBJECTIVE

The aim of this randomized, sham-controlled study was to investigate the therapeutic effects of underlying neurobiological changes after 2-week repetitive transcranial magnetic stimulation (rTMS) treatment using functional connectivity magnetic resonance imaging in patients with major depression.

METHODS

Twenty-four patients with major depressive disorder diagnosed with DSM-IV-TR criteria were randomly assigned to the active rTMS (n = 13) or sham (n = 11) groups from January 2009 to June 2011. rTMS was given for 2 weeks at 110% of the motor threshold for 10 minutes at 10 Hz over the left dorsolateral prefrontal cortex (DLPFC). Resting state functional connectivity was evaluated before and after rTMS. The 17-item Hamilton Depression Rating Scale (HDRS) was administered, and neurocognitive tasks were performed. We examined between-group differences in functional connectivity changes from the bilateral DLPFC.

RESULTS

Participants in the active rTMS group showed significant clinical improvement in HDRS scores compared to those in the sham group (P < .001). After 2-week rTMS, there were significant differences in changes in DLPFC-left caudate connectivity (corrected P < .05): the active group showed a greater reduction of connectivity strength between the DLPFC and left caudate compared to the sham group. Reduced levels of DLPFC-left caudate connectivity predicted improvement in depressive symptoms (r = 0.58, P = .001). Additionally, a positive correlation between residual depressive symptoms and connectivity strength after 2-week rTMS was found (r = 0.46, P = .023).

CONCLUSIONS

High-frequency rTMS over the left DLPFC showed therapeutic effects in patients with major depression. The therapeutic effect of rTMS is related to the modulation of functional connectivity in the frontostriatal network.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01325831​.

Experiential pleasure deficits in the prodrome: A study of emotional experiences in individuals at ultra-high risk for psychosis and recent-onset schizophrenia

BACKGROUND

Previous studies report deficits in noncurrent but not current pleasure experience in schizophrenia, but little is known about pleasure experiences of the prodrome. This study investigated noncurrent and current pleasure experiences and its relationship with neurocognitive function and self-esteem in ultra-high risk (UHR) for psychosis and recent-onset schizophrenia (ROSPR).

METHODS

Twenty-four UHR, 25 ROSPR and 42 normal controls completed the physical and social anhedonia scales for noncurrent emotional experience and the laboratory-based assessment of valence and arousal evoked by positive, neutral and negative emotional stimuli for current emotional experience. Relationships of current and noncurrent emotional experience, episodic memory and self-esteem were investigated.

RESULTS

For ROSPR, noncurrent pleasure, but not current pleasure evoked by positive stimuli, was diminished. Noncurrent anhedonia in ROSPR was related to episodic memory deficits and low self-esteem. In UHR subjects, both noncurrent pleasure and current pleasure to positive and neutral stimuli were diminished. Noncurrent anhedonia in UHR was not associated with episodic memory nor self-esteem. For arousal, ROSPR patients showed higher arousal than UHR subjects to positive stimuli.

CONCLUSIONS

Findings indicate the presence of experiential hedonic deficits during the prodrome phase. Diminished noncurrent pleasure reports exist in ROSPR, which seems to be associated with cognitive deficits and low self-concept. Future research is needed to probe into further underlying mechanisms.

Further evidence of a dissociation between decision-making under ambiguity and decision-making under risk in obsessive-compulsive disorder

BACKGROUND

Deficits in decision-making have been suggested as a key concept in understanding the symptoms of obsessive-compulsive disorder (OCD). However, evidence in the extant literature remains inconclusive on whether patients with OCD show inferior performance on laboratory decision-making tasks. The aims of the present study were therefore to (1) assess decision-making under ambiguity and under risk in patients with OCD and (2) study the influence of neuropsychological and clinical variables on decision-making in OCD.

METHODS

The sample consisted of 65 patients with OCD and 58 controls. The Iowa gambling task (IGT) and the game of dice task (GDT) were used to examine decision-making under ambiguity and decision-making under risk, respectively. In addition, reversal learning and executive function were assessed in terms of their relationship with decision-making tasks.

RESULTS

Patients with OCD showed impairment in the IGT, but not in the GDT. Reversal learning was neither impaired nor correlated with IGT performance. Among the clinical variables, illness severity and depression were associated with IGT scores. Executive function was impaired, but no significant relationship was found between executive function and GDT performance in OCD patients.

