Cortical thinning, functional connectivity, and mood-related impulsivity in schizophrenia: relationship to aggressive attitudes and behavior

The relationship between cognitive function and cortical thickness in first-episode drug-naive schizophrenia patients with agitation

Objective

This study aims to explore the relationships between the agitation behavior, cognitive function and cortical thickness in first-episode drug-naïve schizophrenia (FESN).

Methods

A total of 55 male healthy controls (HC) and 79 male inpatients with FESN were enrolled in the present study. Whole brain cortical thickness was extracted from T1-weighted MRI using Freesurfer Version 7.4.1 software package. Cognitive function was evaluated using the MATRICS Consensus Cognitive Battery (MCCB). The Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) is used to divide these inpatients into agitation group (FESN+A) and non-agitation group (FESN+NA). Correlation analysis was employed to investigate the potential associations between cortical thickness and cognitive function.

Results

The FESN+A group had higher Positive and Negative Syndrome Scale (PANSS) total score, positive symptom score, and general psychopathology score than the FESN+NA group. Both the FESN+A/NA groups showed significantly worse performance than the HC in symbol coding, working memory, attention/vigilance, reasoning and problem solving, and social cognition. The FESN+A group performed worse on working memory when comparing to FESN+NA group. Furthermore, the cortical thickness of the left paracalcarine gyrus was increased in the FESN+NA group, compared to HC. FESN+A group had thicker cortical thickness in the right posterior cingulate cortex (rPCC) compared with the FESN+NA group. The cortical thickness of rPCC was negatively correlated with score of working memory in the FESN+A group.

Conclusion

The present study demonstrated that the abnormal cortical thickness of rPCC may be related to the agitation behavior and cognitive function in patients with FESN+A, suggesting a potential treatment target for agitation behavior and cognitive impairment in schizophrenia.

Role of peripheral cytokines and orbitofrontal cortex subregion structure in schizophrenia agitation

This study aimed to examine the potential involvement of inflammatory imbalance and OFC subregion structure in the pathogenesis of agitation. In this study 119 schizophrenia patients were categorized into different subgroups of agitation using two-step cluster analysis. Peripheral cytokine and the OFC structure were examined in all subjects. Patients were assessed for immune-inflammatory response system and compensatory immunoregulatory reflex system (IRS/CIRS) reflecting the level of inflammatory imbalance. The immune biomarkers mainly include M1 (IL-6, IL-1β, IFN-α and TNF-α), T helper, Th-1 (IL-2, IL-12p70 and IFN-γ), Th-2 (IL-4 and IL-5), Th-17 (IL-17) and T regulatory cytokines (Treg) (IL-10). Compared with the low agitation group, the pro-inflammatory cytokine IL-6 was significantly higher in the high agitation group, as were the levels of the immune biomarkers Th-2, M1, IRS and IRS/CIRS. However, there was no significant difference in the OFC volume and cortical thickness between the two groups. In addition, left lateral OFC volume was negatively correlated with IRS/CIRS in the high agitation group. Moderation model showed that agitation significantly moderated the relationship between left lateral OFC volume and IRS/CIRS. Thus, the present study provides assistance in explaining the etiological mechanisms of agitation in schizophrenia.

Spatial patterns of individual morphological deformation in schizophrenia: Putative cortical compensatory of unaffected sibling

BACKGROUND

Neuroimaging advancements have revealed morphological deformation across various indicators, illuminating the neuropathological origins of schizophrenia. However, consolidating the findings across indicators and assessing regional global deformation at individual-level poses a significant challenge.

METHODS

We propose individual morphological deformation index (IMDI) as potential biomarker for schizophrenia leveraging a distance algorithm that incorporates three key indicators (cortical thickness, gyrification, and volume), and applied it for 199 schizophrenia patients, 218 healthy controls, and 47 unaffected siblings. Additionally, we studied the relationships between polygenic risks, symptomology, cognition, social functioning and regional IMDI.

RESULTS

Our findings reveal significantly higher IMDI in specific brain regions (bilateral pars opercularis, lateral orbitofrontal, left superior parietal, right pars orbitalis, and superior temporal) in patients, demonstrating two distinct spatial patterns linked to either isolated indicator reduction or concurrent declines across multiple indicators. Notably, unaffected siblings exhibited higher IMDI than controls, primarily due to cortical volume expansion in the right pars opercularis and superior temporal regions. Patients with higher IMDI had more severe positive symptoms, impaired cognition, reduced social functioning and selfcare ability. Participants with higher polygenic scores showed higher IMDI specifically in left caudal middle frontal regions.

CONCLUSIONS

The proposed IMDI biomarker offers an objective, interpretable way to quantify global regional deformation and integrate disparate neuroimaging indicators. Our results indicate that schizophrenia-related cortical deformations encompass sensorimotor, attention, default mode, and frontoparietal networks, exhibiting at least two spatial patterns. Moreover, siblings may exhibit compensation in cortical volume. These insights offer a novel perspective on the neuroanatomical underpinnings of schizophrenia.

Do residents in proximity to blue spaces exhibit lower emotion-related impulsivity? The mediating role of perceived crowdedness

BACKGROUND

Emotion-related impulsivity (ERI) is a significant predisposing factor for various mental health issues and is influenced by individuals' immediate environment. Previous research has largely focused on mitigating ERI through individual-level interventions without extensively considering the role of the external environment. This study explores the impact of passive blue space exposure (PBSE) on ERI, considering both subjective and objective measures of PBSE and investigating the mediating role of perceived crowdedness.

METHODS

Two studies were conducted using online platforms to collect data from Chinese residents. Study 1 (n = 369) examined the predictive effect of objective PBSE, as assessed by the normalized difference water index (NDWI), on ERI. Study 2 (n = 374) focused on subjective PBSE and the mediating effect of perceived crowdedness on ERI. Descriptive statistics, correlational analyses, and path analyses were employed to evaluate the relationships between PBSE, perceived crowdedness, and ERI.

RESULTS

Study 1 demonstrated a negative correlation between objective PBSE and ERI, with marginal significance in predictive analysis after controlling for covariates. Study 2 revealed that subjective PBSE was significantly negatively associated with ERI, and perceived crowdedness significantly mediated this relationship. Subjective PBSE reduced perceived crowdedness, which in turn decreased ERI, accounting for 20% of the total effect. The findings suggest that PBSE, both objective and subjective, may serve as a protective factor against ERI.

CONCLUSIONS

This research highlights the negative association between PBSE and ERI, extending the understanding of environmental influences on impulsive behavior. It emphasizes the potential of utilizing blue spaces in urban planning and individual exposure to alleviate impulsivity. The study also sheds light on the importance of considering both subjective and objective environmental factors in psychological research and interventions. Future studies should consider a comprehensive approach to measuring PBSE and explore causal relationships through experimental designs.

Cognitive Training for Emotion-Related Impulsivity and Rumination: Protocol for a Pilot Randomized Waitlist-Controlled Trial

BACKGROUND

Inhibitory deficits are common in psychopathology. Emotion-related impulsivity (ERI) and rumination are general risk factors for psychiatric distress that are similarly associated with dysfunctional inhibition-particularly in affective contexts. A number of cognitive remediation procedures have been developed to improve inhibitory control; however, most remediation programs focus on "cold" cognition independent of affective processing. This pilot trial will gather preliminary evidence for a new cognitive training intervention targeting "hot" affective control (ie, inhibitory functions during elevated emotional arousal) in a transdiagnostic sample of adults who report heightened emotion dysregulation.

OBJECTIVE

This manuscript describes a protocol for a pilot randomized waitlist-controlled trial to assess changes in ERI and rumination after neurobehavioral affective control training (N-ACT), an 8-week cognitive training intervention designed to improve emotional response inhibition and emotional working memory. Our primary aim is to evaluate the efficacy, feasibility, and acceptability of N-ACT in reducing rumination and ERI, which we respectively conceptualize as complementary cognitive and behavioral consequences of emotion dysregulation. Secondarily, we will examine whether N-ACT leads to improvements in inhibitory control and, more distally, psychopathology symptoms.

METHODS

The final sample will comprise 80 adults who report high ERI or rumination. Participants will be randomized to (1) begin the N-ACT program without delay or (2) join a waitlist condition and then complete N-ACT. Exclusion criteria include active alcohol or substance use disorders, psychosis, and suicide risk. At the baseline and postintervention time points, participants will complete measures of emotion dysregulation and psychiatric symptoms, as well as a neuropsychological assessment of inhibitory control. Individuals assigned to the control group will undergo an identical assessment before joining the waitlist, followed by parallel assessments before and after N-ACT.

