Fat loss and muscle gain: The possible role of cortical glutamate in determining the efficacy of physical exercise

BACKGROUND

Physical exercise is widely acknowledged for its health benefits, but its effectiveness in treating obesity remains contentious due to variability in response. Owing to the roles of glutamate in appetite regulation, food addiction, and impulsivity, this observational cohort-study evaluated medial prefrontal cortex (mPFC) glutamate as a predictor of variability in exercise response, specifically in terms of fat loss and muscle gain.

METHODS

Healthy non-exercising adult men (n = 21) underwent an 8-week supervised exercise program. Baseline glutamate levels in the mPFC were measured through magnetic resonance spectroscopy. For exercise-dependent changes in body composition (fat and muscle mass), basal metabolic rate (BMR), and blood metabolic biomarkers related to lipid and glucose metabolism, measurements were obtained through bioelectrical impedance and blood sample analyses, respectively.

RESULTS

The exercise program resulted in significant improvements in body composition, including reductions in percentage body fat mass, body fat mass, and waist-to-hip ratio and an increase in mean muscle mass. Furthermore, BMR and metabolic indicators linked to glucose and lipids exhibited significant changes. Notably, lower baseline glutamate levels were associated with greater loss in percentage body fat mass (r = 0.482, p = 0.027), body fat mass (r = 0.441, p = 0.045), and increase in muscle mass (r = -0.409, p = 0.066, marginal) following the exercise program.

CONCLUSION

These preliminary findings contribute to our understanding of the neurobiology of obesity and emphasize the significance of glutamate in regulating body composition. The results also highlight cortical glutamate as a potential predictor of exercise-induced fat loss and muscle gain.

Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients

BACKGROUND

Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs).

METHODS

We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy.

RESULTS

Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for.

CONCLUSIONS

We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

Machine learning for prediction of schizophrenia based on identifying the primary and interaction effects of minor physical anomalies

In the neurodevelopmental model of schizophrenia, minor physical anomalies (MPAs) are considered neurodevelopmental markers of schizophrenia. To date, there has been no research to evaluate the interaction between MPAs. Our study built and used a machine learning model to predict the risk of schizophrenia based on measurements of MPA items and to investigate the potential primary and interaction effects of MPAs. The study included 470 patients with schizophrenia and 354 healthy controls. The models used are classical statistical model, Logistic Regression (LR), and machine leaning models, Decision Tree (DT) and Random Forest (RF). We also plotted two-dimensional scatter diagrams and three-dimensional linear/quadratic discriminant analysis (LDA/QDA) graphs for comparison with the DT dendritic structure. We found that RF had the highest predictive power for schizophrenia (Full-training AUC = 0.97 and 5-fold cross-validation AUC = 0.75). We identified several primary MPAs, such as the mouth region, high palate, furrowed tongue, skull height and mouth width. Quantitative MPA analysis indicated that the higher skull height and the narrower mouth width, the higher the risk of schizophrenia. In the interaction, we further identified that skull height and mouth width, furrowed tongue and skull height, high palate and skull height, and high palate and furrowed tongue, showed significant two-item interactions with schizophrenia. A weak three-item interaction was found between high palate, skull height, and mouth width. In conclusion, we found that the two machine learning methods showed good predictive ability in assessing the risk of schizophrenia using the primary and interaction effects of MPAs.

The Association between Default-mode Network Functional Connectivity and Childhood Trauma on the Symptom Load in Male Adults with Methamphetamine Use Disorder

Objective

: The relationship between adverse childhood experiences and methamphetamine use disorder (MUD) has been shown in previous studies; nevertheless, the underlying neural mechanisms remain elusive. Childhood trauma is associated with aberrant functional connectivity (FC) within the default-mode network (DMN). Furthermore, within the DMN, FC may contribute to impaired self-awareness in addiction, while cross-network FC is critical for relapse. We aimed to investigate whether childhood trauma was associated with DMN-related resting-state FC among healthy controls and patients with MUD and to examine whether DMN-related FC affected the effect of childhood trauma on the symptom load of MUD diagnosis.

Methods

: Twenty-seven male patients with MUD and 27 male healthy controls were enrolled and completed the Childhood Trauma Questionnaire. DMN-related resting-state FC was examined using functional magnetic resonance imaging.

Results

: There were 47.1% healthy controls and 66.7% MUD patients in this study with adverse childhood experiences. Negative correlations between adverse childhood experiences and within-DMN FC were observed in both healthy controls and MUD patients, while within-DMN FC was significantly altered in MUD patients. The detrimental effects of adverse childhood experiences on MUD patients may be attenuated through DMN-executive control networks (ECN) FC.

Conclusion

: Adverse childhood experiences were negatively associated with within-DMN FC in MUD patients and healthy controls. However, DMN-ECN FC may attenuate the effects of childhood trauma on symptoms load of MUD.

The relationship between peripheral insulin resistance and social cognitive deficits among euthymic patients with bipolar disorder

BACKGROUND

Despite extensive literature documenting emotion-related social-cognitive deficits in euthymic patients with bipolar disorder (BD), the factors contributing to these deficits have not been definitively established. To address this gap, the present study aimed to examine the association between peripheral insulin resistance (IR) and emotion-related social-cognitive abilities in BD patients and controls.

METHOD

Sixty-five BD patients and 38 non-psychiatric controls were recruited, and their social cognitive ability and IR were measured using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and the homeostasis model assessment of insulin resistance (HOMA-IR), respectively.

RESULTS

The study found that the BD patients scored significantly lower than the non-psychiatric controls in the task of emotional management. The BD patients had a higher mean HOMA-IR value as compared with the controls but this result was not statistically significant (p = 0.051). The interaction between BD diagnosis and HOMA-IR value was significant on the MSCEIT Facilitating emotions branch and Facilitation subscale (p = 0.024, p = 0.010), and post-hoc analyses revealed that the BD patients in the higher HOMA-IR group had significantly lower scores than BD patients in the lower HOMA-IR group and the non-psychiatric controls in the higher HOMA-IR group on both the MSCEIT Facilitating emotion branch and Facilitation subscale.

LIMITATIONS

Due to the cross-sectional nature of the study, causality could not be inferred. The study did not examine potential mediators or moderators between IR and social cognition.

CONCLUSIONS

The results suggested that BD patients with IR experience additional impairment in specific domains of social cognition.

Are the sensorimotor control capabilities of the hands the factors influencing hand function in people with schizophrenia?

BACKGROUND

Previous works reported people with schizophrenia experienced inferior hand functions which influence their daily participation and work efficiency. Sensorimotor capability is one of indispensable elements acting in a well-executed feed-forward and feedback control loop to contribute to hand performances. However, rare studies investigated contribution of sensorimotor ability to hand functions for people with schizophrenia. This study aimed to explore hand function in people with schizophrenia based on the perspective of the sensorimotor control capabilities of the hands.

METHODS

Twenty-seven people at the chronic stage of schizophrenia were enrolled. The following assessment tools were used: the Purdue Pegboard Test (PPT) and the VALPAR Component Work Sample-8 (VCWS 8) system for hand function; the Self-Reported Graphic version of the Personal and Social Performance (SRG-PSP) scale for functionality; and the Semmes-Weinstein Monofilaments (SWM), the pinch-holding-up-activity (PHUA) test and the Manual Tactile Test (MTT) for the sensory and sensorimotor parameters. The Clinical Global Impression-Severity (CGI-S) scale and the Extrapyramidal Symptom Rating Scale (ESRS) were used to grade the severity of the illness and the side-effects of the drugs. Spearman's rank correlation coefficient was used to analyze associations among hand function, functionality, and sensorimotor capabilities. A multiple linear regression analysis was used to identify the determinants of hand function.

RESULTS

The results indicated that both hand function and sensorimotor capability were worse in people with schizophrenia than in healthy people, with the exception of the sensory threshold measured with the SWM. Moreover, the sensorimotor abilities of the hands were associated with hand function. The results of the regression analysis showed that the MTT measure of stereognosis was a determinant of the PPT measure of the dominant hand function and of the performance on the VCWS 8, and that the ESRS and the MTT measure of barognosis were determinants of the performance on the assembly task of the PPT.