LIMITATIONS

Almost all OCD patients were on medication when they performed decision-making tasks.

CONCLUSIONS

Patients with OCD are impaired in decision-making under ambiguity, but not under risk. These findings demonstrate that decision-making processes are dissociated in OCD.

Abnormal brain activity in social reward learning in children with autism spectrum disorder: an fMRI study

PURPOSE

We aimed to determine whether Autism Spectrum Disorder (ASD) would show neural abnormality of the social reward system using functional MRI (fMRI).

MATERIALS AND METHODS

27 ASDs and 12 typically developing controls (TDCs) participated in this study. The social reward task was developed, and all participants performed the task during fMRI scanning.

RESULTS

ASDs and TDCs with a social reward learning effect were selected on the basis of behavior data. We found significant differences in brain activation between the ASDs and TDCs showing a social reward learning effect. Compared with the TDCs, the ASDs showed reduced activity in the right dorsolateral prefrontal cortex, right orbitofrontal cortex, right parietal lobe, and occipital lobe; however, they showed increased activity in the right parahippocampal gyrus and superior temporal gyrus.

CONCLUSION

These findings suggest that there might be neural abnormality of the social reward learning system of ASDs. Although this study has several potential limitations, it presents novel findings in the different neural mechanisms of social reward learning in children with ASD and a possible useful biomarker of high-functioning ASDs.

Distinct functional connectivity of limbic network in the washing type obsessive-compulsive disorder

Neurobiological models of obsessive-compulsive disorder (OCD) emphasize disturbances of the corticostriatal circuit, but it remains unclear as to how these complex network dysfunctions correspond to heterogeneous OCD phenotypes. We aimed to investigate corticostriatal functional connectivity alterations distinct to OCD characterized predominantly by contamination/washing symptoms. Functional connectivity strengths of the striatal seed regions with remaining brain regions during the resting condition and the contamination symptom provocation condition were compared among 13 OCD patients with predominant contamination/washing symptoms (CON), 13 OCD patients without these symptoms (NCON), and 18 healthy controls. The CON group showed distinctively altered functional connectivity between the ventral striatum and the insula during both the resting and symptom-provoking conditions. Also, the connectivity strength between the ventral striatum and the insula significantly correlated with contamination/washing symptom severity. As common connectivity alterations of the whole OCD subjects, corticostriatal circuits involving the orbitofrontal and temporal cortices were again confirmed. To our knowledge, this is the first study that examined specific abnormalities in functional connectivity of contamination/washing symptom dimension OCD. The findings suggest limbic network dysfunctions to play a pivotal role in contamination/washing symptoms, possibly associated with emotionally salient error awareness. Our study sample allowed us to evaluate the corticostriatal network dysfunction underlying the contamination/washing symptom dimension, which leaves other major symptom dimensions to be explored in the future.

Abnormalities of emotional awareness and perception in patients with obsessive-compulsive disorder

BACKGROUND

Emotional awareness deficit may play a critical role in the production and maintenance of obsessive-compulsive symptoms and social dysfunction in patients with obsessive-compulsive disorder (OCD). The aim of this study was to investigate characteristics of emotional awareness such as empathy and alexithymia in OCD patients. In addition, we examined whether impaired emotional awareness measured by self-assessment questionnaires was associated with emotional facial recognition ability in OCD patients.

METHODS

Study participants included 107 patients with OCD and 130 healthy age- and sex-matched volunteers. The Interpersonal Reactivity Index (IRI) and Toronto Alexithymia Scale-20 were applied as measures of empathy and alexithymia. A subset of 56 patients with OCD additionally performed the emotional perception task of face expression.

RESULTS

Patients with OCD scored significantly lower for perspective taking, and significantly higher for personal distress of IRI, and significantly higher for alexithymia compared to normal controls. Impaired emotional awareness such as lower perspective taking and fantasy seeking had a perception bias towards disgust in response to ambiguous facial expressions in OCD patients.

LIMITATIONS

The OCD group consisted of patients in different stages of the illness and with different degrees of severity.

CONCLUSIONS

OCD involves the impairment of emotional awareness and perception and it may relate to social dysfunction and to impairments in the ability to shift naturally from obsessive thoughts to other thoughts in response to social situations in patients with OCD.