RESULTS

This trial is funded by support from the University of California Board of Regents and the Peder Sather Foundation (funding period: October 2022-September 2025). Recruitment is scheduled to begin in spring 2025. We will begin data analysis once data collection is complete, which is planned to occur in fall 2025.

CONCLUSIONS

This pilot randomized waitlist-controlled trial is designed to assess the initial efficacy, feasibility, and acceptability of N-ACT, a novel cognitive remediation approach developed to address 2 key contributors to psychopathology: ERI and rumination. The N-ACT program uses computerized adaptive behavioral tasks to strengthen the affective control processes theoretically and empirically linked to ERI and rumination. We hope this work will help inform future studies with sufficient statistical power to ascertain whether enhancing affective control through cognitive training (N-ACT) produces downstream reductions in psychiatric symptoms via improved emotion regulation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06226467; https://www.clinicaltrials.gov/study/NCT06226467; Open Science Framework Registry rak5z; https://osf.io/rak5z.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/54221.

The study on agitation and structure of orbitofrontal cortex subregion in first-episode drug-naïve patients with schizophrenia

Agitation is one of the core symptoms of schizophrenia. The occurrence of agitation may be related to orbitofrontal cortex dysfunction. However, due to methodological heterogeneity, the relationship between agitation and orbitofrontal cortex subregions remains unclear. Based on the multi-dimensional structure of the orbitofrontal cortex subregion, this study aims to explore the relationship between orbitofrontal cortex structure and agitation in first-episode drug-naïve patients with schizophrenia. The study subjects included 50 first-episode drug-naïve patients with schizophrenia and 29 healthy controls. All participants underwent structure magnetic resonance imaging scanning. The patients' clinical symptoms were assessed using the Positive and Negative Syndrome Scale, and the agitation were evaluated using the Brief Agitation Rating Scale. SPSS 26.0 was used to compare the differences in the orbitofrontal cortex subregion between the two groups in different structure dimensions and then conduct a Pearson's partial correlations analysis to observe the relationship between orbitofrontal cortex subregion structure and agitation. There were no significant differences in demographic factors between the two groups. Our results show the folding index of the orbitofrontal cortex subregion in patients with schizophrenia were significantly smaller compared to the healthy controls. The surface area in the orbitofrontal cortex subregion is significantly negatively correlated with agitation in first-episode drug-naïve schizophrenia patients. These results suggest that structure alterations in the orbitofrontal cortex subregion may be involved in schizophrenia agitation.

The role of the prefrontal cortex in modulating aggression in humans and rodents

Accumulating evidence suggests that the prefrontal cortex (PFC) plays an important role in aggression. However, the findings regarding the key neural mechanisms and molecular pathways underlying the modulation of aggression by the PFC are relatively scattered, with many inconsistencies and areas that would benefit from exploration. Here, we highlight the relationship between the PFC and aggression in humans and rodents and describe the anatomy and function of the human PFC, along with homologous regions in rodents. At the molecular level, we detail how the major neuromodulators of the PFC impact aggression. At the circuit level, this review provides an overview of known and potential subcortical projections that regulate aggression in rodents. Finally, at the disease level, we review the correlation between PFC alterations and heightened aggression in specific human psychiatric disorders. Our review provides a framework for PFC modulation of aggression, resolves several intriguing paradoxes from previous studies, and illuminates new avenues for further study.

Emotion-related impulsivity is related to orbitofrontal cortical sulcation

BACKGROUND

Emotion-related impulsivity (ERI) describes the trait-like tendency toward poor self-control when experiencing strong emotions. ERI has been shown to be elevated across psychiatric disorders and predictive of the onset and worsening of psychiatric syndromes. Recent work has correlated ERI scores with the region-level neuroanatomical properties of the orbitofrontal cortex (OFC), but not posteromedial cortex (PMC). Informed by a growing body of research indicating that examining the morphology of specific cortical folds (sulci) can produce unique insights into behavioral outcomes, the present study modeled the association between ERI and the morphology of sulci within OFC and PMC, which is a finer scale than previously conducted.

METHODS

Analyses were conducted in a transdiagnostic sample of 118 adult individuals with a broad range of psychiatric syndromes. First, we manually defined over 4,000 sulci across 236 cerebral hemispheres. Second, we implemented a model-based LASSO regression to relate OFC sulcal morphology to ERI. Third, we tested whether effects were specific to OFC sulci, sulcal depth, and ERI (as compared to PMC sulci, sulcal gray matter thickness, and non-emotion-related impulsivity).

RESULTS

The LASSO regression revealed bilateral associations of ERI with the depths of eight OFC sulci. These effects were strongest for OFC sulci, sulcal depth, and ERI in comparison to PMC sulci, sulcal gray matter thickness, and non-emotion-related impulsivity. In addition, we identified a new transverse component of the olfactory sulcus in every hemisphere that is dissociable from the longitudinal component based on anatomical features and correlation with behavior, which could serve as a new transdiagnostic biomarker.

CONCLUSIONS

The results of this data-driven investigation provide greater neuroanatomical and neurodevelopmental specificity on how OFC is related to ERI. As such, findings link neuroanatomical characteristics to a trait that is highly predictive of psychopathology.

Impulsivity as a predictor of clinical and psychological outcomes in a naturalistic prospective cohort of subjects at ultra-high risk (UHR) for psychosis from Tunisia

BACKGROUND

Impulsivity is associated with serious detrimental consequences on physical, mental, behavioral and social aspects of health among patients with psychosis. The present prospective 12-month follow-up study aimed to determine the prevalence of highly impulsive individuals among Ultra High Risk (UHR) patients, how impulsivity evolves over the follow-up period, and whether impulsivity impacts clinical, psychological and functional outcomes in this population.

METHOD

UHR patients were invited to complete a battery of measurements at three-time points: at baseline, and at 6 and 12 months of follow-up. Impulsivity was assessed using both behavioral (the Wisconsin Card Sorting Test, WCST) and self-report (the Barratt Impulsiveness Scale, BIS-11) measures.

RESULTS

Findings showed that at 6 months of follow-up, higher 6-month BIS-11 attentional and motor impulsivity were significantly associated with lower quality of life and greater general psychological distress. In addition, higher baseline BIS-11 motor impulsivity significantly predicted more severe positive psychotic symptoms at 12 months of follow-up. However, WCST scores did not show any significant associations with study variables at the different times of follow-up.

CONCLUSION

Interventions targeting impulsivity in UHR individuals could help decrease psychological distress and positive psychotic symptoms' severity, as well as improve quality of life in UHR individuals.

Contexts of urgency may go beyond emotion

Introduction

Urgency has been defined as the tendency towards rash speech and behavior in the context of emotion. Measures of Urgency have been found to have robust predictive power for psychopathologies and problematic behaviors. In the current study, we question whether emotions are unique drivers of urgency, or if emotions are potent exemplars of contexts that lead to rash speech and behavior. The Emotion Specific model and the Broader Contexts model correspond with these two conceptualizations of urgency, and they frame our pre-registered hypotheses.

Methods

Participants from two well-powered samples (n = 600,n = 588) completed 9 modified items from the Urgency and Positive Urgency scales to assess rash responses in each of four contexts - "Upset," "Excited," "Tired," and "Hungry" - and a fifth "In General" set. After data cleaning, we used principal components analysis to construct a unidimensional, 4-item set that was applied to capture impulsive behavior across the five contexts.

Results

We found that this research tool, called the Contexts of Impulsive Behaviors (CIBS), replicated in the second dataset, and it had adequate internal reliability in both samples. Although the Emotion Specific model was supported by the fact that the Upset context had a greater mean and greater variance than the Tired and Hungry contexts, most results supported the Broader Contexts model. That is, CIBS contexts were highly intercorrelated, and bivariate correlations with psychopathology were not significantly different across contexts. In partial correlations, effects of the Upset and Excited contexts were partially or fully statistically mediated by the Tired and Hungry contexts.

Discussion

These findings suggest that emotions are potent contexts for impulsive behaviors. At the same time, those with high urgency are vulnerable to impulsivity in other contexts, such as fatigue and hunger, that challenge the regulatory functions of the prefrontal cortex. Limitations, future directions, and clinical implications are discussed.