CONCLUSIONS

The findings suggested that sensorimotor capabilities, especially stereognosis and barognosis, are crucial determinants of hand function in people with schizophrenia. The results also revealed that the side effects of drugs and the duration of the illness directly affect hand function.

CLINICAL TRAIL REGISTRATION

ClinicalTrials.gov , identifier NCT04941677, 28/06/2021.

Mentalizing in a movie for the assessment of social cognition (MASC): the validation in a taiwanese sample

BACKGROUND

The present study evaluated the psychometrics properties of a sensitive video-based test used in the evaluation of mentalizing skills, that is, the Movie for the Assessment of Social Cognition-Taiwanese version (MASC-TW).

METHODS

We recruited two independent samples of nonclinical participants (N = 167) and adult patients with schizophrenia (N = 41). The MASC-TW and two other social cognition measures, namely the Chinese version of Theory of Mind task (ToM) and the Taiwanese version of the Diagnostic Analysis of Nonverbal Accuracy-2 (DANAV-TW-2), and an executive function measure of the Wisconsin Card Sorting Test (WCST), were administered to both groups.

RESULTS

The MASC proved to be a reliable measure of mentalizing capacity, high Cronbach's α value of 0.87. The intraclass correlation coefficient for the MASC-TW total correct scores was 0.85 across three waves of data collection. Across the entire sample, the scores on the MASC-TW were significantly correlated with verbal and nonverbal scores for the ToM task and recognition of facial and prosodic emotion on the DANAV-TW-2. Both executive function and emotion recognition emerged as noteworthy predictors of mentalizing, indicating that these two variables might play crucial roles in the development of mentalizing capacities. Finally, a receiver operating characteristic analysis revealed that in patients with schizophrenia, the MASC was the most accurate discriminator of diagnostic groups, highlighting the validity of the MASC.

CONCLUSIONS

Overall, the MASC-TW is an ecologically valid and useful tool for assessing mentalizing abilities in a Taiwanese population.

Social cognitive deficit is associated with visuomotor coordination impairment and dopamine transporter availability in euthymic bipolar disorder

BACKGROUND

Extensive evidence has suggested functional connections between co-occurring visuomotor and social cognitive deficits in neuropsychiatric disorders; however, such association has not been studied in bipolar disorder (BD). We aimed to investigate the relationship between visuomotor coordination and social cognition in the euthymic stage of BD (euBD). Given the shared neurobiological underpinnings involving the dopaminergic system and corticostriatal circuitry, we hypothesized a positive correlation between social cognition and visuomotor coordination in euBD patients.

METHODS

40 euBD patients and 59 healthy control (HC) participants underwent evaluation of social (Diagnostic Analysis of Nonverbal Accuracy 2-Taiwan version (DANVA-2-TW)), non-social cognitive function and visuomotor coordination. A subgroup of participants completed single-photon emission computed tomography for striatal dopamine transporter (DAT) availability assessment.

RESULTS

EuBD patients showed impaired nonverbal emotion recognition (ps ≤ 0.033) and poorer visuomotor coordination (ps < 0.003) compared to HC, with a positive correlation between these two abilities (r = 0.55, p < 0.01). However, after considering potential confounding factors, instead of visuomotor coordination, striatal DAT availability was a unique predictor of emotion recognition accuracy in euBD (beta = 0.33, p = 0.001).

CONCLUSION

Our study result supported a functional association between social cognition and visuomotor coordination in euBD, with striatal dopaminergic dysfunction emerged as a crucial contributing factor in their interrelation.

Altered glutamate level and its association with working memory among patients with treatment-resistant schizophrenia (TRS): a proton magnetic resonance spectroscopy study

BACKGROUND

Treatment-resistant schizophrenia (TRS) and non-TRS may be associated with different dopaminergic and glutamatergic regulations. The concept of dysregulated glutamatergic concentrations in specific brain regions remains controversial. Herein, we aimed to assess (i) the distribution of the glutamatergic concentration in the brain, (ii) the association between working memory (WM) differences in TRS and non-TRS patients, and (iii) whether an alteration in the glutamate (Glu) level is associated with WM.

METHODS

The participants included 38 TRS patients, 35 non-TRS patients, and 19 healthy controls (HCs), all of whom underwent 1.5-Tesla proton magnetic resonance spectroscopy of anterior cingulate cortex (ACC) and medial prefrontal cortex (MPFC). The ratios of glutamatergic neurometabolites to N-acetylaspartate + N-acetyl aspartylglutamate (NAAx) were calculated. Cognitive function was assessed using the Wechsler Adult Intelligence Scales, 4th Edition, which included the working memory index (WMI).

RESULT

The TRS patients had a higher glutamate + glutamine (Glx)/NAAx ratio compared to the non-TRS patients and HCs in the ACC, but this was not significantly different in the MPFC. WM was negatively correlated with Glx/NAAx in the ACC among the non-TRS patients, but not in the TRS patients or HCs.

CONCLUSIONS

Our findings were consistent with most studies indicating that the glutamatergic concentration in the ACC plays important roles in the classification of TRS and cognition. Our results may provide potential evidence for predictors and treatment response biomarkers in TRS patients. Further research is needed to probe the value using the relationship between Glu and WM as a potential prognostic predictor of schizophrenia.

Disrupted white matter network of brain structural connectomes in bipolar disorder patients revealed by q-ball imaging

BACKGROUND

Structural and functional brain changes have been found to be associated with altered emotion and cognition in patients with bipolar disorder (BD). Widespread microstructural white matter abnormalities have been observed using traditional structural imaging in BD. q-Ball imaging (QBI) and graph theoretical analysis (GTA) improve the specificity and sensitivity and high accuracy of fiber tracking. We applied QBI and GTA to investigate and compare the structural connectivity alterations and network alterations in patients with and without BD.

METHODS

Sixty-two patients with BD and 62 healthy controls (HCs) completed a MR scan. We evaluated the group differences in generalized fractional anisotropy (GFA) and normalized quantitative anisotropy (NQA) values by voxel-based statistical analysis with QBI. We also evaluated the group differences in topological parameters of GTA and subnetwork interconnections in network-based statistical analysis (NBS).

RESULTS

The QBI indices in the BD group were significantly lower than those in the HC group in the corpus callosum, cingulate gyrus, and caudate. The GTA indices indicated that the BD group demonstrated less global integration and higher local segregation than the HC group, but they retained small-world properties. NBS evaluation showed that the majority of the more connected subnetworks in BD occurred in thalamo-temporal/parietal connectivity.

CONCLUSION

Our findings supported white matter integrity with network alterations in BD.

DNA methylation signature aberration as potential biomarkers in treatment-resistant schizophrenia: Constructing a methylation risk score using a machine learning method

Treatment-resistant schizophrenia (TRS) is defined as a non-response to at least two trials of antipsychotic medication with an adequate dose and duration. We aimed to evaluate the discriminant abilities of DNA methylation probes and methylation risk score between treatment-resistant schizophrenia and non-treatment-resistant schizophrenia. This study recruited 96 schizophrenia patients (TRS and non-TRS) and 56 healthy controls (HC). Participants were divided into a discovery set and a validation set. In the discovery set, we conducted genome-wide methylation analysis (human MethylationEPIC 850K BeadChip) on the subject's blood DNA and discriminated significant methylation signatures, then verified these methylation signatures in the validation set. Based on genome-wide scans of TRS versus non-TRS, thirteen differentially methylated probes were identified at FDR <0.05 and >20% differences in DNA methylation β-values. Next, we selected six probes within gene coding regions (LOC404266, LOXL2, CERK, CHMP7, and SLC17A9) to conduct verification in the validation set using quantitative methylation-specific PCR (qMSP). These six methylation probes showed satisfactory discrimination between TRS patients and non-TRS patients, with an AUC ranging from 0.83 to 0.92, accuracy ranging from 77.8% to 87.3%, sensitivity ranging from 80% to 90%, and specificity ranging from 65.6% to 85%. This methylation risk score model showed satisfactory discrimination between TRS patients and non-TRS patients, with an accuracy of 88.3%. These findings support that methylation signatures may be used as an indicator of TRS vulnerability and provide a model for the clinical use of methylation to identify TRS.

