Aberrant cerebro-cerebellar functional connectivity and minimal self-disturbance in individuals at ultra-high risk for psychosis and with first-episode schizophrenia

BACKGROUND

In the tradition of phenomenology, minimal selfdisturbance has been suggested as a manifestation of the core pathogenesis of schizophrenia; however, the underlying neural mechanism remains unclear. Here, in line with the concept of "cognitive dysmetria," we investigated the cerebro-cerebellar default mode network (DMN) connectivity and its association with pre-reflective minimal selfdisturbance in individuals at ultra-high risk (UHR) for psychosis and patients with first-episode schizophrenia (FES).

METHODS

Thirty-three UHR individuals, 18 FES patients, and 56 healthy controls (HCs) underwent functional magnetic resonance imaging during rest at baseline. Seed-based functional connectivity (FC) analysis was performed using the cerebellar DMN seeds from the bilateral Crus I, followed by between-group comparisons. Correlation analysis was conducted to examine the relationship between the cerebro-cerebellar FC and the self-reported severity of minimal self-disturbance in the UHR and FES groups, respectively.

RESULTS

FES participants showed significantly reduced cerebellar FC with the left presupplementary motor area (preSMA), right anterior prefrontal cortex (aPFC), and precuneus compared to HCs, while UHR participants showed an intermediate decrease between the other two groups, particularly in the left preSMA and right aPFC. Minimal self-disturbance, which appeared at similar levels in both UHR and FES groups, was significantly associated with cerebro-cerebellar FC, although each group presented different patterns of associations.

CONCLUSIONS

Aberrant cerebro-cerebellar FC, which may be closely related to minimal self-disturbance, may be able to provide meaningful insights into the real gestalt of schizophrenia and contribute to further research to predict future psychosis in UHR individuals.

Oxytocin receptor gene variants are associated with emotion recognition and resilience, but not with false-belief reasoning performance in healthy young Korean volunteers

AIMS

A growing body of literature has indicated that oxytocin is associated with several domains of social cognition and behavior. Nevertheless, the effects of oxytocin receptor gene (OXTR) polymorphisms on social phenotypes remain unclear. Therefore, we aimed to explore the genetic influence of OXTR variants on social cognition (social perception and theory of mind) and resilience in healthy individuals.

METHODS

We examined the influence of 10 common OXTR variants on social cognitive abilities, including facial emotion recognition and theory of mind, and trait resilience in 264 unrelated, healthy participants.

RESULTS

We found a significant association between the A-C haplotype at rs237887-rs2268490 and facial affect recognition. In addition, the single marker rs2254298 was significantly associated with participants' scores on the Connor-Davidson Resilience Scale. In contrast, variations in OXTR did not affect participants' performance on the false-belief reasoning task.

CONCLUSIONS

Single makers or haplotypes at OXTR may contribute to individual differences in facial emotion recognition and psychological resilience.

Aberrant Tendency of Noncurrent Emotional Experiences in Individuals at Ultra-High Risk for Psychosis

OBJECTIVE

This study aimed to investigate whether aberrant tendency of noncurrent emotion was present in individuals at ultra-high risk (UHR) for psychosis and to explore its associations with various clinical profiles.

METHODS

Fifty-seven individuals at UHR and 49 normal controls were enrolled. The tendency of experiencing noncurrent emotion was assessed using various noncurrent emotional self-reported formats, including trait [Neuroticism and Extraversion of the Eysenck Personality Questionnaire], hypothetical (Chapman's Revised Physical and Social Anhedonia Scales), and retrospective [AnhedoniaAsociality Subscale of the Scale for the Assessment of Negative Symptoms (SANS)] measures. Self-related beliefs (Self-Perception Scale), clinical positive and negative symptoms (SA Positive Symptoms and SANS), psychosocial function (Global Functioning Scale: Role Function and Global Functioning Scale: Social Function) were also examined.

RESULTS

Subjects at UHR for psychosis reported more trait unpleasant and less trait pleasant emotions, more hypothetical physical and social anhedonia, and more retrospective anhedonia than normal controls. In UHR, self-perception was correlated to trait unpleasant emotion and hypothetical physical and social anhedonia. Negative symptoms in UHR were associated with hypothetical physical anhedonia and retrospective anhedonia. Global social functioning was related to trait pleasant emotion, hypothetical physical and social anhedonia, and retrospective anhedonia. Neurocognitive function, positive symptoms, and global role functioning were not related with any noncurrent emotional experience measures in UHR.

