Impact of data extraction errors in meta-analyses on the association between depression and peripheral inflammatory biomarkers: an umbrella review.

BACKGROUND: Accumulating evidence suggests that alterations in inflammatory biomarkers are important in depression. However, previous meta-analyses disagree on these associations, and errors in data extraction may account for these discrepancies. METHODS: PubMed/MEDLINE, Embase, PsycINFO, and the Cochrane Library were searched from database inception to 14 January 2020. Meta-analyses of observational studies examining the association between depression and levels of tumor necrosis factor-α (TNF-α), interleukin 1-ß (IL-1ß), interleukin-6 (IL-6), and C-reactive protein (CRP) were eligible. Errors were classified as follows: incorrect sample sizes, incorrectly used standard deviation, incorrect participant inclusion, calculation error, or analysis with insufficient data. We determined their impact on the results after correction thereof. RESULTS: Errors were noted in 14 of the 15 meta-analyses included. Across 521 primary studies, 118 (22.6%) showed the following errors: incorrect sample sizes (20 studies, 16.9%), incorrect use of standard deviation (35 studies, 29.7%), incorrect participant inclusion (7 studies, 5.9%), calculation errors (33 studies, 28.0%), and analysis with insufficient data (23 studies, 19.5%). After correcting these errors, 11 (29.7%) out of 37 pooled effect sizes changed by a magnitude of more than 0.1, ranging from 0.11 to 1.15. The updated meta-analyses showed that elevated levels of TNF- α, IL-6, CRP, but not IL-1ß, are associated with depression. CONCLUSIONS: These findings show that data extraction errors in meta-analyses can impact findings. Efforts to reduce such errors are important in studies of the association between depression and peripheral inflammatory biomarkers, for which high heterogeneity and conflicting results have been continuously reported.

Dorsal striatal functional connectivity changes in Internet gaming disorder: A longitudinal magnetic resonance imaging study.

Internet gaming disorder (IGD) is a behavioral addiction involving excessive online game use despite negative psychosocial consequences. Unrestricted online gaming may lead to changes in striatal activity and the relationship between the striatum and other cortical regions. This study investigated structural and functional abnormalities involving the striatum through longitudinal follow-up magnetic resonance imaging (MRI) assessments. Eighteen young males with IGD (mean age: 23.8 ± 2.0 years) and 18 controls (mean age: 23.9 ± 2.7 years) were evaluated. Subjects were reassessed ≥1 year after the first visit (mean follow-up duration: 22.8 ± 6.7 months), using voxel-based morphometry and seed-based resting-state functional connectivity (FC) analyses in seed regions of the dorsal and ventral striatum. Subjects with IGD had smaller gray matter volume (GMV) in the anterior/middle cingulate cortex compared with controls during initial and follow-up assessments. They exhibited decreased FC between the left dorsal putamen and left medial prefrontal cortex (mPFC) compared with controls. They exhibited increased FC strength between the right dorsal putamen and right middle occipital gyrus (MOG) during follow-up. Subjects with IGD showed a significant correlation between changes in the dorsal putamen-MOG FC and gaming time per day. Young males with IGD showed an altered FC pattern in the dorsal striatum during follow-up. FC of the dorsal striatum in IGD increased in the mPFC and decreased in the MOG. These findings showed that IGD was accompanied by weakening of prefrontal control and strengthening of the sensorimotor network, suggesting that uncontrolled gaming may be related with functional neural changes in the dorsal striatum.

Associations of systemic inflammation with frontotemporal functional network connectivity and out-degree social-network size in community-dwelling older adults.