Development and validation of a web-based prediction tool on minor physical anomalies for schizophrenia

In support of the neurodevelopmental model of schizophrenia, minor physical anomalies (MPAs) have been suggested as biomarkers and potential pathophysiological significance for schizophrenia. However, an integrated, clinically useful tool that used qualitative and quantitative MPAs to visualize and predict schizophrenia risk while characterizing the degree of importance of MPA items was lacking. We recruited a training set and a validation set, including 463 schizophrenia patients and 281 healthy controls to conduct logistic regression and the least absolute shrinkage and selection operator (Lasso) regression to select the best parameters of MPAs and constructed nomograms. Two nomograms were built to show the weights of these predictors. In the logistic regression model, 11 out of a total of 68 parameters were identified as the best MPA items for distinguishing between patients with schizophrenia and controls, including hair whorls, epicanthus, adherent ear lobes, high palate, furrowed tongue, hyperconvex fingernails, a large gap between first and second toes, skull height, nasal width, mouth width, and palate width. The Lasso regression model included the same variables of the logistic regression model, except for nasal width, and further included two items (interpupillary distance and soft ears) to assess the risk of schizophrenia. The results of the validation dataset verified the efficacy of the nomograms with the area under the curve 0.84 and 0.85 in the logistic regression model and lasso regression model, respectively. This study provides an easy-to-use tool based on validated risk models of schizophrenia and reflects a divergence in development between schizophrenia patients and healthy controls (https://www.szprediction.net/).

Striatal Dopamine Transporter Availability is Associated with Sleep Disturbance among Patients with Bipolar I Disorder: A Single-photon Emission Computed Tomography Study Using [99mTc] TRODAT-1

OBJECTIVE

Bipolar disorder (BD) is characterized by the poor sleep quality. Whether the striatal dopamine transporter (DAT) availability is related to sleep quality among patients with BD is unclear.

METHODS

Fifty-three euthymic patients with BD (24 BD-I and 29 BD-II) and sixty-eight healthy controls were enrolled. The Chinese Version of the Pittsburgh Sleep Quality Index (PSQI) was used, and the availability of DAT was assessed by single-photon emission computed tomography (SPECT) using [^99mTc] TRODAT-1.

RESULTS

The sleep disturbance component of the PSQI was significantly associated with the level of DAT availability among patients with BD.

CONCLUSION

The striatal dopaminergic activity that contributes to resilience to adversity was associated with sleep pattern among patients with BD.

Profiling antibody signature of schizophrenia by Escherichia coli proteome microarrays

Schizophrenia (SZ) is influenced by genetic and environmental factors, and associated with chronic neuroinflammation. If the symptoms express after adolescence, environmental impacts are more substantial, and the disease is defined as adult-onset schizophrenia (AOS). Effects of environmental factors on antibody responses such as Escherichia coli (E. coli) to immunoglobulin G (IgG) and immunoglobulin M (IgM) might increase the severity of symptoms in SZ via the gut-brain axis. The purpose of this study is to reveal antibody profiles of SZ against bacterial protein antigens. We analyzed the IgG and IgM antibodies using E. coli proteome microarrays from 80 SZ patients and 40 healthy controls (HC). Using support vector machine to select panels of proteins differentiating between groups and conducted enrichment analysis for those proteins. We identified that the groL, pldA, yjjU, livG, and ftsE can classify IgGs in AOS vs HC achieved accuracy of 0.7. The protein yjjU, livG and ftsE can form the best combination panel to classify IgG in AOS vs HC with accuracy of 0.8. The enrichment results are highly related to ABC (ATP binding cassette) transporter in the protein domain and cellular component. We further found that the human ATP binding cassette subfamily b member 1 (ABCB1) autoantibody level in AOS is significantly higher than in HC. The findings suggest that AOS had different immunoglobulin production compared to early-onset schizophrenia (EOS) and HC. We also identified potential antibody biomarkers of AOS and found their antigens are enriched in ABC transporter related domains, including human ABCB1 protein.

Association Between Inflammatory Cytokines, Executive Function, and Substance Use in Patients With Opioid Use Disorder and Amphetamine-Type Stimulants Use Disorder

BACKGROUND

Long-term opioid and amphetamine-type stimulants (ATS) abuse may affect immunological function and impair executive function. We aimed to determine whether biomarkers of inflammation and executive function were associated with substance use in individuals with opioid use disorder (OUD) and ATS use disorder (ATSUD). The interactions between these biomarkers were also explored.

METHODS

We assessed plasma cytokines [tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-8, IL-6, transforming growth factor (TGF)-β1, brain-derived neurotrophic factor (BDNF), and executive function in terms of the Wisconsin Card Sorting Test (WCST) and Continuous Performance Test (CPT) in OUD and ATSUD patients and healthy controls (HC). OUD and ATSUD patients were followed for 12 weeks, and their urine morphine and amphetamine tests, cytokine levels, and executive function were repeatedly measured.

RESULTS

We enrolled 483 patients and 145 HC. Plasma TNF-α, CRP, IL-8, IL-6, and BDNF levels and most subscale scores on the WCST and CPT significantly differed between OUD and ATSUD patients and HC. Increased TNF-α levels and more perseveration error on the WCST were significantly associated with more urine drug-positive results and less abstinence. Plasma IL-6 and CRP levels were significantly negatively correlated with WCST and CPT performance.

CONCLUSION

OUD and ATSUD patients had more inflammation and worse executive function than HC. Inflammatory markers and WCST performance were associated with their urinary drug results, and higher inflammation was associated with poor executive function. Studies on regulating the inflammatory process and enhancing executive function in OUD and ATSUD are warranted.

A Longitudinal Study of the Association between the LEPR Polymorphism and Treatment Response in Patients with Bipolar Disorder

Patients with bipolar disorder (BD) exhibit individual variability in the treatment outcome, and genetic background could contribute to BD itself and the treatment outcome. Leptin levels significantly change in BD patients treated with valproate (VPA), but whether LEPR polymorphisms are associated with treatment response is still unknown. This longitudinal study aimed to investigate the associations between LEPR polymorphisms and VPA treatment response in BD patients who were drug naïve at their first diagnosis of BD. The single-nucleotide polymorphisms (SNPs) of LEPR (rs1137101, rs1137100, rs8179183, and rs12145690) were assayed, and the LEPR polymorphism frequencies of alleles and genotypes were not significantly different between the controls (n = 77) and BD patients (n = 130). In addition, after the 12-week course of VPA treatment in BD patients, the LEPR polymorphisms showed significant effects on changes in disease severity. Moreover, considering the effect of the LEPR haplotype, the frequency of the CAGG haplotype in BD patients was higher than that in the controls (9.3 vs. 2.9%, p = 0.016), and the LEPR CAGG haplotype was associated with a better treatment response than the other haplotypes in BD patients receiving VPA treatment. Therefore, LEPR polymorphisms might serve as mediators involved in the therapeutic action of VPA treatment.

Serotonin Modulates the Correlations between Obsessive-compulsive Trait and Heart Rate Variability in Normal Healthy Subjects: A SPECT Study with [123I]ADAM and Heart Rate Variability Measurement

Objective

The impact of serotonergic system on obsessive-compulsive disorder (OCD) is well studied. However, the correlation between OC presentations and autonomic nervous system (ANS) is still unclear. Furthermore, whether the correlation might be modulated by serotonin is also uncertain.

Methods

We recruited eighty-nine healthy subjects. Serotonin transporter (SERT) availability by [¹²³I]ADAM and heart rate variability (HRV) tests were measured. Symptoms checklist-90 was measured for the OC presentations. The interaction between HRV and SERT availability were calculated and the correlation between HRV and OC symptoms were analyzed after stratified SERT level into two groups, split at medium.

Results

The interactions were significant in the factors of low frequency (LF), high frequency (HF), and root mean square of successive differences (RMSSD). Furthermore, the significantly negative correlations between OC symptoms and the above HRV indexes existed only in subjects with higher SERT availability.

Conclusion

OC symptoms might be correlated with ANS regulations in subjects with higher SERT availability.