The contribution of alexithymia, childhood maltreatment, impulsivity, C-reactive protein, lipid profile, and thyroid hormones to aggression and psychological distress (depression and anxiety) in schizophrenia

There are individual effects of alexithymia, childhood maltreatment, impulsivity, and some biological markers on aggression and psychological distress in schizophrenia. However, the combined effects of these psychological and biological markers have not yet been fully studied. This study therefore aimed to investigate the influence of these psychological and biological markers on aggression and psychological distress (e.g., depression and anxiety) in inpatients with schizophrenia (n = 355). Participants completed self-report and clinician-rated scales, and blood samples were collected. There were no significant differences between patients with and without alexithymia regarding biological markers. Patients with childhood maltreatment exhibited higher levels of free triiodothyronine (FT3) and C-reactive protein (CRP), as well as lower total cholesterol (TC) levels, compared to non-traumatized individuals. Aggression was positively predicted by psychological distress, alexithymia, childhood maltreatment, impulsivity, CRP, and FT3, and negatively by TC and low-density lipoprotein cholesterol. Negative symptoms, childhood maltreatment, alexithymia, aggression, and CRP positively, and high-density lipoprotein cholesterol negatively emerged as predictors of psychological distress. The study highlights the connections between childhood maltreatment, alexithymia, impulsivity, and potentially related biological dysregulation in explaining aggression and negative mood states as a bio-psychological model of aggression and mood in schizophrenia.

Urgency Theory in the context of broader emotion theories: a conceptual review

Negative and positive urgency are two closely related personality traits that reflect the tendency for an individual to engage in maladaptive risk-taking in response to extreme negative and positive emotions, respectively. However, other prominent emotion theories describe how emotions contribute to adaptive, rather than maladaptive, decision-making. This conceptual review considers how Urgency Theory can be integrated with these broader existing emotion theories. We proceed as follows: a) briefly define what is meant by emotions in science and summarize basic human neuroscience underlying emotions; b) briefly describe select theories and research linking emotions to adaptive decision-making, including brain correlates of this effect; c) review Urgency Theory, including contrasting evidence that emotions lead to maladaptive outcomes and brain correlates of this effect; d) discuss how urgency can be integrated into theories that view emotions as both adaptive and maladaptive for decision-making; and e) propose future directions to advance research in this field. We identified four, not mutually exclusive, viable options to integrate Urgency Theory into existing theories: urgency as model-free emotion regulation, urgency as being driven by incidental emotions, urgency as a reflexive response to emotions, or urgency as an individual difference factor. We conclude that although all four options are viable, individual difference and model-free emotion regulation have the most empirical support to date. Importantly, the other two options are less well-researched. Direct tests comparing these integrations is necessary to determine the most accurate way to integrate urgency with existing emotion theories. We believe that this research can identify mechanisms underlying urgency and help inform future intervention and prevention development to reduce negative effects of urgency across numerous maladaptive behaviors and clinical disorders.

Emotion-related impulsivity and suicidal ideation and behavior in schizophrenia spectrum disorder: a pilot fMRI study

Introduction

Suicidal ideation and behavior (SIB) are serious problems in people with schizophrenia spectrum disorders (SSD). Nevertheless, relatively little is known about the circuitry underlying SIB in SSD. Recently, we showed that elevated emotional impulsivity (urgency) was associated with SIB in SSD. Here we examined brain activity in people with SSD and elevated SIB.

Methods

We tested 16 people with SSD who had low SIB and 14 people with high SIB on a task in which emotion regulation in response to affective pictures was implicitly manipulated using spoken sentences. Thus, there were neutral pictures preceded by neutral statements (NeutNeut condition), as well as negative pictures preceded by either negative (NegNeg) or neutral (NeutNeg) statements. After each picture, participants rated how unpleasant each picture was for them. The latter two conditions were compared to the NeutNeut condition. We compared the emotion-regulated condition (NeutNeg) to the unregulated condition (NeutNeut). Statistics were threshold using threshold free cluster enhancement (TFCE).

Results

People in the low SIB group showed higher activation in this contrast in medial frontal gyrus, right rostral anterior cingulate, bilateral superior frontal gyrus/DLPFC, and right middle cingulate gyrus, as well as right superior temporal gyrus.

Discussion

This study provides clues to the neural basis of SIB in SSD as well as underlying mechanisms.

Distal and proximal risk factors of problematic cannabis use associated with psychotic-like experiences

BACKGROUND

Problematic cannabis use is associated with endorsement of psychotic-like experiences (PLEs) in non-clinical samples. However, little is known in regard to predictors of this relationship, which may be relevant to prevention and intervention. In the present research, we investigate impulsivity and cannabis use motives as potential distal and proximal risk factors for PLEs using conditional process analysis.

METHODS

Using an online cross-sectional survey of N = 300 students, we assessed endorsement of PLEs using the Community Assessment of Psychic Experiences (CAPE), problematic cannabis use with the Cannabis Use Disorder Identification Test (CUDIT-R), motivations for using cannabis with the Substance Use Motives Measure, and impulsivity using the Urgency and Premeditation, Perseverance, Sensation Seeking, Positive Urgency Impulsive Behaviour Scale (UPPS-P).

RESULTS

All three subscales on the CAPE were associated with significantly higher scores on the CUDIT-R. Before and after covarying for sex, we found that higher CUDIT-R scores mediated the relations between lack of perseverance and negative urgency impulsivity with higher PLE symptoms. Furthermore, the indirect effect of cannabis use on the relationship between lack of perseverance and high negative PLE symptoms was only significant at high and moderate levels of depression-coping, but not at low depression-coping motives.

CONCLUSION

Impulsivity and depression-coping motives may be distal and proximal psychological risk factors for negative PLEs in the context of problematic cannabis use. Our findings are in line with the broader substance use and mental health literature and may be informative for cannabis use treatment targets.

Brain structural alterations associated with impulsiveness in male violent patients with schizophrenia

BACKGROUND

Violence in schizophrenia (SCZ) is a phenomenon associated with neurobiological factors. However, the neural mechanisms of violence in patients with SCZ are not yet sufficiently understood. Thus, this study aimed to explore the structural changes associated with the high risk of violence and its association with impulsiveness in patients with SCZ to reveal the possible neurobiological basis.

METHOD

The voxel-based morphometry approach and whole-brain analyses were used to measure the alteration of gray matter volume (GMV) for 45 schizophrenia patients with violence (VSC), 45 schizophrenia patients without violence (NSC), and 53 healthy controls (HC). Correlation analyses were used to examine the association of impulsiveness and brain regions associated with violence.

RESULTS

The results demonstrated reduced GMV in the right insula within the VSC group compared with the NSC group, and decreased GMV in the right temporal pole and left orbital part of superior frontal gyrus only in the VSC group compared to the HC group. Spearman correlation analyses further revealed a positive correlation between impulsiveness and GMV of the left superior temporal gyrus, bilateral insula and left medial orbital part of the superior frontal gyrus in the VSC group.

CONCLUSION

Our findings have provided further evidence for structural alterations in patients with SCZ who had engaged in severe violence, as well as the relationship between the specific brain alterations and impulsiveness. This work provides neural biomarkers and improves our insight into the neural underpinnings of violence in patients with SCZ.

Effectiveness of mindfulness-based intervention in schizophrenia: A meta-analysis of randomized controlled trials

Schizophrenia poses significant societal challenges, including interpersonal tension, an increased risk of suicide, and soaring medical costs. Although antipsychotics can prevent relapses, they often give rise to adverse effects and do not provide lasting relief. Mindfulness-based interventions (MBI) emerge as a hopeful avenue for improving outcomes. However, existing research and meta-analyses of the efficacy of MBI in schizophrenia remain limited. This study aimed to evaluate the efficacy of MBI as an adjunctive therapy for schizophrenia. Relevant randomized controlled trials (RCTs) were searched across PubMed, Embase, Web of Science, and Cochrane Library from inception dates up to January 12, 2023. Statistical analyses were conducted using Stata software (version 15.0) and Review Manager 5.4. The quality of the included RCTs was assessed using the revised Cochrane risk of bias tool. A total of 18 RCTs were included, with 675 patients and 704 health controls. Our meta-analysis revealed that MBI significantly improved psychosocial function, insight, and mindfulness in individuals with schizophrenia. The quality of the included RCTs had a low to moderate risk of bias. These findings suggest that MBI holds promise for improving the mental health of individuals with schizophrenia.