Increasing evidence suggests that systemic inflammation adversely affects social experiences and behaviors of older adults by changing the functional state of the brain. In this study, we investigated the relationships among systemic inflammation, functional network connectivity (FNC) of the whole brain, and social-network size using complete social-network data of older adults residing in a Korean village. Sixty-one participants were recruited from the Korean Social Life, Health, and Aging Project (KSHAP). Participants underwent a resting-state functional magnetic resonance imaging scan. High sensitivity C-reactive protein (hs-CRP) levels were measured as an inflammation marker. In-degree and out-degree network sizes were calculated based on the total number of intimate social relationships per participant. We demonstrated that hs-CRP levels were associated with decreased frontotemporal FNC. Stronger frontotemporal FNC was significantly correlated with a larger out-degree network size, suggesting that impaired frontotemporal communication in older adults decreases perceived social connectedness with other people. An exploratory mediation analysis supported the observation that increased systemic inflammation contributes to reduced out-degree social-network size among older adults by changing frontotemporal FNC. The present findings provide meaningful insight into the complex relationship between systemic inflammation and social quality of life.

Abnormal gray matter volume and impulsivity in young adults with Internet gaming disorder.

Reduced executive control is one of the central components of model on the development and maintenance of Internet gaming disorder (IGD). Among the various executive control problems, high impulsivity has consistently been associated with IGD. We performed voxel-based morphometric analysis with diffeomorphic anatomical registration by using an exponentiated Lie algebra algorithm (DARTEL) to investigate the relationship of gray matter abnormalities to impulsivity in IGD. Thirty-one young male adults whose excessive Internet gaming began in early adolescence, and 30 age-matched male healthy controls were examined. IGD subjects showed smaller gray matter volume (GMV) in brain regions implicated in executive control, such as the anterior cingulate cortex and the supplementary motor area. The GMVs in the anterior cingulate cortex and the supplementary motor area were negatively correlated with self-reporting scales of impulsiveness. IGD subjects also exhibited smaller GMV in lateral prefrontal and parietal cortices comprising the left ventrolateral prefrontal cortex and the left inferior parietal lobule when compared with healthy controls. The GMVs in the left ventrolateral prefrontal cortex were negatively correlated with lifetime usage of Internet gaming. These findings suggest that gray matter abnormalities in areas related to executive control may contribute to high impulsivity of young adults with IGD. Furthermore, alterations in the prefrontal cortex were related with long-term excessive Internet gaming during adolescence.

Cholinesterase Inhibitor Donepezil Increases Mitochondrial Biogenesis through AMP-Activated Protein Kinase in the Hippocampus.

OBJECTIVE: Donepezil, a widely prescribed drug for Alzheimer's disease (AD), is now considered to have multimodal actions beyond cholinesterase inhibition. We aimed to see whether donepezil enhances mitochondrial biogenesis and relevant signaling pathways since mitochondrial dysfunction is a key feature of the hypometabolic AD brain. METHODS: As a metabolic gauge, AMP-activated protein kinase (AMPK) was investigated as a tentative mediator of neurometabolic action of donepezil. Changes in phospho-AMPK levels, mitochondrial biogenesis, and ATP levels were measured upon donepezil treatment using neuroblastoma cells, primary cultured neurons and ex vivo hippocampal tissue of adult mice. RESULTS: Donepezil dose-dependently increased mitochondrial biogenesis and ATP levels as well as expression of PGC-1α and NRF-1 in neuroblastoma cells. Donepezil dose-dependently activated AMPK; however, inhibition of AMPK abolished the observed effects of donepezil, indicating that AMPK is a key mediator of donepezil's action. Notably, mitochondrial biogenesis upon donepezil treatment was mainly observed within dendritic regions of primary cultured hippocampal neurons. Levels of synaptic markers were also increased by donepezil. Finally, AMPK- dependent mitochondrial biogenesis by donepezil was confirmed in organotypic hippocampal tissue. CONCLUSIONS: Our findings indicate that AMPK/PGC-1α signaling is involved in beneficial actions of donepezil on neurometabolism. Pharmacological activation of AMPK might be a promising approach to counteract AD pathogenesis associated with brain hypometabolism.

Synchrony of anterior cingulate cortex and insular-striatal activation predicts ambiguity aversion in individuals with low impulsivity.