Correlation between loneliness, personality traits, and treatment outcomes in patients with methamphetamine use disorder

The aim of this study was to investigate whether loneliness and personality traits correlate with the treatment outcome of methamphetamine use disorder. In this 1-year longitudinal study, a total 106 participants (98 males, 8 females), with a mean age 36.3 ± 9.6 years were enrolled. We measured UCLA Loneliness Scale and Tridimensional Personality Questionnaire at baseline, while craving level at baseline, week 12, 24, 36, and 48. Urinary methamphetamine tests were given 17 times. For the evaluation of the data, multiple linear regression and generalized linear mixed models were used. The baseline results showed lower levels of the harm avoidance trait and higher levels of loneliness were significantly associated with higher craving levels (p=0.04 and 0.04). Moreover, loneliness was not only positively associated with craving levels (B=0.05, p<0.01) but with urinary methamphetamine positive results (B= 0.08, p=0.03) during one-year treatment. The findings suggested that loneliness was associated with poor methamphetamine treatment outcome (greater craving levels and higher proportion of positive methamphetamine urine tests) and lower harm avoidance traits are associated with higher craving levels.

Associations of emotion recognition, loneliness, and social functioning in euthymic patients with bipolar disorder

Emotion recognition deficit is related to impaired community functioning. Loneliness is also associated with impaired social performance. However, the way in which emotion recognition and loneliness may contribute to social functioning remains unclear in euthymic patients with bipolar disorder. We aimed to examine emotion recognition ability in Han Chinese euBD patients relative to healthy controls (HCs) and to investigate the associations between emotion recognition, loneliness, and social functioning. Thirty-nine HCs and 46 euthymic BD patients completed an emotion recognition task and nonsocial cognitive measures related to executive function and attention. The UCLA loneliness scale and Social Performance Scale were administered to evaluate psychological loneliness and social functioning, respectively. We observed lower emotion recognition accuracy, higher loneliness, and poorer social functioning in the BD patients after adjustment for demographic data. Loneliness was negatively associated with global social functioning in both the BD and HC groups. Higher loneliness and lower emotion recognition accuracy were associated with poorer social functioning in euthymic BD in different subdomains. Our study confirmed a subtle impairment of emotion recognition ability in euthymic BD. Loneliness impacts globally on social functioning, while emotion recognition ability may affect specific subdomains of social functioning in euthymic BD. Alleviation of loneliness and enhancement of social cognition might improve social functioning in BD patients.

Loneliness and isolated living status in middle-aged and older adults in Taiwan: exploration on stress-related biomarkers, depressive symptoms, and disability

PURPOSE

Loneliness is a subjective feeling by which an individual perceives a lack of closeness in interpersonal relationships. An isolated living status is linked with higher odds of risky health behavior. The conflicting impacts of loneliness and isolated living status on stress-related biomarkers, depressive symptoms, and disability remain unexplained.

METHODS

Six hundred twenty-nine participants aged 66.0 (SD=7.3) separated into four groups: "Lonely and Isolated," "Not Lonely, but Isolated," "Lonely, but Not Isolated," and "Neither Lonely, nor Isolated," were retrieved from the Social Environment and Biomarkers of Aging Study conducted in 2000. Follow-up health indicators in 2006 included three stress-related biomarkers, depressive symptoms, and two physical disability indicators. A hierarchical regression was performed for the analysis.

RESULTS

Firstly, compared to the "Neither Lonely nor Isolated" group, only the "Lonely, but Not Isolated" participants at baseline retained positive associations with the stress-related biomarkers levels 6 years later (urine cortisol level (B=9.25, 95% CI=3.24-15.27), serum Interleukin-6 level (B=2.76, 95% CI=0.72-4.79) and the serum high sensitivity C-reactive protein (hsCRP) level (B=0.40, 95% CI=0.17-0.62)). However, such associations were not observed in the "Lonely and Isolated" participants. Secondly, only "Lonely and Isolated" participants at baseline were positively associated with depressive symptoms 6 years later (B=1.70, 95% CI=0.11-3.30). Finally, the associations between combinations of loneliness and isolated living status and physical disability were eliminated after adjusting the covariables.

CONCLUSION

Four combinations of loneliness and isolated living status were associated with different impacts on stress-related biomarkers, depressive symptoms, and physical disability. Further dynamic investigations are warranted.

Absence of negative associations of insular and medial frontal gray matter volume with dissociative symptoms in schizophrenia

BACKGROUND

Dissociative symptoms have been constantly found in schizophrenia (SCZ). Traumatic experience seems to relate to dissociative symptoms and brain volume alterations in SCZ. The current study aimed to clarify the inter-relations of dissociative symptoms, traumatic experience, and brain volume in SCZ.

METHODS

We employed voxel-based morphometry to compare the distributions of gray matter volumes (GMV) in 37 SCZ patients and 26 healthy volunteers (HV). All participants underwent T1-weighted images on a 1.5 T MRI system. Traumatic experience was examined by the Brief Betrayal Trauma Survey. Pathological and non-pathological dissociation were measured by the Dissociative Symptoms Scale and the Dissociative Experiences Scale, respectively.

RESULTS

A GMV reduction was found in SCZ patients in the right thalamus. Importantly, a significant group by pathological dissociation interaction was observed in the medial frontal cortex (MFC), bilateral anterior insular area, and precuneus. A negative correlation between MFC/insular GMV and pathological dissociation was observed in HV; higher non-pathological dissociation and smaller volume in MFC/insula were associated with pathological dissociation. In contrast, higher traumatic experience, higher non-pathological dissociation, and larger volume in MFC/insula were associated with pathological dissociation in SCZ.

CONCLUSION

The negative association between MFC/insula GMV and pathological dissociation in HV was not observed in SCZ patients. The absent negative association in SCZ suggests a unique neural underpinning in SCZ with dissociative pathology, in which medial frontal and temporal regions play crucial roles.

Add-on repetitive transcranial magnetic stimulation in patients with opioid use disorder undergoing methadone maintenance therapy

Background: Repetitive transcranial magnetic stimulation (rTMS) shows potential therapeutic effects for individuals with addiction, but few studies have examined individuals with opioid use disorder (OUD).Objectives: We conducted an add-on double-blinded, sham-controlled rTMS feasibility pilot trial to examine OUD participants undergoing methadone maintenance therapy (MMT). The current report focused on the effects of rTMS on (1) craving and heroin use behavior and (2) depression, impulsivity, and attention.Methods: Active or sham rTMS treatment was applied to the left dorsolateral prefrontal cortex (DLPFC) over a total of 11 sessions in 4 weeks (15-Hz frequency, 4 seconds per train, intertrain interval of 26 seconds, 40 trains per session) in OUD participants (ClinicalTrials.gov registration number: NCT03229642). Craving, heroin use severity, urine morphine tests, the Hamilton Depression Rating Scale (HDRS), the Barratt Impulsiveness Scale-11 (BIS-11), and the Continuous Performance Tests (CPTs) were measured.Results: Twenty-two OUD participants were enrolled, of which eleven (8 males) were undergoing active rTMS and nine (8 males) were in the sham rTMS group. After 12 weeks of follow-up, the active rTMS group did not show significantly greater improvements than the sham group with respect to craving, heroin use, or urine morphine test results. However, HDRS scores, BIS-11 attentional subscales, and CPTs commission T-scores (C-TS) were significantly lower in the active rTMS group (P = .003, 0.04, and 0.02, respectively) than in the sham group.Conclusion: Add-on rTMS did not appear to improve heroin use behavior but may have benefitted depressive symptoms, impulse control and attention in OUD participants undergoing MMT.