Associations between antipsychotics-induced weight gain and brain networks of impulsivity

Given the unpredictable rapid onset and ubiquitous consequences of weight gain induced by antipsychotics, there is a pressing need to get insights into the underlying processes at the brain system level that will allow stratification of "at risk" patients. The pathophysiological hypothesis at hand is focused on brain networks governing impulsivity that are modulated by neuro-inflammatory processes. To this aim, we investigated brain anatomy and functional connectivity in patients with early psychosis (median age: 23 years, IQR = 21-27) using anthropometric data and magnetic resonance imaging acquired one month to one year after initiation of AP medication. Our analyses included 19 patients with high and rapid weight gain (i.e., ≥5% from baseline weight after one month) and 23 patients with low weight gain (i.e., <5% from baseline weight after one month). We replicated our analyses in young (26 years, IQR = 22-33, N = 102) and middle-aged (56 years, IQR = 51-62, N = 875) healthy individuals from the general population. In early psychosis patients, higher weight gain was associated with poor impulse control score (β = 1.35; P = 0.03). Here, the observed brain differences comprised nodes of impulsivity networks - reduced frontal lobe grey matter volume (Pcorrected = 0.007) and higher striatal volume (Pcorrected = 0.048) paralleled by disruption of fronto-striatal functional connectivity (R = -0.32; P = 0.04). Weight gain was associated with the inflammatory biomarker plasminogen activator inhibitor-1 (β = 4.9, P = 0.002). There was no significant association between increased BMI or weight gain and brain anatomy characteristics in both cohorts of young and middle-aged healthy individuals. Our findings support the notion of weight gain in treated psychotic patients associated with poor impulse control, impulsivity-related brain networks and chronic inflammation.

Brain changes following mindfulness: Reduced caudate volume is associated with decreased positive urgency

Mindfulness training has been shown to improve psychological health and general well-being. However, it is unclear which brain and personality systems may be affected by this practice for improving adaptive behavior and quality of life. The present study explores the effects of a 5-week mindfulness-based intervention (MBI) at the neuroanatomical level and its relationship with dispositional mindfulness and impulsivity. Sixty-six risky drivers were quasi-randomly assigned to a mindfulness training group (MT) or a control group (N). Participants underwent magnetic resonance imaging and completed the Five Facet Mindfulness Questionnaire (FFMQ) and the UPPS-P impulsivity scale twice, at baseline and after receiving the MBI. We observed that MBI changes dispositional mindfulness in the non-reactivity and observing facets. Further, we observed that the magnitude of change in impulsivity was associated with the change in dispositional mindfulness. Whole-brain voxel-wise analysis revealed that the volume of the right caudate nucleus of the MT group (n = 27) showed a reduction compared to that of the control group (n = 33), which increased in terms of the pre-post measurement (MT=-1.76 mm3; N = 6.31 mm3). We also observed that reduced caudate nucleus volume correlated with decreased positive urgency in the MT group. Taken together, our results show that MBI improves the skills of observing and non-reactivity to inner experience, while producing changes in the structure of the caudate nucleus. These structural changes are associated with a reduction in impulsivity levels, decreasing the tendency to act rashly in situations that generate positive emotions and thus facilitating more adaptive behavior.

Emotion-related impulsivity is related to orbitofrontal cortical sulcation

Background

Emotion-related impulsivity (ERI) describes the trait-like tendency toward poor self-control when experiencing strong emotions. ERI has been shown to be elevated across psychiatric disorders and predictive of the onset and worsening of psychiatric syndromes. Recent work has correlated ERI scores with the neuroanatomy of the orbitofrontal cortex (OFC). Informed by a growing body of research indicating that the morphology of cortical folds (sulci) can produce insights into behavioral outcomes, the present study modeled the association between ERI and the sulcal morphology of OFC at a finer scale than previously conducted.

Methods

Analyses were conducted in a transdiagnostic sample of 118 individuals with a broad range of psychiatric syndromes. We first manually defined over 2000 sulci across the 118 participants. We then implemented a model-based LASSO regression to relate OFC sulcal morphology to ERI and test whether effects were specific to ERI as compared to non-emotion-related impulsivity.

Results

The LASSO regression revealed bilateral associations of ERI with the depth of eight OFC sulci. These effects were specific to ERI and were not observed in non-emotion-related impulsivity. In addition, we identified a new transverse component of the olfactory sulcus in every hemisphere that is dissociable from the longitudinal component based on anatomical features and correlation with behavior, which could serve as a new transdiagnostic biomarker.

Conclusions

The results of this data-driven investigation provide greater neuroanatomical and neurodevelopmental specificity on how OFC is related to ERI. As such, findings link neuroanatomical characteristics to a trait that is highly predictive of psychopathology.

Biomarkers for Cognitive Control, Response Inhibition, Aggressivity, Impulsivity, and Violence

Deficits in cognitive control contribute to behavioral impairments across neuropsychiatric disorders. Cognitive control is captured as a construct in the Research Domain Construct (RDoC) matrix and incorporate subdomains of goal selection, response selection, and performance monitoring. Relevant tasks for these subdomains include the "AX" version of the continuous performance task (goal selection) and the Go/NoGo and Stop-Signal reaction time tasks (response selection). Underlying mechanisms for these domains have been investigated intensively using fMRI and event-related potential (ERP) approaches, which provide candidate biomarkers for translational research. In RDoC, impulsive behaviors are provisionally assigned to the cognitive control/response selection construct, but other factors may also contribute. Impulsivity has gained increased importance over recent years due to its link to aggression and suicidality, which is mediated especially through the constructs of urgency and frustrative nonreward. These constructs, in turn, may be captured through scales such as the Urgency, (Lack of) Premeditation, (Lack of) Perseverance, and Sensation Seeking (UPPS-P) impulsivity scale and the Point Subtraction Aggression Paradigm (PSAP), respectively. At present, no validated biomarkers exist for either urgency or aggressivity. Potential directions for the development of predictive biomarkers for both targets are discussed.

Mediating effect of symptom severity on the relationship between aggression, impulsivity and quality of life outcomes among patients with schizophrenia and related psychoses

Aims

Aggression and impulsivity among individuals with schizophrenia have been associated with poor clinical outcomes including worsening of symptoms and substance abuse which have been linked to a lower quality of life (QoL). The current study aimed to look at the mediating effect of symptom severity on the relationship between aggression, impulsivity and QoL among outpatients with schizophrenia and related psychoses in a multi-ethnic Asian population.

Methods

Data (n = 397) were collected from outpatients seeking treatment at the Institute of Mental Health. The World Health Organization quality of life-BREF (WHOQOL-BREF) scale, the symptoms checklist-90 revised (SCL-90-R), Buss Perry aggression questionnaire (BPAQ), and the Barratt impulsiveness scales (BIS) were used to assess subjective well-being, symptom severity, aggression, and impulsivity, respectively. Mediation analysis was performed using the PROCESS macro to understand the mediating effect of symptom severity.

Results

Motor impulsivity (MI) was indirectly associated with both the physical and psychological health domains of QoL while self-control was indirectly associated with the physical, psychological, and environmental health QoL domains through increased symptom severity.

Conclusion

The significant indirect effect of symptom severity in our study highlights one potential pathway through which impulsivity impacts the QoL of individuals with schizophrenia and related psychoses. Elucidating other factors besides symptom severity that have an indirect effect on the QoL of individuals provides alternative approaches for treatment through which better clinical outcomes can be achieved.

Neurotransmission-related gene expression in the frontal pole is altered in subjects with bipolar disorder and schizophrenia

The frontal pole (Brodmann area 10, BA10) is the largest cytoarchitectonic region of the human cortex, performing complex integrative functions. BA10 undergoes intensive adolescent grey matter pruning prior to the age of onset for bipolar disorder (BP) and schizophrenia (SCHIZ), and its dysfunction is likely to underly aspects of their shared symptomology. In this study, we investigated the role of BA10 neurotransmission-related gene expression in BP and SCHIZ. We performed qPCR to measure the expression of 115 neurotransmission-related targets in control, BP, and SCHIZ postmortem samples (n = 72). We chose this method for its high sensitivity to detect low-level expression. We then strengthened our findings by performing a meta-analysis of publicly released BA10 microarray data (n = 101) and identified sources of convergence with our qPCR results. To improve interpretation, we leveraged the unusually large database of clinical metadata accompanying our samples to explore the relationship between BA10 gene expression, therapeutics, substances of abuse, and symptom profiles, and validated these findings with publicly available datasets. Using these convergent sources of evidence, we identified 20 neurotransmission-related genes that were differentially expressed in BP and SCHIZ in BA10. These results included a large diagnosis-related decrease in two important therapeutic targets with low levels of expression, HTR2B and DRD4, as well as other findings related to dopaminergic, GABAergic and astrocytic function. We also observed that therapeutics may produce a differential expression that opposes diagnosis effects. In contrast, substances of abuse showed similar effects on BA10 gene expression as BP and SCHIZ, potentially amplifying diagnosis-related dysregulation.

Neuroanatomical Correlates of Emotion-Related Impulsivity

BACKGROUND

Emotion-related impulsivity (ERI) refers to chronically poor self-control during periods of strong emotion. ERI robustly predicts psychiatric disorders and related problems, yet its neuroanatomical correlates are largely unknown. We tested whether local brain morphometry in targeted brain regions that integrate emotion and control could explain ERI severity.