Personal attitude toward ambiguity contributes to individual differences in decision making in uncertain situations. Operationally, these attitudes reflect the various coping strategies elected to overcome the limited information. A key brain region involved in cognitive control for performance adjustments is the dorsal anterior cingulate cortex (dACC). To test how dACC functional network connectivity would be modulated by uncertainty and differ between individuals, 24 healthy participants underwent functional MRI in 3 sequential runs: 1 resting-state and 2 decision-making task runs. Individuals with lower nonplanning impulsiveness made greater use of a Pass option and avoided uncertain ambiguous situations. Seed-based functional connectivity analysis during the task runs revealed that stronger activation synchrony between the left dACC and the right anterior insula correlated with greater use of a Pass response option. During the resting-state, stronger resting-state functional connectivity between the left dACC and the ventral striatum predicted the adoption of Pass as a behavioral strategy and correlated with stronger task-activated synchrony between the dACC and the right anterior insula. Our findings indicate that that the synchrony between the dACC and insula-striatal circuitry was greater in individuals with low compared with high nonplanning impulsiveness and contributed to adopting Pass as a useful behavioral strategy.

The relationship between parental marital status and suicidal ideation and attempts by gender in adolescents: results from a nationally representative Korean sample.

OBJECTIVE: Suicide in adolescents is a major problem worldwide. The purpose of this study was to identify differences in suicidal behaviors with respect to parental marital status. METHODS: The data used in this study were obtained from the Korea Youth Risk Behavior Web-based Survey (KYRBWS) of middle and high school students in 2010. Using a national representative sample, this study analyzed data from 73,238 subjects. With respect to gender, the odds ratios of suicidal behavior were calculated based on the parental marital status, living situation, and family affluence scale (FAS). RESULTS: After adjusting for age, achievement, sadness, and substance use, the prevalence of suicidal ideation in adolescents with a remarried parent significantly increased among boys to 1.364 [95% confidence interval (CI)=1.027-1.813] and among girls to 1.511 (95% CI=1.215-1.879). The odds ratio of suicide attempts increased to 1.808 (95% CI=1.119-2.923) for adolescent boys and to 1.947 (95% CI=1.609-2.356) for adolescent girls. However, having a single parent did not affect the prevalence of suicidal ideation in either gender. In girls, as family affluence decreased, the odds ratio of suicidal ideation notably increased. For girls whose families were in a low tier of the FAS, the odds ratio of both suicidal ideation and suicide attempts increased. CONCLUSIONS: Both boys and girls were more likely to report suicidal ideation and attempts after a parent's remarriage, whereas family affluence was inversely related to suicidal ideation and attempts in girls.

Genetic influence of COMT and BDNF gene polymorphisms on resilience in healthy college students.

PURPOSE: Resilience refers to the individual positive capacity to cope with stress and to restore homeostasis, which may be mediated by adaptive neurobiological changes in the brain. We investigated the genetic influence of the catechol-O-methyltransferase (COMT) Val158Met and the brain-derived neurotrophic factor (BDNF) Val66Met for individual differences in resilience in healthy Korean college students. METHODS: A sample of 321 healthy college volunteers (167 males, 154 females) was assessed by genotyping and with the 25-item Connor-Davidson Resilience Scale. Two-way analysis of covariance was used to test the association between participants' COMT and BDNF functional polymorphisms and their resilience. RESULTS: A significant main effect of the COMT polymorphism on resilience and a gene-gene interaction effect between the COMT and BDNF on resilience were observed for males. Male subjects with the COMT Met-present genotype had a significantly higher resilience than those with the Val/Val genotype. Among males with the COMT Val/Val genotype, subjects with the homozygous Val allele of the BDNF tended to have lower resilience than the BDNF Met carriers, while among males with the COMT Met-present genotype, those with the homozygous Val allele of the BDNF tended to have higher resilience than BDNF Met carriers. No main or interaction effects of the COMT and BDNF on resilience were observed for females. CONCLUSION: These findings suggest the effects of COMT Val158Met polymorphism on resilience could be modulated by BDNF Val66Met polymorphism in males.