Association of visual motor processing and social cognition in schizophrenia

Patients with schizophrenia have difficulties in social cognitive domains including emotion recognition and mentalization, and in sensorimotor processing and learning. The relationship between social cognitive deficits and sensorimotor function in patients with schizophrenia remains largely unexplored. With the hypothesis that impaired visual motor processing may decelerate information processing and subsequently affects various domains of social cognition, we examined the association of nonverbal emotion recognition, mentalization, and visual motor processing in schizophrenia. The study examined mentalization using the verbal subset of the Chinese version of Theory of Mind (CToM) Task, an equivalent task of the Faux Pas Test; emotion recognition using the Diagnostic Analysis of Nonverbal Accuracy 2-Taiwan version (DANVA-2-TW), and visual motor processing using a joystick tracking task controlled for basic motor function in 34 individuals with chronic schizophrenia in the community and 42 healthy controls. Patients with schizophrenia had significantly worse performance than healthy controls in social cognition, including facial, prosodic emotion recognition, and mentalization. Visual motor processing was also significantly worse in patients with schizophrenia. Only in patients with schizophrenia, both emotion recognition (mainly in prosodic modality, happy, and sad emotions) and mentalization were positively associated with their learning capacity of visual motor processing. These findings suggest a prospective role of sensorimotor function in their social cognitive deficits. Despite that the underlying neural mechanism needs further research, our findings may provide a new direction for restoration of social cognitive function in schizophrenia by enhancing visual motor processing ability.

l-Cystine is associated with the dysconnectivity of the default-mode network and salience network in attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Distributed dysconnectivity within both the default-mode network (DMN) and the salience network (SN) has been observed in ADHD. L-cystine may serve as a neuroprotective molecule and signaling pathway, as well as a biomarker of ADHD. The purpose of this study was to explore whether differential brain network connectivity is associated with peripheral L-cystine levels in ADHD patients. We recruited a total of 31 drug-naïve patients with ADHD (mean age: 10.4 years) and 29 healthy controls (mean age: 10.3 years) that underwent resting state functional magnetic resonance imaging scans. Functional connectomes were generated for each subject, and we examined the cross-sectional group difference in functional connectivity (FC) within and between DMN and SN. L-cystine plasma levels were determined using high-performance chemical isotope labeling (CIL)-based liquid chromatography-mass spectrometry (LC-MS). Compared to the control group, the ADHD group showed decreased FC of dorsal DMN (p = 0.031), as well as decreased FC of precuneus-post SN (p = 0.006) and ventral DMN-post SN (p = 0.001). The plasma L-cystine levels of the ADHD group were significantly higher than in the control group (p = 0.002). Furthermore, L-cystine levels were negatively correlated with FC of precuneus-post SN (r = -0.404, p = 0.045) and ventral DMN-post SN (r = -0.540, p = 0.007). The findings suggest that decreased synergies of DMN and SN may serve as neurobiomarkers for ADHD, while L-cystine may be involved in the pathophysiology of network dysconnectivity. Future studies on the molecular mechanism of the cystine-glutamate system in brain network connectivity are warranted.

Positive Symptoms in Antipsychotic-naïve Schizophrenia are Associated with Increased Body Mass Index after Treatment

Objective

Weight gain is an important risk factor for morbidity and mortality among patients with schizophrenia. We speculated that positive symptoms, related to dopaminergic hyperactivity and altered mesolimbic function, are associated with weight gain.

Methods

Twenty-two antipsychotic-naïve, first-episode patients with schizophrenia were enrolled. The Positive and Negative Syndrome Scale was completed at enrollment and follow-up. Body mass index (BMI) was also measured.

Results

The increase in BMI, after 6.04 ± 2.16 years of follow-up, was associated with positive symptoms, but not negative symptoms, before treatment with antipsychotics in antipsychotic-naïve patients with schizophrenia.

Conclusion

This finding implied that dopaminergic hyperactivity could be an important factor to predict the treatment outcome. Body weight control is important for the health management of patients with schizophrenia with more severe positive symptoms.

Impairment in Emotional Intelligence May Be Mood-Dependent in Bipolar I and Bipolar II Disorders

Background: An emotional intelligence (EI) deficit has been noticed in euthymic bipolar spectrum disorder (BD) patients. However, whether this deficit is affected by mood or subtype is unclear. Objectives:The aim of this study was to investigate whether an EI deficit is mood-dependent, and which mood symptoms have more impact on EI in BD. Methods: Two hundred and thirty participants aged between 18 and 65 years old were recruited [130 BD patients (51 bipolar I disorder (BDI) and 79 bipolar II disorder (BDII): 39.2% males; 91 healthy controls (HCs): 48.4% males)]. The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT), which contains experiential and strategic EI ratings, was used to assess social cognition. The Hamilton Depression Rating Scale (HDRS) and the Young's Mania Rating Scale (YMRS) were used for evaluating the severity [HAMD and YMRS scores ≦7 were euthymic (BDeut) and HAMD YMRS sores ≧8 were episodic (BDepi)]. Analyses of covariance (ANCOVA) were performed, with adjustment for background information between the BD patients and HCs. Results: The results showed that, compared to the HCs, the BDeut patients showed no difference in any MSCEIT measures, while the BDepi patients showed lower scores in all MSCEIT measures, except for perceiving emotions. In addition, a main effect of mood state instead of BD subtype was found for the managing emotions branch (p < 0.0007). Regression analyses showed that the duration of illness and HDRS scores were correlated with the scores in the strategic area of the MSCEIT, while age and YMRS scores were more relevant to the scores in the experiential area of the MSCEIT. Conclusion: The results confirm that an EI deficit is mood-dependent in BD patients. In addition, a depressive mood is more related to the strategic EI area, while a manic mood is correlated with the experiential EI area. Understanding the different domains of EI deficits in BD patients may be helpful for developing interventions for BD.

Childhood neglect is associated with corticostriatal circuit dysfunction in bipolar disorder adults

Bipolar disorder (BD) is characterized with cognitive impairment, which may be mediated by corticostriatal dysfunction. Here we examined whether history of childhood trauma, a risk factor for BD, was linked to corticostriatal dysfunction in BD patients. Furthermore, the possible associations between childhood trauma and cognitive impairment were examined. Thirty-eight BD participants who met the DSM-IV diagnostic criteria were enrolled. Childhood trauma was identified via the Childhood Trauma Questionnaire (CTQ). Participants completed the Wisconsin Card-Sorting Test (WCST). Resting-state functional magnetic resonance imaging (rsfMRI) was performed in participants using a 3T scanner. Bilateral caudate to whole-brain functional connectivity (FC) were analyzed, and childhood trauma was entered as a regressor of interest when controlling for age. Results showed the level of physical neglect was negatively correlated with left-caudate-seed FC to the frontoparietal network, including the right supramarginal gyrus, left inferior parietal lobule, right middle frontal gyrus, and right superior parietal lobule. The level of physical neglect was also negatively correlated with WCST performance. And the left-caudate-seed FCs to the frontoparietal network were positively correlated with WCST performance. Unequivocally, the specific impacts of physical neglect on brain connectivity and executive function in the BD population merit further investigation.

Peripheral inflammation is associated with dysfunctional corticostriatal circuitry and executive dysfunction in bipolar disorder patients

Bipolar disorder (BD) has been linked to abnormal frontal and striatal function, and elevated inflammatory responses. However, the impact of peripheral inflammation on the corticostriatal functional connectivity (FC) remains obscure in BD. The current study aimed to explore the association between peripheral inflammation and corticostriatal connectivity in euthymic BD. We recruited 25 euthymic BD patients and 43 healthy controls (HCs) from the community. Resting state functional images were obtained using 3T magnetic resonance imaging (fMRI), and striatal seed-based whole-brain functional connectivity analyses were performed, with the fasting plasma high-sensitivity C-reactive protein (hs-CRP) level entered as a regressor of interest. The participants also completed the Wisconsin Card-Sorting Test (WCST) and the Continuous Performance Test (CPT). The euthymic BD group had a similar hs-CRP level to the HC group, but a significantly poorer cognitive performance. Compared with the HC group, a higher connectivity between the right dorsal caudal putamen (dcP) and the ventral lateral prefrontal cortex (vlPFC) in the BD group was significantly correlated with a higher hs-CRP level. Stronger dcP-vlPFC connectivity was correlated with a lower CPT unmasked d' in the BD group. BD patients might be particularly sensitive to the effects of inflammation on corticostriatal connectivity. The potentially greater sensitivity of BD patients to peripheral inflammation may differentially modulate the cognitive and reward related corticostriatal circuitry, which may contribute to the pathophysiology of cognitive-affective dysregulation in the euthymic state. Anti-inflammatory or other circuit-specific treatment is warranted for individualized treatment in BD.