CONCLUSION

These findings suggest that the aberrant tendency of noncurrent emotional experience may be present at the 'putative' prodromal phase and are grossly associated with self-related beliefs and psychosocial functioning but not neurocognitive functioning.

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.

Fragile Self and Malevolent Others: Biased Attribution Styles in Individuals at Ultra-High Risk for Psychosis

OBJECTIVE

Biased attribution styles of assigning hostile intention to innocent others and placing the blame were found in schizophrenia. Attribution styles in individuals at ultra-high risk (UHR) for psychosis, however, have been less studied especially for its association with various psychological factors. We investigated whether UHR individuals show increased hostility perception and blaming bias and explored the associations of these biased styles of attribution with the factor structure of multifaceted self-related psychological variables and neurocognitive performances.

METHODS

Fifty-four UHR individuals and 80 healthy controls were assessed by evaluating resilience, self-perception, self-esteem, and aberrant subjective experiences of schizotypy (physical anhedonia, social anhedonia, magical ideation, and perceptual aberration), basic symptoms, and carrying out a comprehensive neurocognitive test battery. Attribution styles were assessed using the Ambiguous Intentions Hostility Questionnaire.

RESULTS

UHR individuals, compared with normal controls, showed increased hostility perception and blaming bias. Factor analysis of self-related psychological variables and neurocognitive performances in the entire subject population showed a three-factor solution, which was designated as reflective self, pre-reflective self, and neurocognition. Multiple regression analysis in UHR individuals revealed that hostility perception bias was associated with reflective self and composite blame bias was associated with reflective and pre-reflective self.

CONCLUSION

This study supports the emergence of attribution biases in the putative 'prodromal' phase of schizophrenia. The associations of biased attribution styles with multifaceted self-related psychological constructs suggest that psychosocial interventions for biased attribution styles in UHR individuals should focus not only on reflective self but also pre-reflective self-related psychological constructs.

Coping styles in individuals at ultra-high risk for psychosis: Associations with cognitive appraisals

Maladaptive coping may play an important role in the manifestation of symptoms, functioning, and overt psychosis onset in individuals at ultra-high risk (UHR) for psychosis. To determine the factors associated with coping strategies, the relationships between cognitive appraisals and coping styles were investigated in UHR individuals. Sixty-five UHR individuals and 83 healthy controls were assessed for coping styles and cognitive appraisals of attribution bias as a primary appraisal and self-efficacy and perceived social support as a secondary appraisal. UHR participants relied more on a passive, tension-reduction coping style and less on an active, problem-focused coping style. These maladaptive coping styles in UHR individuals were significantly associated with their cognitive appraisals of stress. Aberrant attribution style of hostility perception and composite blaming bias were associated with problem-focused coping and tension-reduction, respectively. Perceived social support was related to problem-focused coping, seeking social support, and wishful thinking. General self-efficacy was associated with problem-focused coping. Our findings suggest that cognitive appraisals themselves may be the major determinants of coping styles in UHR individuals. The identified attribution styles, perceived social support, and self-efficacy may provide some clues regarding specialized interventions for the buildup of adaptive coping strategies in UHR individuals.

Cognitive Behavioral Therapy for Insomnia Reduces Hypnotic Prescriptions

OBJECTIVE

This study determined whether cognitive behavioral therapy for insomnia (CBT-i) decreased the need for sleep medications and produced better treatment outcomes than pharmacotherapy alone.

METHODS

We reviewed data from patients with insomnia in the outpatient clinic of a general hospital between 2009 and 2015. We compared 41 patients who received five sessions of CBT-i with 100 age- and sex-matched patients who received pharmacotherapy only. We evaluated the change in prescription for sleep (i.e., antidepressants, hypnotics, and others) between the first and last visits using repeated measures analysis of variance (ANOVA). Clinical global impressions and completion status at the last visit were assessed using the chisquare test.

RESULTS

We found a significant decrease in the prescription rate and the dosage of hypnotics among patients who received CBT-i when compared with control patients. There was no significant change in the dosage of antidepressants between the two groups. Achievement of case closure was better in the CBT-i group at the trend level. Clinical global impression at the last visit was not significantly different.