Neural evidence for emotional involvement in pathological alcohol craving.

AIMS: Reducing craving is a key to success in the treatment of alcohol dependence. The emotion circuit may be involved in pathological craving for alcohol. In this study, we investigated neural correlates of emotional involvement in craving in alcohol dependence. METHODS: The study included 17 detoxified alcoholic patients and 25 social drinkers. We used functional magnetic resonance imaging to examine brain activation (blood oxygen level-dependent signals) while participants reported craving and emotion in response to visually presented, alcohol-related stimuli and emotional stimuli. RESULTS: In the craving-rating paradigm, negative emotional stimuli as well as alcohol cues activated craving-related brain regions in alcoholic patients. Activations of the inferior parietal lobule and dorsolateral prefrontal cortex by negative emotional stimuli were negatively correlated with craving; meanwhile limbic activation was positively correlated with craving. For the emotion paradigm, greater limbic activation was evident by alcohol-related stimuli in the alcohol-dependent group. CONCLUSIONS: Our findings constitute neural evidence for emotional involvement in pathological craving for alcohol, underscoring the importance of emotion management in abstinent alcoholic patients for relapse prevention.

Body image, sexual function and depression in Korean patients with breast cancer: modification by 5-HTT polymorphism.

BACKGROUND: Nearly 50% of women with breast cancer show depressive symptoms after diagnosis and treatment. The purpose of this study was to clarify how psychosocial factors (body image, sexuality, and social relationships) and genetic factors (functional polymorphism of the serotonin transporter-linked promoter region) influence depression. METHODS: The participants were categorized by DSM-IV diagnoses; scored according to their depressive symptoms, body image and social and sexual function (BIRS), self-esteem, and quality of life; and genotyped by functional polymorphism of the serotonin transporter promoter. RESULTS: Patients with depressive symptoms showed low self-esteem, poor body image, relationship problems, and low quality of life. Genotype frequencies did not differ between two groups categorized by the presence or absence of depressive symptoms. However, the patients with the short allele of the 5-HTTLPR had significantly higher HAM-D scores (F = 7.59, p = 0.047). CONCLUSION: The results suggest that psychosocial factors related to breast cancer treatment such as body image, self-esteem, and interpersonal relationship influence the development of depressive symptoms. The 5-HTTLPR may be associated with the severity of depressive symptoms rather than susceptibility to the development of depressive symptoms.

Theory of mind and hair cortisol in healthy young adults: the moderating effects of childhood trauma.

Background: Experiences of negative social interactions and childhood trauma (CT) can lead to aberrant hypothalamic-pituitary-adrenal functions. Poor theory of mind (ToM) ability is related to increased social stress levels; however, studies on the relationship between ToM and cortisol remain scarce. Objective: This study aimed to evaluate the relationship between ToM and the hair cortisol concentration (HCC) in healthy young adults considering the moderating role of CT. Method: A total of 206 healthy young adults were divided into two groups based on an experience of moderate-to-severe childhood trauma (CT+ and CT-). To determine whether CT moderated the relationship between ToM and HCC, moderation analysis was conducted controlling for age, sex, years of education, and scores of perceived stress, depression, and anxiety. Results: CT+ individuals reported higher subjective stress perception and depressive symptoms than CT- individuals, whereas anxiety-related symptoms, ToM, and HCC were not different between the groups. The experience of CT significantly moderated the relationship between ToM and HCC. The association between poorer ToM ability and higher HCC was significant only in CT+ group. Conclusion: CT is a moderator of the association between ToM and HCC, indicating the importance of CT in social cognition and the stress response.