METHODS

One hundred twenty-two adults (ages 18-55 years) with internalizing or externalizing psychopathology completed a structural magnetic resonance imaging (MRI) scan, the Three-Factor Impulsivity Index, and the Structured Clinical Interview for DSM-5. The Three-Factor Impulsivity Index measures two types of ERI and a third type of impulsivity not linked to emotion. Cortical reconstruction yielded cortical thickness and local gyrification measurements. We evaluated whether morphometry in the orbitofrontal cortex (OFC), insula, amygdala, and nucleus accumbens was associated with ERI severity. Hypotheses and analyses were preregistered.

RESULTS

Lower cortical gyrification in the right lateral OFC was associated with high ERI severity in a full, preregistered model. Separate examinations of local gyrification and cortical thickness also showed a positive association between gyrification in the left lateral OFC and ERI. An integrated measure of hemispheric imbalance in lateral OFC gyrification (right < left) correlated with ERI severity. These findings were specific to ERI and did not appear with non-emotion-related impulsivity.

CONCLUSIONS

Local gyrification in the lateral OFC is associated with ERI severity. The current findings fit with existing theories of OFC function, strengthen the connections between the transdiagnostic literature in psychiatry and neuroscience, and may guide future treatment development.

Functional dysconnectivity of anterior cingulate subregions in schizophrenia and psychotic and nonpsychotic bipolar disorder

Aberrant resting-state functional connectivity (FC) of anterior cingulate cortex (ACC) has been implicated in the pathophysiology of schizophrenia and bipolar disorder (BP). This study investigated the subregional FC of ACC across schizophrenia and psychotic (PBP) and nonpsychotic BP (NPBP) and the relationship between brain functional alterations and clinical manifestations. A total of 174 first-episode medication-naive patients with schizophrenia (FES), 80 patients with PBP, 77 patients with NPBP and 173 demographically matched healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. Brain-wide FC of ACC subregions was computed for each individual, and compared between the groups. General intelligence was evaluated using the short version of the Wechsler Adult Intelligence Scale. Relationships between FC and various clinical and cognitive variables were estimated using the skipped correlation. The FES, PBP and NPBP groups showed differing connectivity patterns in the left caudal, dorsal and perigenual ACC. Transdiagnostic dysconnectivity was found in the subregional ACC associated with cortical, limbic, striatal and cerebellar regions. Disorder-specific dysconnectivity in FES was identified between the left perigenual ACC and bilateral orbitofrontal cortex, and the left caudal ACC coupling with the default mode network (DMN) and visual processing region was correlated with psychotic symptoms. In the PBP group, FC between the left dorsal ACC and the right caudate was correlated with psychotic symptoms, and FC connected with the DMN was associated with affective symptoms. The current findings confirmed that subregional ACC dysconnectivity could be a key transdiagnostic feature and associated with differing clinical symptomology across schizophrenia and PBP.

Dysconnectivity between the anterior insula and the dorsal anterior cingulate cortex during an emotion go/nogo paradigm is associated with aggressive behaviors in male schizophrenia patients

This study aimed to investigate the association between past-reported violent/aggressive behaviors and brain functional connectivity in male patients suffering from schizophrenia using a task modeling the interaction between negative emotion processing and response inhibition. Forty-four male patients with schizophrenia and twenty-two healthy male controls performed an emotional go/no-go task using angry and neutral faces during a functional magnetic resonance imaging session. Generalized psycho-physiological interaction was conducted to explore task-based functional connectivity and a negative binomial regression was used to evaluate the relationship between neural alterations and violent/aggressive behaviors. Regions involved in response inhibition and emotion regulation, such as the anterior insula, dorsal anterior cingulate cortex (dACC) and dorsolateral prefrontal cortex (DLPFC), were used as seed regions. During emotion-related response inhibition, patients with schizophrenia displayed altered connectivity between the anterior insula and amygdala, the DLPFC and lateral orbitofrontal cortex (OFC), as well as the anterior insula and the dACC when compared to healthy individuals. The latter was negatively associated with aggressive behaviors in participants with schizophrenia (Wald χ² = 9.51; p < 0.05, p-FDR corrected). Our results highlight alterations in functional connectivity in brain regions involved in cognitive control and emotion processing which are associated with aggressive behaviors in schizophrenia.

Empirical support for a dual process model of the p-factor: Interaction effects between preschool executive control and preschool negative emotionality on general psychopathology

Recent work indicates that a general factor, often referred to as the p-factor, underlies nearly all forms of psychopathology. Although the criterion validity and utility of this general factor have been well supported, questions remain about the substantive meaning of the p-factor. The purpose of the present longitudinal study was to empirically test the hypothesis that the p-factor reflects dysregulation arising from a combination of high dispositional negative emotionality and low executive control. The current study examined preschool executive control, measured using a battery of 9 developmentally appropriate executive control tasks, as a moderator of the association between preschool negative emotionality and both concurrent and subsequent levels of general psychopathology in preschool and elementary school using a community sample (N = 497). Latent moderated structural equation models demonstrated that preschool executive control significantly moderated the associations between preschool negative emotionality and general psychopathology both in preschool and approximately 5 years later in elementary school. These results suggest that the general factor of psychopathology may reflect dysregulation arising from a tendency to experience high negative affect, without sufficient executive control to effectively down-regulate that affect. This work has important implications for identifying transdiagnostic targets for prevention and intervention efforts, as well as furthering understanding of the substantive meaning and construct validity of the general factor of psychopathology. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Risk for bipolar spectrum disorders associated with positive urgency and orbitofrontal cortical grey matter volume

Bipolar spectrum disorders (BSDs) are associated with reward hypersensitivity, impulsivity, and structural abnormalities within the brain's reward system. Using a behavioral high-risk study design based on reward sensitivity, this paper had two primary objectives: 1) investigate whether elevated positive urgency, the tendency to act rashly when experiencing extreme positive affect, is a risk for or correlate of BSDs, and 2) examine the nature of the relationship between positive urgency and grey matter volume in fronto-striatal reward regions, among individuals at differential risk for BSD. Young adults (ages 18-28) screened to be moderately reward sensitive (MReward; N = 42), highly reward sensitive (HReward; N = 48), or highly reward sensitive with a lifetime BSD (HReward + BSD; N = 32) completed a structural MRI scan and the positive urgency subscale of the UPPS-P scale. Positive urgency scores varied with BSD risk (MReward < HReward < HReward + BSD; ps≤0.05), and positive urgency interacted with BSD risk group in predicting lateral OFC volume (p <.001). Specifically, the MReward group showed a negative relationship between positive urgency and lateral OFC volume. By contrast, there was no relationship between positive urgency and lateral OFC grey matter volume among the HReward and HReward + BSD groups. The results suggest that heightened trait positive urgency is a pre-existing vulnerability for BSD that worsens with illness onset, and there is a distinct relationship between positive urgency and lateral OFC volume among individuals at high versus low risk for BSD. These findings have implications for understanding the expression and development of impulsivity in BSDs.

Gray matter reduction in bilateral insula mediating adverse psychiatric effects of body mass index in schizophrenia

BACKGROUND

Both schizophrenia (SZ) and overweight/obesity (OWB) have shown some structural alterations in similar brain regions. As higher body mass index (BMI) often contributes to worse psychiatric outcomes in SZ, this study was designed to examine the effects of OWB on gray matter volume (GMV) in patients with SZ.

METHODS

Two hundred fifty subjects were included and stratified into four groups (n = 69, SZ patients with OWB, SZ-OWB; n = 74, SZ patients with normal weight, SZ-NW; n = 54, healthy controls with OWB, HC-OWB; and n = 53, HC with NW, HC-NW). All participants were scanned using high-resolution T1-weighted sequence. The whole-brain voxel-based morphometry was applied to examine the GMV alterations, and a 2 × 2 full factorial analysis of variance was performed to identify the main effects of diagnosis (SZ vs HC), BMI (NW vs OWB) factors, and their interactions. Further, the post hoc analysis was conducted to compare the pairwise differences in GMV alterations.

RESULTS

The main effects of diagnosis were located in right hippocampus, bilateral insula, rectus, median cingulate/paracingulate gyri and thalamus (SZ < HC); while the main effects of BMI were displayed in right amygdala, left hippocampus, bilateral insula, left lingual gyrus, and right superior temporal gyrus (OWB < NW). There were no significant diagnosis-by-BMI interaction effects in the present study, but the results showed that both SZ and OWB were additively associated with lower GMV in bilateral insula. Moreover, mediation analyses revealed the indirect effect of BMI on negative symptom via GMV reduction in bilateral insula.