CONCLUSION

These results show that CBT-i reduces the need for hypnotics among insomnia patients. Our results indicate that CBT-i offers additional benefits beyond improving sleep characteristics and thus provides another reason for recommending CBT-i as a first-line treatment for insomnia.

Impaired Social and Role Function in Ultra-High Risk for Psychosis and First-Episode Schizophrenia: Its Relations with Negative Symptoms

OBJECTIVE

Psychosocial dysfunction was a nettlesome problem of schizophrenia even in their prodromal phase as well as in their first-episode. In addition, its relations with psychopathology were not determined. The aim of the present study was to examine whether the social and role function impairment was found in ultra-high risk for psychosis (UHR) individuals as well as first-episode schizophrenia patients and to explore its relations with psychopathology.

METHODS

Thirty-seven normal controls, 63 UHR participants and 28 young, first-episode schizophrenia patients were recruited. Psychosocial functioning was examined by using Global function: Social and Role scale. Psychopathologies of positive, negative and depressive symptom were also measured.

RESULTS

Social and role functioning in UHR were compromised at the equivalent level of those of first-episode schizophrenia patients. Multiple linear regression analysis revealed that social and role dysfunction was associated with negative symptoms in each UHR and first-episode schizophrenia group.

CONCLUSION

These findings suggest that the significant impairment of social and role function may be appeared before the active psychosis onset at the level of extent to those of first-episode schizophrenia patients. The psychosocial intervention strategy especially targeting the negative symptoms should be developed and provided to individuals from their prepsychotic stage of schizophrenia.

Impaired Social and Role Function in Ultra-High Risk for Psychosis and First-Episode Schizophrenia: Its Relations with Negative Symptoms

OBJECTIVE

Psychosocial dysfunction was a nettlesome of schizophrenia even in their prodromal phase as well as first episode and its relations with psychopathology were not determined. The aim of the present study was to examine whether the social and role function impairment was found in ultra-high risk for psychosis (UHR) individuals as well as first-episode schizophrenia patients and to explore its relations with psychopathology.

METHODS

Thirty-seven normal controls, 63 UHR participants and 28 young, first-episode schizophrenia patients were recruited. Psychosocial functioning was examined by using Global function: Social and Role scale. Psychopathologies of positive, negative and depressive symptom were also measured.

RESULTS

Social and role functioning in UHR were compromised at the equivalent level of those of first-episode schizophrenia patients. Multiple linear regression analysis revealed that social and role dysfunction was associated with negative symptoms in each UHR and first-episode schizophrenia group.

CONCLUSION

These findings suggest that the significant impairment of social and role function may be appeared before the active psychosis onset at the level of extent to those of first-episode schizophrenia patients. The psychosocial intervention strategy especially targeting the negative symptoms should be developed and provided to individuals from their prepsychotic stage of schizophrenia.

Prevalence of Metabolic Syndrome in Patients with Schizophrenia in Korea: A Multicenter Nationwide Cross-Sectional Study

OBJECTIVE

We designed a nationwide study with limited exclusion criteria to investigate the prevalence of metabolic syndrome (MetS) in Korea and its relationship with antipsychotic medications.

METHODS

This multicenter, cross-sectional, and observational study included patients diagnosed with schizophrenia or schizoaffective disorder. Sixteen hospitals enrolled 845 patients aged 18 to 65 years prescribed any antipsychotic medication between August 2011 and August 2013. MetS was diagnosed using the criteria of the modified Adult Treatment Panel III of the National Cholesterol Education Program with the Korean abdominal obesity definition (waist circumference ≥85 cm in women, ≥90 cm in men).

RESULTS

The prevalence of MetS in all patients was 36.5% and was significantly higher in men than women (men, 40.8%; women, 32.2%) and was significantly correlated with age [odds ratio (OR) 1.02] and duration of illness (OR 1.03). The prevalence of MetS across antipsychotic drugs in the major monotherapy group was as follows: 18.8% for quetiapine, 22.0% for aripiprazole, 33.3% for both amisulpride and paliperidone, 34.0% for olanzapine, 35% for risperidone, 39.4% for haloperidol, and 44.7% for clozapine.

CONCLUSION

The prevalence of MetS is very high in patients with schizophrenia or schizoaffective disorder. Screening and monitoring of MetS is also strongly recommended.