Antecedentes: Las experiencias de interacciones sociales negativas y el trauma infantil (CT por sus siglas en inglés) pueden conducir a funciones hipotalámicas-pituitarias-adrenales aberrantes. La pobre capacidad de teoría de la mente (ToM por sus siglas en inglés) está relacionada con mayores niveles de estrés social; sin embargo, los estudios sobre la relación entre ToM y cortisol siguen siendo escasos.Objetivo: Este estudio tuvo como objetivo evaluar la relación entre ToM y concentración de cortisol en el cabello (HCC por sus siglas en inglés) en adultos jóvenes sanos considerando el papel moderador del CT.Método: Un total de 206 adultos jóvenes sanos se dividieron en dos grupos en función de una experiencia de trauma infantil de moderada a severa (CT+ y CT­). Para determinar si el CT moderaba la relación entre ToM y HCC, se realizó un análisis de moderación controlando la edad, sexo, años de educación y las puntuaciones de estrés percibido, depresión y ansiedad.Resultados: Individuos CT+ informaron una mayor percepción subjetiva de estrés y síntomas depresivos que los individuos CT­, mientras que los síntomas relacionados con ansiedad, ToM y HCC no fueron diferentes entre los grupos. La experiencia de CT moderó significativamente la relación entre ToM y HCC. La asociación entre una capacidad de ToM más pobre y un HCC más alto fue significativa solo en el grupo CT+.Conclusión: CT es un moderador de la asociación entre ToM y HCC, lo que indica la importancia del CT en la cognición social y la respuesta al estrés.

The effects of serotonin transporter promoter and monoamine oxidase A gene polymorphisms on trait emotional intelligence.

OBJECTIVE: The purpose of this study was to evaluate the influences of major serotonin-related genetic variants of the serotonin transporter-linked promoter region (5-HTTLPR), tryptophan hydroxylase 1 gene (TPH1) and monoamine oxidase A gene (MAOA-EcoRV) on trait emotional intelligence (EI). METHODS: The Trait Meta-Mood Scale (TMMS) measuring trait EI and genotyping were performed in 336 healthy Korean college students (204 males, 132 females). RESULTS: Among the male participants, those with the T genotype of MAOA (lower MAOA activity) had significantly lower subscale scores on the TMMS than those with the C genotype (higher MAOA activity) did. Additionally, male participants with the s/s genotype of the 5-HTTLPR gene had significantly lower attention subscale scores and total TMMS scores than those with the non-s/s (l/l + l/s) genotypes did. Among the female participants, there were no associations between any of the 5-HTTLPR, TPH1 or MAOA-EcoRV polymorphisms and any of the TMMS scores. CONCLUSION: These findings suggest a potential genetic basis of EI with regard to attention to one's own feelings involving the serotonin system in males.

Altered functional connectivity of the dorsal attention network among problematic social network users.

Many smartphone users spend excessive amounts of time online and cannot control their behavior, and the addictive overuse of social-networking services has been shown to be associated with diminished executive control. Attentional control is a cognitive process crucial to exerting executive functions. The purpose of this study was to investigate functional connectivity (FC) characteristics of attention networks in problematic social-network users. We performed seed-based resting-state FC analyses for 29 males and 10 females with excessive social network use and 32 healthy males and 17 healthy females. The right intraparietal sulcus and frontal eye fields were considered seeds of the dorsal attention network (DAN), and the right temporoparietal junction and ventral frontal cortex were considered seeds of the ventral attention network (VAN). Clinical characteristics predictive of FC findings in problematic social network users were identified through hierarchical multiple regression analysis. In FC analysis with DAN seeds, FC between the right intraparietal sulcus and the right middle occipital gyrus was stronger in problematic social network users than in controls, and FC between the right frontal eye field and the right dorsolateral prefrontal cortex was weaker than that in controls. There was no significant difference between the groups in FC analysis with VAN seeds. Hierarchical regression analyses showed that usage times on social networking platforms significantly predicted the negative effects on the strength of FC between the intraparietal sulcus and the dorsolateral prefrontal cortex. These findings indicated that problematic social network use reflects changes in the neural circuits underlying attentional control. Weaking of prefrontal control for attention networks would have a significant impact on failure to control one's time spent on social networks.

Altered Functional Connectivity of the Salience Network in Problematic Smartphone Users.