Psychometric analysis of the Korean version of the Disgust Scale-Revised

OBJECTIVE

Disgust is a basic emotion associated with feelings of revulsion and withdrawal behaviors from dangerous situations. The aim of this study was to examine the psychometric properties of the Disgust Scale--Revised (DS-R), a tool designed to measure individuals' responses to various disgust-provoking situations, among Korean populations.

METHODS

A sample of 1117 healthy volunteers completed self-report questionnaires containing the 27-item DS-R. A subsample (n = 231) completed the Temperament and Character Inventory (TCI), Eysenck Personality Questionnaire (EPQ), and State-Trait Anxiety Inventory (STAI). Principal component analysis using a varimax rotation was conducted. Construct validity was assessed using Pearson correlation analysis for the TCI, EPQ, and STAI. To examine differences in responses on the DS-R among populations, patients with obsessive-compulsive disorder were compared with healthy subjects who were matched with respect to age and sex.

RESULTS

The Cronbach α estimates for total items and the 3 original subscales of the DS-R, including: core disgust, animal reminder disgust, and contamination-based disgust, were 0.86, 0.77, 0.80, and 0.55, respectively. Principal component analysis identified 5 factors, which accounted for 48% of the total variance of the scale. The 5 newly developed dimensions were labeled as core disgust-touch, core disgust-dirt, contamination-based disgust, animal reminder disgust, and social intolerance disgust. The Cronbach α coefficients were 0.79, 0.64, 0.46, 0.77, and 0.34, respectively, for these subscales. The DS-R was correlated positively with harm avoidance from the TCI, neuroticism from the EPQ, and the anxiety scores of STAI. Furthermore, the contamination-based disgust scores for patients with obsessive-compulsive disorder were higher than those of normal controls.

CONCLUSION

The DS-R may be a reliable, valid, and acceptable tool to measure disgust sensitivity among Korean populations. The psychometric properties of the Korean version of the DS-R and the original DS-R are discussed.

The 1287 G/A polymorphism of the norepinephrine transporter gene (NET) is involved in commission errors in Korean children with attention deficit hyperactivity disorder

Background

Previous evidence supports the role of noradrenergic systems in ADHD, and norepinephrine transporter (NET) is critical in regulating the noradrenergic system. The present study aimed to investigate the association between NET gene polymorphism and the performance measures of the Continuous Performance Test (CPT) in Korean ADHD children.

Methods

Eighty-seven children (mean age = 9.23 ± 1.99 years) with ADHD were recruited from a university hospital. Genotypes of G1287A of the NET gene (SLC6A2) were analyzed. All participants completed the CPT, with performance measures of omission errors, commission errors, reaction time and reaction standardization computed. The relationship between G1287A polymorphisms and CPT performance measures was examined.

Results

There were 46 subjects with the G/G genotype, 35 subjects with the G/A genotype and 6 subjects with the A/A genotype. Among the three groups, there were no significant differences in the performance of CPTs. When dichotomized according to whether the subjects have the rare allele or not, subjects with the homozygous G/G genotype showed significantly lower commission errors compared to those without G/G genotypes (by independent T-test, t = -2.18, p = 0.026).

Discussion

Our study found a significant association between commission errors of the CPT and the G1287A genotype of the NET gene in Korean ADHD children. These findings suggest a protective role of the G/G genotype of the NET polymorphisms in the deficits of response inhibition in ADHD children.

Perception bias of disgust in ambiguous facial expressions in obsessive-compulsive disorder

Impaired recognition of facial expressions of disgust has been suggested for patients with obsessive-compulsive disorder (OCD). This study aimed to compare the perception of negative emotions by OCD patients and controls using both non-ambiguous and ambiguous facial expressions. Forty-one OCD patients and thirty-seven controls performed the computerised emotion perception task. There were no differences between OCD patients and controls in the frequency of correct identification of non-ambiguous facial expressions. However, OCD patients were more likely to perceive disgust and less likely to perceive anger in response to ambiguous facial expressions when controlling for covariates. In OCD patients, a higher cleaning dimension was associated with a lower perception of anger and a higher perception of disgust when presented with ambiguous facial expressions. The domains of core disgust and contamination-based disgust domains of disgust sensitivity were positively correlated with the perception of ambiguous facial expressions as disgust, as well as cleaning symptom dimension scores. Our findings suggest that OCD patients, particularly those with higher washing/contamination symptoms, are more likely to perceive disgust in ambiguous facial expressions.