Associations between actigraphy-assessed sleep, inflammatory markers, and insulin resistance in the Midlife Development in the United States (MIDUS) study

BACKGROUND

Disturbed sleep has been associated with increased insulin resistance and elevated inflammation. Although there is growing body of evidence that activation of inflammatory pathways plays a crucial role in the development of insulin resistance, the mediational model whereby sleep disturbances influence inflammation that drives insulin resistance has not been fully assessed in general population studies with objectively measured sleep. This study aimed to examine associations between objectively measured sleep, inflammatory markers, and insulin resistance simultaneously and in a mediational analysis, thereby offering insights into the possible causal model.

METHODS

Cross-sectional data collected from 2004 to 2009 during the Midlife Development in the United States II biomarker project were used. The study population included 374 community-based participants (138 men and 236 women) who completed seven nights of wrist actigraphy. Multiple regressions controlling for age and statistically significant variables in univariate regressions were performed to evaluate the associations between actigraphy-assessed sleep measures, inflammatory cytokines, and insulin resistance.

RESULTS

The regression models showed that in women, higher sleep onset latency (SOL) was associated with higher insulin resistance after controlling for age, smoking, obesity, diabetes, depression, and inflammatory cytokines. Higher SOL was also associated with higher interleukin (IL)-6 and C-reactive protein (CRP) levels in women, but no association was found in men. Using mediation models in women, the association between SOL and insulin resistance was partially explained by the indirect effect of inflammatory cytokines.

CONCLUSION

A combination of inflammation and other unidentified pathways may contribute to the relationship between disturbed sleep and glucose homeostasis.

Common variants of HTR3 genes are associated with obsessive-compulsive disorder and its phenotypic expression

Evidence from literature supports the existence of associations between serotonin-related genetic variants and obsessive-compulsive disorder (OCD), but few studies have explored the involvement of serotonin receptor type 3 genes (HTR3) in OCD. To identify whether HTR3 variability affects an individual’s susceptibility to OCD, we examined 10 HTR3 variants in 596 individuals with OCD and 599 controls. A significant difference existed in the genotypic distribution of the HTR3B variant rs1176744 between individuals with OCD and controls (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.60–0.91, P = 0.0043). A protective haplotype in HTR3B was also associated with OCD (OR = 0.77, CI = 0.63–0.95, permutated P = 0.0179). Analyses of OCD sub-phenotypes demonstrated significant associations between rs3758987 and early onset OCD in male subjects (OR = 0.49, CI = 0.31–0.79, P = 0.0031) and among rs6766410, rs6443930, and the cleaning dimension in female subjects (OR = 0.36, CI = 0.18–0.69, P = 0.0016 and OR = 0.47, CI = 0.29–0.79, P = 0.0030, respectively). Additionally, rs6766410 was related to contamination-based disgust in OCD (P = 0.0044). These results support that common HTR3 variants are involved in OCD and some of its clinical phenotypes.

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.

Heterogeneity of Psychosis Risk Within Individuals at Clinical High Risk: A Meta-analytical Stratification

IMPORTANCE

Individuals can be classified as being at clinical high risk (CHR) for psychosis if they meet at least one of the ultra-high-risk (UHR) inclusion criteria (brief limited intermittent psychotic symptoms [BLIPS] and/or attenuated psychotic symptoms [APS] and/or genetic risk and deterioration syndrome [GRD]) and/or basic symptoms [BS]. The meta-analytical risk of psychosis of these different subgroups is still unknown.

OBJECTIVE

To compare the risk of psychosis in CHR individuals who met at least one of the major inclusion criteria and in individuals not at CHR for psychosis (CHR-).

DATA SOURCES

Electronic databases (Web of Science, MEDLINE, Scopus) were searched until June 18, 2015, along with investigation of citations of previous publications and a manual search of the reference lists of retrieved articles.

STUDY SELECTION

We included original follow-up studies of CHR individuals who reported the risk of psychosis classified according to the presence of any BLIPS, APS and GRD, APS alone, GRD alone, BS, and CHR-.

DATA EXTRACTION AND SYNTHESIS

Independent extraction by multiple observers and random-effects meta-analysis of proportions. Moderators were tested with meta-regression analyses (Bonferroni corrected). Heterogeneity was assessed with the I2 index. Sensitivity analyses tested robustness of results. Publication biases were assessed with funnel plots and the Egger test.