CONCLUSION

This study further supports that higher BMI is associated with lower GMV, which may increase the risk of unfavourable disease courses in SZ.

The age of violence: Mapping brain age in psychosis and psychopathy

Young chronological age is one of the strongest predictors for antisocial behaviour in the general population and for violent offending in individuals with psychotic disorders. An individual's age can be predicted with high accuracy using neuroimaging and machine-learning. The deviation between predicted and chronological age, i.e., brain age gap (BAG) has been suggested to reflect brain health, likely relating partly to neurodevelopmental and aging-related processes and specific disease mechanisms. Higher BAG has been demonstrated in patients with psychotic disorders. However, little is known about the brain-age in violent offenders with psychosis and the possible associations with psychopathy traits. We estimated brain-age in 782 male individuals using T1-weighted MRI scans. Three machine learning models (random forest, extreme gradient boosting with and without hyper parameter tuning) were first trained and tested on healthy controls (HC, n = 586). The obtained BAGs were compared between HC and age matched violent offenders with psychosis (PSY-V, n = 38), violent offenders without psychosis (NPV, n = 20) and non-violent psychosis patients (PSY-NV, n = 138). We ran additional comparisons between BAG of PSY-V and PSY-NV and associations with Positive and Negative Syndrome Scale (PANSS) total score as a measure of psychosis symptoms. Psychopathy traits in the violence groups were assessed with Psychopathy Checklist-revised (PCL-R) and investigated for associations with BAG. We found significantly higher BAG in PSY-V compared with HC (4.9 years, Cohen'sd = 0.87) and in PSY-NV compared with HC (2.7 years, d = 0.41). Total PCL-R scores were negatively associated with BAG in the violence groups (d = 1.17, p < 0.05). Additionally, there was a positive association between psychosis symptoms and BAG in the psychosis groups (d = 1.12, p < 0.05). While the significant BAG differences related to psychosis and not violence suggest larger BAG for psychosis, the negative associations between BAG and psychopathy suggest a complex interplay with psychopathy traits. This proof-of-concept application of brain age prediction in severe mental disorders with a history of violence and psychopathy traits should be tested and replicated in larger samples.

Feasibility and Utility of Different Approaches to Violence Risk Assessment for Young Adults Receiving Treatment for Early Psychosis

This pilot study examined violence risk assessment among a sample of young adults receiving treatment for early psychosis. In this study, thirty participants were assessed for violence risk at baseline. Participants completed follow-up assessments at 3, 6, 9 and 12 months to ascertain prevalence of violent behavior. Individuals were on average 24.1 years old (SD = 3.3 years) and predominantly male (n = 24, 80%). In this sample, six people (20%) reported engaging in violence during the study period. Individuals who engaged in violence had higher levels of negative urgency (t(28) = 2.21, p = 0.035) This study sought to establish the feasibility, acceptability, and clinical utility of violence risk assessment for clients in treatment for early psychosis. Overall, this study found that most individuals with early psychosis in this study (who are in treatment) were not at risk of violence. Findings suggest that violent behavior among young adults with early psychosis is associated with increased negative urgency.

Aberrant Functional Connectivity of the Orbitofrontal Cortex Is Associated With Excited Symptoms in First-Episode Drug-Naïve Patients With Schizophrenia

BACKGROUND

Schizophrenia (SZ) is associated with the highest disability rate among serious mental disorders. Excited symptoms are the core symptoms of SZ, which appear in the early stage, followed by other stages of the disease subsequently. These symptoms are destructive and more prone to violent attacks, posing a serious economic burden to the society. Abnormal spontaneous activity in the orbitofrontal cortex had been reported to be associated with excited symptoms in patients with SZ. However, whether the abnormality appears in first-episode drug-naïve patients with SZ has still remained elusive.

METHODS

A total of 56 first-episode drug-naïve patients with SZ and 27 healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI) and positive and negative syndrome scale (PANSS). First, differences in fractional amplitude of low-frequency fluctuations (fALFF) between first-episode drug-naïve patients with SZ and healthy controls were examined to identify cerebral regions exhibiting abnormal local spontaneous activity. Based on the fALFF results, the resting-state functional connectivity analysis was performed to determine changes in cerebral regions exhibiting abnormal local spontaneous activity. Finally, the correlation between abnormal functional connectivity and exciting symptoms was analyzed.

RESULTS

Compared with the healthy controls, first-episode drug-naïve patients with SZ showed a significant decrease in intrinsic activity in the bilateral precentral gyrus, bilateral postcentral gyrus, and the left orbitofrontal cortex. In addition, first-episode drug-naïve patients with SZ had significantly reduced functional connectivity values between the left orbitofrontal cortex and several cerebral regions, which were mainly distributed in the bilateral postcentral gyrus, the right middle frontal gyrus, bilateral paracentral lobules, the left precentral gyrus, and the right median cingulate. Further analyses showed that the functional connectivity between the left orbitofrontal cortex and the left postcentral gyrus, as well as bilateral paracentral lobules, was negatively correlated with excited symptoms in first-episode drug-naïve patients with SZ.

CONCLUSION

Our results indicated the important role of the left orbitofrontal cortex in first-episode drug-naïve patients with SZ and suggested that the abnormal spontaneous activity of the orbitofrontal cortex may be valuable to predict the occurrence of excited symptoms. These results may provide a new direction to explore the excited symptoms of SZ.

Sleep, stress and aggression: Meta-analyses investigating associations and causality

Prior research suggests that sleep is associated with increased subjective stress and aggression, but important questions remain about the typical magnitude of these relationships, as well as their potential moderators. We therefore conducted the first meta-analysis of this literature. Across 340 associational and experimental studies, significant associations were identified between sleep with both subjective stress (r = 0.307, p < .001) and aggression (r = 0.258, p < .001) in individuals from the general population, as well as between sleep with subjective stress (r = 0.425, p < .001) in individuals with sleep disorders. Experimental sleep restriction also led to increased subjective stress (g = 0.403, p = .017) and aggression (g = 0.330, p = .042). These findings suggest that poorer sleep is associated with - and leads to - heightened levels of subjective stress and aggression. These findings, and their implications, are discussed in relation to neurobiological literature, which highlights the complex interplay between metabolic activity in the brain, hormonal changes, and behavior.

Relationships between Diffusion Tensor Imaging and Resting State Functional Connectivity in Patients with Schizophrenia and Healthy Controls: A Preliminary Study

Schizophrenia is widely seen as a disorder of dysconnectivity. Neuroimaging studies have examined both structural and functional connectivity in the disorder, but these modalities have rarely been integrated directly. We scanned 29 patients with schizophrenia and 25 healthy control subjects, and we acquired resting state fMRI and diffusion tensor imaging. We used the Functional and Tractographic Connectivity Analysis Toolbox (FATCAT) to estimate functional and structural connectivity of the default mode network. Correlations between modalities were investigated, and multimodal connectivity scores (MCS) were created using principal component analysis. Of the 28 possible region pairs, 9 showed consistent (>80%) tracts across participants. Correlations between modalities were found among those with schizophrenia for the prefrontal cortex, posterior cingulate, and lateral temporal lobes, with frontal and parietal regions, consistent with frontotemporoparietal network involvement in the disorder. In patients, MCS correlated with several aspects of the Positive and Negative Syndrome Scale, with higher multimodal connectivity associated with outward-directed (externalizing) behavior and lower multimodal connectivity related to psychosis per se. In this preliminary sample, we found FATCAT to be a useful toolbox to directly integrate and examine connectivity between imaging modalities. A consideration of conjoint structural and functional connectivity can provide important information about the network mechanisms of schizophrenia.

Structural Deficits in the Frontotemporal Network Associated With Psychopathic Traits in Violent Offenders With Schizophrenia

People with schizophrenia (SZ) are at increased risk of violence compared to the general population. However, the neural mechanisms of violent behavior in patients with SZ are still unclear due to the heterogeneity of the diseased population. In this study, we aimed to examine the neural correlates of violent behavior in SZ and to determine whether the structural deficits were related to psychopathic traits. A total of 113 participants, including 31 SZ patients with violent behavior (vSZ), 39 SZ patients without violent behavior (nvSZ), and 43 healthy controls (HC), completed the T1-weighted magnetic resonance imaging (MRI) scan and were analyzed using voxel-based morphometry approach. The psychopathic traits were assessed using the Psychopathy Checklist: Screening Version (PCL:SV). The results showed decreased gray matter volume (GMV) in the vSZ group in the right temporal lobe and bilateral inferior frontal gyri compared to HCs; while reduced GMV in the inferior parietal lobe, parahippocampal and orbital frontal gyri was found in the nvSZ group compared with HCs. Correlation analyses showed that psychopathic traits were negatively associated with the GMV in the right superior temporal and left fusiform gyri in the vSZ group, indicating that psychopathic traits, as reflected by the score of antisocial factor, might be related to structural deficits in the temporal lobe, which led to a propensity to violent behavior in patients with SZ. Our findings suggest that violent behavior in patients with SZ might have a personality background associated with the frontotemporal network aberrance. In future studies, we need to take a closer look at psychopathic traits for better understanding of the mechanism of interpersonal violence in patients with SZ and to explore whether the imaging findings from this study can serve as a biomarker to predict future violent behaviors and community living.