Smartphones provide convenience in everyday life. Smartphones, however, can elicit adverse effects when used excessively. The purpose of this study was to examine the underlying neurobiological alterations that arise from problematic smartphone use. We performed resting state seed-based functional connectivity (FC) analysis of 44 problematic smartphone users and 54 healthy controls. This analysis assessed the salience, central executive, default mode, and affective networks. Compared to controls, problematic smartphone users showed enhanced FC within the salience network and between the salience and default mode network. Moreover, we observed decreased FC between the salience and central executive network in problematic smartphone users, compared to controls. These results imply that problematic smartphone use is associated with aberrant FC in key brain networks. Our results suggest that changes in FC of key networks centered around the salience network might be associated with problematic smartphone use.

Increased resting-state cerebellar-cortical connectivity in breast cancer survivors with cognitive complaints after chemotherapy.

Cognitive complaints after chemotherapy are common in breast cancer patients, but the neural bases for these complaints remain unclear. This pilot study explored resting-state functional connectivity (FC) as a marker of subtle cognitive changes in breast cancer patients who experience cognitive complaints. Chemotherapy-treated (n = 20, at least 6 months off therapy) and untreated (n = 17, disease-control) female breast cancer patients with cognitive complaints and healthy controls (n = 20) were recruited. The FC of the right dorsolateral prefrontal cortex was calculated, and any correlations between this FC and neuropsychological assessments were determined. Chemotherapy-treated patients with cognitive complaints displayed increased FC between the right dorsolateral prefrontal cortex and both the contralateral cerebellar lobule VII and the cerebellar vermis XI, compared to the disease-control and healthy-control groups, despite unimpaired neuropsychological performance. The increased FC was negatively correlated with executive function and attention in breast cancer survivors with cognitive complaints. Our pilot study findings provide evidence that cerebellar-cortical FC changes may be a pathophysiological basis for chemotherapy-related cognitive complaints. In addition, the FC changes have the potential to reflect minor or compensated cognitive function impairment in breast cancer patients.

Diminished cognitive control in Internet gaming disorder: A multimodal approach with magnetic resonance imaging and real-time heart rate variability.

OBJECTIVE: Recently, the addiction to online games, classified as Internet gaming disorder (IGD) on DSM-V, has emerged as an important mental health problem. The loss of control over gaming in IGD is associated with diminished cognitive control. This study aimed to link the neurobiological mechanism reflected by brain imaging and the diminished cognitive control reflected by heart rate variability (HRV) measurements during real-time gameplay. METHODS: HRV was assessed in 33 young males with IGD and 29 controls while playing their favorite games. Seed-based functional connectivity (FC) was evaluated in the dorsolateral prefrontal cortex, anterior cingulate cortex, and dorsal striatum. Associations between HRV and alterations in FC were tested. RESULTS: Individuals with IGD showed a reduction of high-frequency HRV during real-time gaming, which is correlated with self-reported severity of IGD. Subjects with IGD showed decreased FC between the right dorsolateral prefrontal cortex and the right inferior frontal gyrus, corresponding to the cognitive control network. They showed decreased FC between the right anterior cingulate cortex and the superior parietal lobule. They also showed increased FC between the left dorsal putamen and the postcentral gyrus, corresponding to the sensorimotor network. Game-related high-frequency HRV was correlated with dorsolateral prefrontal cortex-inferior frontal gyrus connectivity. CONCLUSION: The diminished cognitive control reflected by HRV measurements during real-time gameplay was associated with FC alterations, involving a weak FC in the cognitive control network. Individuals with IGD may have less cognitive control, particularly when playing games, and consequently end up playing games in a habitual manner rather than in a goal-oriented manner.

Association of DRD4 and COMT polymorphisms with disgust sensitivity in healthy volunteers.