MAIN OUTCOMES AND MEASURES

The proportion of each subgroup with any psychotic disorder at 6, 12, 24, 36, and 48 or more months of follow-up.

RESULTS

Thirty-three independent studies comprising up to 4227 individuals were included. The meta-analytical proportion of individuals meeting each UHR subgroup at intake was: 0.85 APS (95%CI, 0.79-0.90), 0.1 BLIPS (95%CI, 0.06-0.14), and 0.05 GRD (95%CI, 0.03-0.07). There were no significant differences in psychosis risk at any time point between the APS and GRD and the APS-alone subgroups. There was a higher risk of psychosis in the any BLIPS greater than APS greater than GRD-alone subgroups at 24, 36, and 48 or more months of follow-up. There was no evidence that the GRD subgroup has a higher risk of psychosis than the CHR- subgroup. There were too few BS or BS and UHR studies to allow robust conclusions.

CONCLUSIONS AND RELEVANCE

There is meta-analytical evidence that BLIPS represents separate risk subgroup compared with the APS. The GRD subgroup is infrequent and not associated with an increased risk of psychosis. Future studies are advised to stratify their findings across these different subgroups. The CHR guidelines should be updated to reflect these differences.

Impaired facial emotion recognition in individuals at ultra-high risk for psychosis and with first-episode schizophrenia, and their associations with neurocognitive deficits and self-reported schizotypy

OBJECTIVE

This study aims to quantify facial emotion recognition abnormalities and their relation to neurocognitive dysfunction and schizotypy in individuals at ultra-high risk (UHR) for psychosis and patients with first-episode schizophrenia (FES).

METHODS

Forty individuals at UHR for psychosis, 24 patients with FES and 46 normal controls performed a facial emotion recognition task that presented facial photographs encompassing all basic emotions. The perceptual aberration scale and revised social anhedonia scale were employed for self-reported assessment of schizotypy. An intellectual functioning (IQ) test and a broad battery of neurocognitive tests were conducted. Emotional task performance indexed by accuracy rate of specific emotion was compared among three groups. The correlation of accuracy rate with neurocognitive tests and schizotypy scales were analyzed within each clinical group.

RESULTS

A recognition deficit of facial emotions was present in both clinical groups, even after adjusting for IQ and gender as covariates. This emotional deficit showed few significant relationships with broad range of individual neurocognitive measures. Meanwhile, this deficit demonstrated significant relationships with schizotypy, especially perceptual aberration in each clinical group.

CONCLUSIONS

Facial emotion recognition deficit may not only be present in FES patients, but may already have evolved prior to the onset of overt psychotic symptoms. This emotion recognition deficit may be linked to a perceptual aberration and largely independent of broad range of neurocognitive dysfunction.

Neurocognitive impairments in individuals at ultra-high risk for psychosis: Who will really convert?

OBJECTIVE

Impairments in neurocognitive function are considered as core features of schizophrenia. Individuals at ultra-high risk (UHR) for psychosis, the 'putative' prodrome of schizophrenia, generally show levels of impairments intermediate between schizophrenia patients and healthy controls. We investigated the neurocognitive performance of individuals at UHR for psychosis, comparing them with patients with first-episode schizophrenia (FES) and healthy controls (HC), and explored the predictivity of baseline neurocognitive function in the UHR group for transition to overt psychosis.

METHOD

Individuals at UHR for psychosis (n = 60), patients with FES (n = 39), and HC subjects (n = 94) participated in the present study. All participants performed a comprehensive neurocognitive battery, consisting of tests for five separate neurocognitive domains (executive function, attention/working memory, processing speed, verbal memory, and spatial memory). UHR subjects were assessed for transition every month during 24 months of follow-up.

RESULTS

Neurocognitive performance in the UHR group was largely at intermediate levels. Attention/working memory and verbal memory were significantly different from both the FES and HC groups. In the UHR group, processing speed was decreased to the level of the FES group, while executive function and spatial memory were relatively preserved. In the Cox regression model, spatial memory significantly predicted the transition to overt psychosis in the UHR group.

CONCLUSIONS

The present study showed that neurocognitive impairments were evident in UHR individuals prior to the onset of overt psychosis. Our findings generally support the neurodevelopmental model of schizophrenia and suggest that there could be different developmental trajectories between converters and non-converters.