The social cognitive ability in Han Chinese euthymic patients with bipolar I and bipolar II disorder

BACKGROUND/PURPOSE

Although social cognitive deficits were found in euthymic patients of bipolar disorder (BD), the characteristics of social cognition in Han Chinese euthymic BD patients remain obscure. This study aimed to examine social cognition in Han Chinese euthymic BD patients relative to healthy controls (HC). Moreover, we explore the differences in social cognition between euthymic BD I and BD II patients.

METHODS

43 Han Chinese BD patients (BD-I:25, BD-II:18) and 28 HC were recruited. All patients were euthymic (Young Mania Rating Scale (YMRS) ≤ 7 and Hamilton Depression Rating Scale (HDRS) ≤ 7). Social cognitive ability was measured using Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT), including 4 branches: perceiving emotions, facilitating emotions, understanding emotions, and managing emotions. Continuous performance Test (CPT) and Wisconsin Card Sorting Test (WCST) were used to examine attention and executive function.

RESULTS

Significant difference in understanding emotions branch of MSCEIT was found between BD patients and HCs (Mann-Whitney U test, p = 0.005). Besides, BD patients had significantly worse performance in WCST and CPT. However, the differences in WCST, CPT, MSCEIT total scores and its subscales were not significant between BD I and BD II patients.

CONCLUSION

Euthymic Han Chinese BD patients exhibit significant social cognitive deficits in understanding emotion and cognitive dysfunction in attention and executive function. Furthermore, Han Chinese BD I patients showed similar social cognitive and general cognitive ability as compared with BD II patients. Social cognitive rehabilitation on both euthymic BD I and II patients should be considered.

The integrated model of glutamate and dopamine hypothesis for schizophrenia: Prediction and personalized medicine for prevent potential treatment-resistant patients

Treatment-resistant schizophrenia (TRS) is one of the subgroups of schizophrenia of which little is known with regard to its optimal mechanism. Treatment response, either as full remission of symptoms or prediction by biomarker, is important in psychiatry. We have proposed a model that integrates dopaminergic and glutamatergic systems with the biological interactions of TRS patients. We hypothesize that the subgroups of schizophrenia may be determined by glutamatergic and dopaminergic concentrations prior to medical treatment. This hypothesis implies that higher glutamatergic concentration in the brain with normalized or decreased dopamine synthesis capacity may explain aspects of TRS as observed in clinical medical practice, neuroimaging measurements, and brain stimulations. According to this hypothesis, the ability to prescribe a proper medication combination, to predict the outcome in first-episode psychosis, and personalized medicine for chronic schizophrenia patients can be applied into practice. This represents an initial step in explaining psychosis due to the valence of two neurotransmitters. Future studies are needed to examine the validity of this mechanism.

Dysregulation of oxytocin and dopamine in the corticostriatal circuitry in bipolar II disorder

The oxytocin (OXT) and dopamine systems synergistically facilitate striatal reactivity. Abnormal striatal activation has repeatedly been observed in patients with bipolar disorder (BD); however, such abnormality remains unclear in BD II. Here we aimed to investigate whether the corticostriatal connectivity was altered and the possible relationships among corticostriatal connectivity, OXT, and dopamine systems in BD II. Twenty-five BD II patients, as defined by the DSM-V, and 29 healthy controls (HC) were enrolled in this study. Plasma OXT was measured and striatal dopamine transporter (DAT) availability was assessed using [^99mTc]TRODAT-1 single-photon emission computed tomography (SPECT). Brain network functional connectivity (FC) was measured during the resting-state using functional magnetic resonance imaging, and the dorsal caudate (DC) was selected as the seed region. The results showed that the OXT level was significantly lower in the BD II patients, while the striatal DAT availability was not significantly different between the BD II and HC groups. The BD II patients exhibited significantly lower FC between the DC and the executive control network (dorsolateral prefrontal, anterior cingulate cortex, and posterior parietal cortex) as compared with the HC. Only observed in HC, the DC-posterior parietal cortex FC was negatively correlated with the OXT level and striatal DAT availability. Our findings in the HC support a model in which the OXT and dopamine systems act in tandem to regulate corticostriatal circuitry, while the synergistic interaction was perturbed in BD II. Taken together, these results implied a maladaptive neuroplasticity in BD II.

Nonlinear Effects of Dopamine D1 Receptor Activation on Visuomotor Coordination Task Performance

Dopamine plays an important role in the modulation of neuroplasticity, which serves as the physiological basis of cognition. The physiological effects of dopamine depend on receptor subtypes, and the D1 receptor is critically involved in learning and memory formation. Evidence from both animal and human studies shows a dose-dependent impact of D1 activity on performance. However, the direct association between physiology and behavior in humans remains unclear. In this study, four groups of healthy participants were recruited, and each group received placebo or medication inducing a low, medium, or high amount of D1 activation via the combination of levodopa and a D2 antagonist. After medication, fMRI was conducted during a visuomotor learning task. The behavioral results revealed an inverted U-shaped effect of D1 activation on task performance, where medium-dose D1 activation led to superior learning effects, as compared to placebo as well as low- and high-dose groups. A respective dose-dependent D1 modulation was also observed for cortical activity revealed by fMRI. Further analysis demonstrated a positive correlation between task performance and cortical activation at the left primary motor cortex. Our results indicate a nonlinear curve of D1 modulation on motor learning in humans and the respective physiological correlates in corresponding brain areas.

Bridging the associations between dopamine, brain volumetric variation and IQ in drug-naïve schizophrenia

BACKGROUND

Although patients with schizophrenia are well-known to exhibit significant brain volume reduction and cognitive function impairment, it remains unclear as to whether the reduction/impairment is correlated with dopaminergic activity under drug-naïve conditions.

METHODS

51 drug-naïve patients with and 128 healthy subjects were recruited in this study. DAT by [^99mTc]TRODAT-1 single-photon emission computed tomography (SPECT), regional gray matter volume (GMV) by voxel-based morphometry (VBM) analysis, and cognitive function in terms of IQ were measured in both groups.

RESULT

A significantly lower DAT availability existed in the drug-naïve group as compared with the healthy subjects (1.67 ± 0.45 vs. 1.98 ± 0.37, P < 0.005). DAT availability was significantly positively correlated with GMV in the left middle frontal lobe (r = 0.58, P < 0.005), the GMV being significantly reduced in the patients with schizophrenia (0.45 ± 0.10 vs. 0.49 ± 0.07, P < 0.005). Furthermore, the GMV in the left middle frontal lobe was significantly and positively correlated with full IQ (r = 0.34, P = 0.02) in the patients with schizophrenia, but not in the controls.

CONCLUSIONS

Dysregulated dopaminergic activity may modulate volume variation in specific brain areas, and brain volume might alter IQ in drug-naïve patients with schizophrenia.

The Interaction of Oxytocin and Social Support, Loneliness, and Cortisol Level in Major Depression

Objective

Loneliness is a specific risk factor for depressive symptoms and suicidal behavior. The present study examined whether the serum oxytocin level would interact with social support and buffers loneliness and hypothalamic-pituitary-adrenal (HPA)-axis activity in drug-naïve patients with major depressive disorder (MDD).

Methods

Twenty-six patients with MDD (male:female = 3:23; mean age, 45.54 ± 12.97 years) were recruited. The 17-item Hamilton Depression Rating Scale, UCLA Loneliness Scale and self-reported Measurement of Support Function Questionnaire were administered. Serum oxytocin and cortisol levels were assessed using a commercial immunoassay kits.

Results

In MDD patients, a negative association was found between degrees of social support and loneliness (β = −0.39, p = 0.04). The interaction between social support and serum oxytocin level was negatively associated with loneliness (β = −0.50, p = 0.017) and serum cortisol level (β = −0.55, p = 0.020) after adjusting for age. Follow-up analyses showed that the association between higher social support and lower loneliness was observed only in the higher-oxytocin group (r = −0.75, p = 0.003) but not in the lower group (r = −0.19, p = 0.53). The significance remained after further adjusting for sex and depression severity.