Factors in the neurodevelopment of negative urgency: Findings from a community-dwelling sample

This study investigated neuroanatomic, genetic, cognitive, sociodemographic and emotional underpinnings of the Negative Urgency subscale of the Urgency, Premeditation, Perseverance, Sensation-Seeking and Positive Urgency Impulsive Behavior Scale in a healthy developmental sample. The goal of the investigation is to contribute to the harmonisation of behavioural, brain and neurogenetic aspects of behavioural self-control. Three domains - (1) Demographic, developmental, psychiatric and cognitive ability; (2) Regional brain volumes (neurobiological); and (3) Genetic variability (single nucleotide polymorphisms) - were examined, and models with relevant predictor variables were selected. Least absolute shrinkage and selection operator and best subset regressions were used to identify sparse models predicting negative urgency scores, which revealed that variables related to emotional regulation and right cingulate volume, as well as single nucleotide polymorphisms in CADM2 and SLC6A4, were associated with negative urgency. Our results contribute to the construct and criterion validity of negative urgency and support the hypothesis that negative urgency is a result of a complex array of influences across domains whose integration furthers developmental psychopathology research.

The Link Between Cannabis Use and Violent Behavior in the Early Phase of Psychosis: The Potential Role of Impulsivity

INTRODUCTION

Recently, the literature has shown that Cannabis Use (CU) was a risk factor for Violent Behavior (VB) in patients with psychosis, and those in the early phase of psychosis (EPP). These findings are relevant because of the high prevalence of CU in this EPP, and the potential for prevention during this phase of illness. However, there is still a lack of clear explanations, supported by empirical evidence, about what underlies the link between CU and VB against other.

METHOD

This viewpoint reviews the scientific literature on the link between CU and VB, and the involvement of impulsivity in this relationship. This last point will be addressed at clinical and neurobiological levels.

RESULTS

Recent studies confirmed that CU is particularly high in the EPP, and is a risk factor for VB in the EPP and schizophrenia. Studies have also shown that impulsivity is a risk factor for VB in psychosis, is associated with CU, and may mediate the link between CU and VB. Research suggests a neurobiological mechanism, as CU affects the structures and function of frontal areas, known to play a role in impulsive behavior.

CONCLUSION

Scientific evidence support the hypothesis of an involvement of impulsivity as a variable that could mediate the link between CU and aggression, particularly, when CU has an early onset. However, this hypothesis should be confirmed with longitudinal studies and by taking into account confounding factors. The studies highlight the relevance of early prevention in the EPP, in addition to interventions focusing on psychotic disorders.

Improving Between-Group Effect Size for Multi-Site Functional Connectivity Data via Site-Wise De-Meaning

Background: Multi-site functional MRI (fMRI) databases are becoming increasingly prevalent in the study of neurodevelopmental and psychiatric disorders. However, multi-site databases are known to introduce site effects that may confound neurobiological and measures such as functional connectivity (FC). Although studies have been conducted to mitigate site effects, these methods often result in reduced effect size in FC comparisons between controls and patients.

Methods: We present a site-wise de-meaning (SWD) strategy in multi-site FC analysis and compare its performance with two common site-effect mitigation methods, i.e., generalized linear model (GLM) and Combining Batches (ComBat) Harmonization. For SWD, after FC was calculated and Fisher z-transformed, the site-wise FC mean was removed from each subject before group-level statistical analysis. The above methods were tested on two multi-site psychiatric consortiums [Autism Brain Imaging Data Exchange (ABIDE) and Bipolar and Schizophrenia Network on Intermediate Phenotypes (B-SNIP)]. Preservation of consistent FC alterations in patients were evaluated for each method through the effect sizes (Hedge’s g) of patients vs. controls.

Results: For the B-SNIP dataset, SWD improved the effect size between schizophrenic and control subjects by 4.5–7.9%, while GLM and ComBat decreased the effect size by 22.5–42.6%. For the ABIDE dataset, SWD improved the effect size between autistic and control subjects by 2.9–5.3%, while GLM and ComBat decreased the effect size by up to 11.4%.

Conclusion: Compared to the original data and commonly used methods, the SWD method demonstrated superior performance in preserving the effect size in FC features associated with disorders.

White matter correlates of impulsivity in frontal lobe and their associations with treatment response in first-episode schizophrenia

BACKGROUND

It is known that increased impulsivity in schizophrenia patients causes poor treatment outcomes by increasing cost, stigma, hospitalization, treatment challenge, and physical harm. Dysfunction in the prefrontal cortex appears to be involved in the impulsivity associated with schizophrenia; nonetheless, there is a dearth of research on specific white matter alterations in the prefrontal cortex related to impulsivity.

METHODS

We enrolled in the present study 119 first-episode schizophrenia patients. We measured their symptom severity at baseline and after eight weeks of treatment, using the positive and negative syndrome scale. We performed neuroimaging analysis using the Tract-Based Spatial Statistics program and by specifying the prefrontal white matter as a region of interest.

RESULTS

In voxel-wise correlational analysis, we observed white matter regions showing significant positive correlations with poor impulse control scores, in both the right dorsolateral prefrontal cortex and the right frontal pole region. The fractional anisotropy values of these areas correlated positively with symptom severity at baseline. Moreover, after eight weeks, treatment non responders showed significantly higher fractional anisotropy values in the same areas.

CONCLUSIONS

The results of the present study suggest that white matter tracts in the right dorsolateral prefrontal cortex and the right frontal pole may underlie dysfunctional impulse control and could be potential predictive markers for short-term treatment in patients with first-episode schizophrenia.

Interactive effects of DRD2 rs6277 polymorphism, environment and sex on impulsivity in a population-representative study

Previous research has shown that dopaminergic dysregulation and early life stress interact to impact on aspects of impulse control. This study aimed to explore the potentially interactive effects of the rs6277 polymorphism of the dopamine D2 receptor gene (DRD2), stressful or supportive environment and sex on behavioural and self-reported measures of impulsivity, as well as alcohol use - a condition characterised by a deficit in impulse control. The sample consisted of the younger cohort (n = 583) of the longitudinal Estonian Children Personality, Behaviour and Health Study. The results showed that the CC homozygotes (suggested to have decreased striatal D2 receptor availability) who had experienced stressful life events (SLE) or maltreatment in the family prior to age 15 showed higher self-reported maladaptive impulsivity at age 15. The genotype-SLE interaction and further association with sex was also evident in the frequency of alcohol use at age 15. Lack of warmth in the family contributed to significantly higher levels of thoughtlessness and more frequent alcohol use in CC carriers at age 25, whereas family support was associated with lower thoughtlessness scores in CC males, which may suggest a protective effect of supportive family environment in this group. Together the findings suggest that DRD2 rs6277 polymorphism, in interaction with environmental factors experienced in childhood and youth may affect facets of impulsivity. Future work should aim to further clarify the sex and age-specific effects of stressful and supportive environment on the development of neuronal systems that are compromised in disorders characterised by deficits in impulse control.