Relationships between chronotypes and affective temperaments in healthy young adults

BACKGROUND

Chronotype, an individual׳s preferred time for activity and sleep, has been known to be associated with affective disorders. Affective temperaments may be subclinical manifestations that represent a biological diathesis for affective disorders. Therefore, the aim of this study is to investigate the relationships between circadian preferences and affective temperaments.

METHODS

Six hundred and forty one healthy young adults (376 male, 265 female) completed the Korean Translation of Composite Scale of Morningness to measure diurnal preferences and the Temperament Scale of Memphis, Pisa, Paris and San Diego - Autoquestionnaire (TEMPS-A) to measure cyclothymic, depressive, hyperthymic, irritable, and anxious affective temperaments. Multivariate analyses of covariance were computed with the five affective temperaments as dependent variables, chronotype and gender as an independent variable, and age as a covariate.

RESULTS

One hundred and sixteen subjects were classified as having morning-type (18.1%), 402 as intermediate-type (62.7%), and 123 as evening-type (19.2%) circadian preferences. Evening-type was significantly associated with greater depressive, cyclothymic, irritable, and anxious temperaments, while morning-type was significantly associated with hyperthymic temperament.

LIMITATIONS

The present study only used self-report questionnaires to measure diurnal preference.

CONCLUSIONS

Evening-type subjects were more likely to have depressive, cyclothymic, irritable and anxious temperaments, whereas morning-types were more likely to have hyperthymic temperament. This relationship between chronotype and affective temperament might be important for vulnerability to affective disorders.

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.

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.

Reduced binding potential of GABA-A/benzodiazepine receptors in individuals at ultra-high risk for psychosis: an [18F]-fluoroflumazenil positron emission tomography study

BACKGROUND

Altered transmission of gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter, may contribute to the development of schizophrenia. The purpose of the present study was to investigate the presence of GABA-A/benzodiazepine (BZ) receptor binding abnormalities in individuals at ultra-high risk (UHR) for psychosis in comparison with normal controls using [(18)F]-fluoroflumazenil (FFMZ) positron emission tomography (PET). In particular, we set regions of interest in the striatum (caudate, putamen, and nucleus accumbens) and medial temporal area (hippocampus and parahippocampal gyrus).

METHODS

Eleven BZ-naive people at UHR and 15 normal controls underwent PET scanning using [(18)F]-FFMZ to measure GABA-A/BZ receptor binding potential. The regional group differences between UHR individuals and normal controls were analyzed using Statistical Parametric Mapping 8 software. Participants were evaluated using the structured interview for prodromal syndromes and neurocognitive function tasks.

RESULTS

People at UHR demonstrated significantly reduced binding potential of GABA-A/BZ receptors in the right caudate.

CONCLUSIONS

Altered GABAergic transmission and/or the imbalance of inhibitory and excitatory systems in the striatum may be present at the putative prodromal stage and play a pivotal role in the pathophysiology of psychosis.

Theory of mind as a mediator of reasoning and facial emotion recognition: findings from 200 healthy people

OBJECTIVE

It was proposed that the ability to recognize facial emotions is closely related to complex neurocognitive processes and/or skills related to theory of mind (ToM). This study examines whether ToM skills mediate the relationship between higher neurocognitive functions, such as reasoning ability, and facial emotion recognition.

METHODS

A total of 200 healthy subjects (101 males, 99 females) were recruited. Facial emotion recognition was measured through the use of 64 facial emotional stimuli that were selected from photographs from the Korean Facial Expressions of Emotion (KOFEE). Participants were requested to complete the Theory of Mind Picture Stories task and Standard Progressive Matrices (SPM).

RESULTS

Multiple regression analysis showed that the SPM score (t=3.19, p=0.002, β=0.22) and the overall ToM score (t=2.56, p=0.011, β=0.18) were primarily associated with a total hit rate (%) of the emotion recognition task. Hierarchical regression analysis through a three-step mediation model showed that ToM may partially mediate the relationship between SPM and performance on facial emotion recognition.

CONCLUSION

These findings imply that higher neurocognitive functioning, inclusive of reasoning, may not only directly contribute towards facial emotion recognition but also influence ToM, which in turn, influences facial emotion recognition. These findings are particularly true for healthy young people.