Conclusion

Low oxytocin level is a vulnerability factor for the buffering effect of social support for loneliness and aberrant HPA-axis activity in MDD patients.

Preliminary data indicating a connection between stress-induced prefrontal dopamine release and hippocampal TSPO expression in the psychosis spectrum

Prolonged stress can cause neuronal loss in the hippocampus resulting in disinhibition of glutamatergic neurons proposed to enhance dopaminergic firing in subcortical regions including striatal areas. Supporting this, imaging studies show increased striatal dopamine release in response to psychosocial stress in healthy individuals with low childhood maternal care, individuals at clinical high risk for psychosis (CHR) and patients with schizophrenia. The prefrontal cortex (PFC) is connected to the hippocampus and a key region to control neurochemical responses to stressful stimuli. We recently reported a disrupted PFC dopamine-stress regulation in schizophrenia, which was intact in CHR. Given the available evidence on the link between psychosocial stress, PFC dopamine release and hippocampal immune activation in psychosis, we explored, for the first time in vivo, whether stress-induced PFC dopamine release is associated with hippocampal TSPO expression (a neuroimmune marker) in the psychosis spectrum. We used an overlapping sample of antipsychotic-naïve subjects with CHR (n = 6) and antipsychotic-free schizophrenia patients (n = 9) from our previously published studies, measuring PFC dopamine release induced by a psychosocial stress task with [¹¹C]FLB457 positron emission tomography (PET) and TSPO expression with [¹⁸F]FEPPA PET. We observed that participants on the psychosis spectrum with lower stress-induced dopamine release in PFC had significantly higher TSPO expression in hippocampus (β = -2.39, SE = 0.96, F(1,11) = 6.17, p = 0.030). Additionally, we report a positive association between stress-induced PFC dopamine release, controlled for hippocampal TSPO expression, and Global Assessment of Functioning. This is the first exploration of the relationship between PFC dopamine release and hippocampal TSPO expression in vivo in humans.

Prefrontal cortical dopamine release in clinical high risk for psychosis during a cognitive task: a [11C]FLB457 positron emission tomography study

Research suggests decreased cortical dopamine is a neural correlate of cognitive deficits in schizophrenia. Evidence of impaired cognitive task-induced cortical dopamine release was demonstrated in patients with psychosis. However, whether cortical dopamine release in response to a cognitive task in clinical high risk for psychosis (CHR) is also impaired, is currently unknown. We aimed to test dopamine release in the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) in antipsychotic-free CHR participants and healthy controls (HC) performing the Wisconsin Card Sorting Task (WCST). Two [¹¹C]FLB457 PET scans were conducted for 13 CHR and 15 HC while performing the WCST and the sensorimotor control task (SMCT), respectively. A magnetic resonance image was acquired for anatomical delineation. Percentage change in binding potential (ΔBP_ND) in ACC and DLPFC in WCST were compared with the SMCT between CHR and HC. Mixed model analysis revealed no statistically significant differences in the cognitive task induced ΔBP_ND in any ROIs. There were no main effect of group (F(1, 26) = 0.348; p = 0.560) or ROI (F(1, 26) = 1.080; p = 0.308) and no significant Group x ROI interaction (F(1, 26) = 0.049; p = 0.826). Our findings suggest no statistically significant difference between CHR and HC in cognitive task-induced cortical dopamine release. This is the first in vivo study to illustrate that the cortical hypodopaminergic state observed in schizophrenia may not be present in its putative high-risk state.

Negative Interpretation Biases Precede the Onset of Psychosis

This study investigated whether a negative interpretation bias was present in people at high risk for psychosis. People with an At Risk Mental State (ARMS; n = 21), patients with First Episode Psychosis (FEP; n = 20), and healthy controls (n = 20) performed three tasks, each of which was designed to measure interpretation bias. Both ARMS and FEP participants showed an attenuated positive bias compared to controls. These findings extend previous results investigating interpretation bias in psychosis by showing that interpretative biases are present before the onset of psychosis, and could therefore contribute to its development. Biased interpretation mechanisms could be a new target for clinical intervention in the early phase of psychosis.

Attachment avoidance and fearful prosodic emotion recognition predict depression maintenance

Insecure attachment cognitions, emotion recognition biases, and their interaction are important contributors to depression susceptibility. The present study, with a prospective longitudinal design, investigated the role of negative emotion recognition in moderating the linkage from insecure attachment cognitions to elevated depressive symptoms. A sample of 96 depression-prone individuals completed measures for attachment anxiety and attachment avoidance, depression symptom severity, and a computerized facial and prosodic emotion recognition task twice with a four-week interval. Results revealed that the interaction between attachment avoidance and fearful prosodic emotion recognition significantly predicted subsequent depressive symptoms. More specifically, greater attachment avoidance with lower accuracy of fearful prosodic emotions at baseline predicted an increase of depressive symptoms over four-week interval. However, no moderating role of emotion recognition in the linkage from attachment anxiety to depression persistence was noted. The present study demonstrates that attachment avoidance and negative emotion recognition may together contribute to the maintenance of depression. The findings may be pertinent to attachment avoidance-related deactivating strategy that appears to be a specific cultural forbearance way for emotion regulation in collectivistic societies. Potential applications and future research are then suggested.

Cortical stress regulation is disrupted in schizophrenia but not in clinical high risk for psychosis

While alterations in striatal dopamine in psychosis and stress have been well studied, the role of dopamine in prefrontal cortex is poorly understood. To date, no study has investigated the prefrontocortical dopamine response to stress in the psychosis spectrum, even though the dorsolateral and medial prefrontal cortices are key regions in cognitive and emotional regulation, respectively. The present study uses the high-affinity dopamine D2/3 receptor radiotracer 11C-FLB457 and PET together with a validated psychosocial stress challenge to investigate the dorsolateral and medial prefrontocortical dopamine response to stress in schizophrenia and clinical high risk for psychosis. Forty participants completed two 11C-FLB457 PET scans (14 antipsychotic-free schizophrenia, 14 clinical high risk for psychosis and 12 matched healthy volunteers), one while performing a Sensory Motor Control Task (control) and another while performing the Montreal Imaging Stress Task (stress). Binding potential (BPND) was estimated using Simplified Reference Tissue Model with cerebellar cortex as reference region. Dopamine release was defined as per cent change in BPND between control and stress scans (ΔBPND) using a novel correction for injected mass. Salivary cortisol response (ΔAUCI) was assessed throughout the tasks and its relationship with dopamine release examined. 11C-FLB457 binding at control conditions was significantly different between groups in medial [F(2,37) = 7.98, P = 0.0013] and dorsolateral [F(2,37) = 6.97, P = 0.0027] prefrontal cortex with schizophrenia patients having lower BPND than participants at clinical high risk for psychosis and healthy volunteers, but there was no difference in ΔBPND among groups [dorsolateral prefrontal cortex: F(2,37) = 1.07, P = 0.35; medial prefrontal cortex: F(2,37) = 0.54, P = 0.59]. We report a positive relationship between ΔAUCI and 11C-FLB457 ΔBPND in dorsolateral and medial prefrontal cortex in healthy volunteers (r = 0.72, P = 0.026; r = 0.76, P = 0.014, respectively) and in participants at clinical high risk for psychosis (r = 0.76, P = 0.0075; r = 0.72, P = 0.018, respectively), which was absent in schizophrenia (r = 0.46, P = 1.00; r = 0.19, P = 1.00, respectively). Furthermore, exploratory associations between ΔBPND or ΔAUCI and stress or anxiety measures observed in clinical high risk for psychosis were absent in schizophrenia. These findings provide first direct evidence of a disrupted prefrontocortical dopamine-stress regulation in schizophrenia.

Nigral Stress-Induced Dopamine Release in Clinical High Risk and Antipsychotic-Naïve Schizophrenia

Background

Striatal dopamine (DA) synthesis capacity and release are elevated in schizophrenia (SCZ) and its putative prodrome, the clinical high risk (CHR) state. Striatal DA function results from the activity of midbrain DA neurons projecting mainly from the substantia nigra (SN). Elevated stress-induced DA release in SCZ and CHR was observed in the striatum; however, whether it is also elevated in the SN is unclear. The current study aims to determine whether nigral DA release in response to a validated stress task is altered in CHR and in antipsychotic-naïve SCZ. Further, we explore how DA release in the SN and striatum might be related.