BACKGROUND: Disgust is a basic emotion that involves feelings of revulsion and withdrawal behavior from dangerous/infectious situations. Very little is known about the genetic basis of disgust sensitivity. The dopamine receptor D4 (DRD4) and catechol-O-methyltransferase (COMT) genes have been implicated in neuroticism-related traits and approach-related temperaments which are supposed to be associated with disgust sensitivity. The present study aimed to investigate the possible relationship between disgust sensitivity and COMT Val158Met and DRD4 variable number of tandem repeats (VNTR) polymorphisms in healthy subjects. METHODS: In total, 241 healthy Korean college students were recruited, and the 228 participants with a complete data set (127 males and 101 females) were included in the data analysis. Disgust sensitivity was assessed using the Disgust Scale-Revised (DS-R) and genotyping of COMT Val158Met and DRD4 VNTR polymorphisms was performed. RESULTS: The Val/Val groups of COMT had significantly higher scores than the non-Val/Val group for the Animal-Reminder and the Contamination-Based Disgust scores as well as for total DS-R scores. Additionally, the non-2-repeat allele group of DRD4 had a tendency to a significantly higher disgust sensitivity than the 2-repeat allele group for Contamination-Based Disgust. CONCLUSIONS: These findings suggest that disgust sensitivity may be affected by genetic components, such as dopamine-related genes.

Mammillothalamic functional connectivity and memory function in Wernicke's encephalopathy.

There is still debate over the neural mechanisms underlying pathogenic and even recovery processes of Wernicke's encephalopathy. Therefore, we attempted to validate the usefulness of resting-state functional connectivity analysis in assessing memory function and its neural correlation with the mammillothalamic tract in patients recovering from Wernicke's encephalopathy. Seven chronic alcoholics recovering from Wernicke's encephalopathy, 14 alcoholic comparisons without Wernicke's encephalopathy, and 14 healthy comparisons underwent functional connectivity MRI scans, as well as verbal and non-verbal memory tests after at least a 1 month abstinence from alcohol. Resting-state functional connectivity strength between the anterior thalamus and the mammillary bodies was investigated by calculating temporal correlations in magnetic resonance signal levels between the two regions during a 5-min passive viewing task. The mean values of the functional connectivity strength between the left anterior thalamus and the ipsilateral mammillary body differed significantly between Wernicke's encephalopathy patients and healthy comparisons (P = 0.014). This connectivity strength in alcoholic comparisons fell between those of the former two groups, with a significant difference from that of healthy comparisons (P = 0.038). In addition, the strength of this left-sided functional connectivity significantly correlated with delayed verbal recall scores (r = 0.771, P = 0.042) and verbal recognition score (r = 0.825, P = 0.022) in patients with Wernicke's encephalopathy. Our findings indicate that memory function in patients recovering from Wernicke's encephalopathy parallels the level of the mammillothalamic functional connectivity; this supports the usefulness of resting-state functional connectivity analysis as a practical alternative to pathological examination of the mammillothalamic tract in living patients with Wernicke's encephalopathy.

Interaction effects between COMT and BDNF polymorphisms on boredom susceptibility of sensation seeking traits.

Sensation seeking is a temperament associated with willingness to take risks to obtain arousal. We investigated the relationship between the polymorphisms of the COMT Val158Met and BDNF Val66Met and sensation seeking traits. The Sensation Seeking Scale (SSS) and genotyping were performed in 277 Korean healthy volunteers (165 males, 112 females). Multivariate analysis of covariance was used to test the association between the COMT and BDNF functional polymorphisms and dimensions of sensation seeking, namely, disinhibition, boredom susceptibility, experience seeking and thrill/adventure seeking. No main and interaction effects of the COMT and BDNF on SSS were observed for total subjects. However, in females, a significant gene-gene interaction effect on the boredom susceptibility of SSS was shown. Among females with COMT Met present genotype (Val/Met+Met/Met), subjects with BDNF Met absent genotype (Val/Val) had significantly higher boredom susceptibility than subjects with BDNF Met. The effects of BDNF Val66Met polymorphism on boredom susceptibility of sensation seeking traits could be modulated by COMT Val158Met polymorphism in female.

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.