Methods

24 CHR subjects, 9 antipsychotic-naïve SCZ and 25 healthy volunteers (HV) underwent 2 positron emission tomography (PET) scans using the DA D2/3 agonist radiotracer, [11C]-(+)-PHNO, which allows simultaneous investigations of DA in the SN and striatum. Psychosocial stress-induced DA release was estimated as the percentage differences in BPND (%[11C]-(+)-PHNO displacement) between stress and sensory-motor control sessions.

Results

We observed a significant diagnostic group by session interaction, such that SCZ exhibited greater stress-induced [11C]-(+)-PHNO % displacement (25.90% ± 32.2%; mean ± SD), as compared to HVs (-10.94% ± 27.1%). Displacement in CHRs (-1.13% ± 32.2%) did not differ significantly from either HV or SCZ.

Conclusion

Our findings suggest that elevated nigral DA responsiveness to stress is observed in antipsychotic-naïve SCZ.

Facial and prosodic emotion recognition in social anxiety disorder

INTRODUCTION

Patients with social anxiety disorder (SAD) have a cognitive preference to negatively evaluate emotional information. In particular, the preferential biases in prosodic emotion recognition in SAD have been much less explored. The present study aims to investigate whether SAD patients retain negative evaluation biases across visual and auditory modalities when given sufficient response time to recognise emotions.

METHODS

Thirty-one SAD patients and 31 age- and gender-matched healthy participants completed a culturally suitable non-verbal emotion recognition task and received clinical assessments for social anxiety and depressive symptoms. A repeated measures analysis of variance was conducted to examine group differences in emotion recognition.

RESULTS

Compared to healthy participants, SAD patients were significantly less accurate at recognising facial and prosodic emotions, and spent more time on emotion recognition. The differences were mainly driven by the lower accuracy and longer reaction times for recognising fearful emotions in SAD patients. Within the SAD patients, lower accuracy of sad face recognition was associated with higher severity of depressive and social anxiety symptoms, particularly with avoidance symptoms.

CONCLUSION

These findings may represent a cross-modality pattern of avoidance in the later stage of identifying negative emotions in SAD. This pattern may be linked to clinical symptom severity.

Elevated Striatal Dopamine Function in Immigrants and Their Children: A Risk Mechanism for Psychosis

Migration is a major risk factor for schizophrenia but the neurochemical processes involved are unknown. One candidate mechanism is through elevations in striatal dopamine synthesis and release. The objective of this research was to determine whether striatal dopamine function is elevated in immigrants compared to nonimmigrants and the relationship with psychosis. Two complementary case-control studies of in vivo dopamine function (stress-induced dopamine release and dopamine synthesis capacity) in immigrants compared to nonimmigrants were performed in Canada and the United Kingdom. The Canadian dopamine release study included 25 immigrant and 31 nonmigrant Canadians. These groups included 23 clinical high risk (CHR) subjects, 9 antipsychotic naïve patients with schizophrenia, and 24 healthy volunteers. The UK dopamine synthesis study included 32 immigrants and 44 nonimmigrant British. These groups included 50 CHR subjects and 26 healthy volunteers. Both striatal stress-induced dopamine release and dopamine synthesis capacity were significantly elevated in immigrants compared to nonimmigrants, independent of clinical status. These data provide the first evidence that the effect of migration on the risk of developing psychosis may be mediated by an elevation in brain dopamine function.

Imaging Microglial Activation in Untreated First-Episode Psychosis: A PET Study With [18F]FEPPA

OBJECTIVE

Neuroinflammation and abnormal immune responses are increasingly implicated in the pathophysiology of schizophrenia. Previous positron emission tomography (PET) studies targeting the translocator protein 18 kDa (TSPO) have been limited by high nonspecific binding of the first-generation radioligand, low-resolution scanners, small sample sizes, and psychotic patients being on antipsychotics or not being in the first episode of their illness. The present study uses the novel second-generation TSPO PET radioligand [18F]FEPPA to evaluate whether microglial activation is elevated in the dorsolateral prefrontal cortex and hippocampus of untreated patients with first-episode psychosis.

METHOD

Nineteen untreated patients with first-episode psychosis (14 of them antipsychotic naive) and 20 healthy volunteers underwent a high-resolution [18F]FEPPA PET scan and MRI. Dynamic PET data were analyzed using the validated two-tissue compartment model with arterial plasma input function with total volume of distribution (VT) as outcome measure. All analyses were corrected for TSPO rs6971 polymorphism (which is implicated in differential binding affinity).

RESULTS

No significant differences were observed between patients and healthy volunteers in microglial activation, as indexed by [18F]FEPPA VT, in either the dorsolateral prefrontal cortex or the hippocampus. There were no significant correlations between [18F]FEPPA VT and duration of illness, clinical presentation, or neuropsychological measures after adjusting for multiple testing.

CONCLUSIONS

The lack of significant differences in [18F]FEPPA VT between groups suggests that microglial activation is not present in first-episode psychosis.

Corticolimbic dysfunction during facial and prosodic emotional recognition in first-episode psychosis patients and individuals at ultra-high risk

Emotional processing dysfunction is widely reported in patients with chronic schizophrenia and first-episode psychosis (FEP), and has been linked to functional abnormalities of corticolimbic regions. However, corticolimbic dysfunction is less studied in people at ultra-high risk for psychosis (UHR), particularly during processing prosodic voices. We examined corticolimbic response during an emotion recognition task in 18 UHR participants and compared them with 18 FEP patients and 21 healthy controls (HC). Emotional recognition accuracy and corticolimbic response were measured during functional magnetic resonance imaging (fMRI) using emotional dynamic facial and prosodic voice stimuli. Relative to HC, both UHR and FEP groups showed impaired overall emotion recognition accuracy. Whilst during face trials, both UHR and FEP groups did not show significant differences in brain activation relative to HC, during voice trials, FEP patients showed reduced activation across corticolimbic networks including the amygdala. UHR participants showed a trend for increased response in the caudate nucleus during the processing of emotionally valenced prosodic voices relative to HC. The results indicate that corticolimbic dysfunction seen in FEP patients is also present, albeit to a lesser extent, in an UHR cohort, and may represent a neural substrate for emotional processing difficulties prior to the onset of florid psychosis.

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Emotional processing deficits in psychosis are linked to corticolimbic dysfunction.

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Corticolimbic dysfunction is less studied at ultra-high risk stage for psychosis.

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Both UHR and FEP groups showed impaired emotion recognition accuracy.

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Reduced activation across corticolimbic networks is observed in FEP group.

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Subtle corticolimbic dysfunction may also exist in UHR cohort.

Neural correlates of aberrant emotional salience predict psychotic symptoms and global functioning in high-risk and first-episode psychosis

Neurobiological and behavioral findings suggest that psychosis is associated with corticolimbic hyperactivity during the processing of emotional salience. This has not been widely studied in the early stages of psychosis, and the impact of these abnormalities on psychotic symptoms and global functioning is unknown. We sought to address this issue in 18 patients with first-episode psychosis (FEP), 18 individuals at ultra high risk of psychosis (UHR) and 22 healthy controls (HCs). Corticolimbic response and subjective ratings to emotional and neutral scenes were measured using functional magnetic resonance imaging. The clinical and functional impact of corticolimbic abnormalities was assessed with regression analyses. The FEP and UHR groups reported increased subjective emotional arousal to neutral scenes compared with HCs. Across groups, emotional vs neutral scenes elicited activation in the dorsomedial prefrontal cortex, inferior frontal gyrus/anterior insula and amygdala. Although FEP and UHR participants showed reduced activation in these regions when viewing emotional scenes compared with controls, this was driven by increased activation to neutral scenes. Corticolimbic hyperactivity to neutral scenes predicted higher levels of positive symptoms and poorer levels of functioning. These results indicate that disruption of emotional brain systems may represent an important biological substrate for the pathophysiology of early psychosis and UHR states.