Validation of an emotional stop-signal task to probe individual differences in emotional response inhibition: Relationships with positive and negative urgency

Performance on an emotional stop-signal task designed to assess emotional response inhibition has been associated with Negative Urgency and psychopathology, particularly self-injurious behaviors. Indeed, difficulty inhibiting prepotent negative responses to aversive stimuli on the emotional stop-signal task (i.e. poor negative emotional response inhibition) partially explains the association between Negative Urgency and non-suicidal self-injury. Here, we combine existing data sets from clinical (hospitalised psychiatric inpatients) and non-clinical (community/student participants) samples aged 18-65 years (N = 450) to examine the psychometric properties of this behavioural task and evaluate hypotheses that emotional stop-signal task metrics relate to distinct impulsive traits among participants who also completed the UPPS-P (n = 223). We specifically predicted associations between worse negative emotional response inhibition (i.e. commission errors during stop-signal trials representing negative reactions to unpleasant images) and Negative Urgency, whereas commission errors to positive stimuli - reflecting worse positive emotional response inhibition - would relate to Positive Urgency. Results support the emotional stop-signal task's convergent and discriminant validity: as hypothesised, poor negative emotional response inhibition was specifically associated with Negative Urgency and no other impulsive traits on the UPPS-P. However, we did not find the hypothesised association between positive emotional response inhibition and Positive Urgency. Correlations between emotional stop-signal task performance and self-report measures were the modest, similar to other behavioural tasks. Participants who completed the emotional stop-signal task twice (n = 61) additionally provide preliminary evidence for test-retest reliability. Together, findings suggest adequate reliability and validity of the emotional stop-signal task to derive candidate behavioural markers of neurocognitive functioning associated with Negative Urgency and psychopathology.

Personality Traits in Individuals with the Dual Diagnosis of Psychosis and Substance Use Disorders: A Comprehensive Review and Meta-Analysis

Substance abuse comorbidity is highly prevalent and is linked to detrimental outcomes in individuals with psychotic disorder, but the role of personality traits as the underlying mechanism is being increasingly underscored. This study aimed to profile temperamental risks of comorbid substance use disorder in psychotic disorders by performing meta-analyses on personality trait differences between psychotic disorders with comorbidity (dual diagnosis; DD) and without it (psychotic disorders; PSD). Methods: A systematic review of English articles using PubMed, MEDLINE, Scopus, Google Scholar, and ProQuest Dissertation and Theses. Only original empirical studies including participants with diagnosis of psychotic disorders based on structured diagnostic interviews, with and without substance use disorder evaluated with reliable and valid tests were included. Articles were independently extracted by two authors using predefined data fields, including study quality indicators. All pooled analyses were based on random-effect models. Thirteen studies (N = 885) met our inclusion criteria. All effect-size estimates were calculated based on means and standard deviations of included measures. Separate effect size estimates were obtained for four traits in the UPPS model (negative urgency, low premeditation, low perseverance, sensation seeking), four traits in the HS model (unconscientious disinhibition, negative affect, disagreeable disinhibition, positive affect) and trait anhedonia. Results: Negative urgency (four studies with 262 participants; ES = 0.59; 95% confidence interval [CI] [0.34, 0.84]), low premeditation (five studies with 349 participants; ES = 0.60; 95% CI [0.39, 0.80]), sensation seeking (seven studies with 550 participants; ES = 0.63; 95% CI [0.17, 1.09]) and unconscientious disinhibition (five studies with 291 participants; ES = 0.36; 95% CI [0.13, 0.59]) were elevated in DD than PSD. Heterogeneity of sensation seeking was significant (I² = 86.2%). Conclusions: The findings of the current meta-analysis highlight a unique profile of impulsive and externalizing trait personality domains pertaining to DD. The study emphasizes the importance of emotion regulation interventions targeting impulsivity or negative affect (i.e. negative urgency, low premeditation) in substance abuse comorbidity patients.

Neuroanatomical correlates of impulsive traits in children aged 9 to 10

Impulsivity refers to a set of traits that are generally negatively related to critical domains of adaptive functioning and are core features of numerous psychiatric disorders. The current study examined the gray and white matter correlates of five impulsive traits measured using an abbreviated version of the UPPS-P (Urgency, (lack of) Premeditation, (lack of) Perseverance, Sensation-Seeking, Positive Urgency) impulsivity scale in children aged 9 to 10 (N = 11,052) from the Adolescent Brain and Cognitive Development (ABCD) study. Linear mixed effect models and elastic net regression were used to examine features of regional gray matter and white matter tractography most associated with each UPPS-P scale; intraclass correlations were computed to examine the similarity of the neuroanatomical correlates among the scales. Positive Urgency showed the most robust association with neuroanatomy, with similar but less robust associations found for Negative Urgency. Perseverance showed little association with neuroanatomy. Premeditation and Sensation Seeking showed intermediate associations with neuroanatomy. Critical regions across measures include the dorsolateral prefrontal cortex, lateral temporal cortex, and orbitofrontal cortex; critical tracts included the superior longitudinal fasciculus and inferior fronto-occipital fasciculus. Negative Urgency and Positive Urgency showed the greatest neuroanatomical similarity. Some UPPS-P traits share neuroanatomical correlates, while others have distinct correlates or essentially no relation to neuroanatomy. Neuroanatomy tended to account for relatively little variance in UPPS-P traits (i.e., Model R2 < 1%) and effects were spread throughout the brain, highlighting the importance of well powered samples. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Pathways to aggression and violence in psychosis without longstanding antisocial behavior: A review and proposed psychosocial model for integrative clinical interventions

There is a need for a clearer understanding of the factors associated with increased risk of aggression and violence (AV) among people with psychosis and other severe mental illness (SMI) to guide effective prevention and intervention. The current article (1) reviews the literature regarding psychosocial factors associated with AV among individuals with psychosis and other SMI who do not have longstanding antisocial behaviors, (2) proposes an integrative psychosocial model of AV that can be practically applied, and (3) proposes appropriate evidence-based clinical interventions to reduce AV and facilitate recovery. We propose that increased risk for AV among people with psychosis is driven by anger, which is affected by a range of factors including victimization and situational stressors, social rejection or experiences of discrimination, anxious arousal, and hostile attribution bias related to psychosis. The cumulative effect of these systems is exacerbated by co-occurring substance misuse and increased impulsivity, particularly negative urgency. In consideration of the current psychosocial model and existing evidence-based interventions for AV in individuals with psychosis, we propose that trauma-informed interventions that integrate skills training in emotion regulation, social and interpersonal situations, cognitive restructuring and remediation, and modified prolonged exposure may demonstrate the most promise for this population.

Relationship of negative urgency to cingulo-insular and cortico-striatal resting state functional connectivity in tobacco use

Negative urgency, defined as a tendency to act rashly under extreme negative emotion, is strongly associated with tobacco use. Despite the robust evidence linking negative urgency and tobacco use and accumulating evidence suggesting that localized, segregated brain regions such as the nucleus accumbens (NAcc), insula, and amygdala are related to negative urgency, resting state functional connectivity (rsFC) of negative urgency in tobacco use has not yet been examined. This study included 34 daily tobacco users and 62 non-users matched on age, gender, race/ethnicity, and lifetime psychiatric diagnosis from a publicly available neuroimaging dataset collected by the Nathan Kline Institute-Rockland Project. Using the bilateral NAcc, insula, and amygdala as seed regions, seed-based rsFC analyses were conducted on the whole brain. In the whole sample, negative urgency was positively correlated with rsFC between the left insula and right dorsal anterior cingulate cortex (dACC). Compared to non-users, tobacco users had a stronger rsFC strength between the right amygdala and right middle temporal gyrus. In tobacco users, negative urgency was negatively associated with rsFC between the left NAcc and right dACC and between the left NAcc and right dorsolateral prefrontal cortex; these relationships were positive in non-users. Identifying functional connectivity implicated in negative urgency and tobacco use is the crucial first step to design and test pharmacological and physiological interventions to reduce negative urgency related tobacco use.

Development of a brief online intervention to address aggression in the context of emotion-related impulsivity: Evidence from a wait-list controlled trial

Trait-like tendencies to respond impulsively to emotion, labelled emotion-related impulsivity, are robustly related to aggression. We developed and tested an online intervention to address emotion-related impulsivity and aggression. The 6-session intervention focused on behavioral techniques shown to decrease arousal and aggression, supplemented with implementation intentions and smartphone prompts to facilitate skills transfer into daily life. First, we piloted the intervention in-person with 4 people. Then, 235 participants were randomly assigned to take the online intervention immediately or after a wait-list period; those in the waitlist were then invited to take part in the intervention. Participants completed the self-rated Feelings Trigger Action Scale to assess emotion-related impulsivity, the interview-based Modified Overt Aggression Scale and the self-rated Buss Perry Aggression Questionnaire. Participants who took part in the treatment completed daily anger logs. Attrition, as with other online programs, was high; however, treatment completers reported high satisfaction, and outcomes changed more rapidly during treatment than waitlist across all key outcome indices. In analyses including all participants who took part in the treatment (immediate or delayed), we observed moderate-to-large treatment gains, which were maintained as of the 3-month follow-up assessment. This work supports the usefulness of an intervention for addressing emotion-related impulsivity and aggression.

Network-level mechanisms underlying effects of transcranial direct current stimulation (tDCS) on visuomotor learning

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation approach in which low level currents are administered over the scalp to influence underlying brain function. Prevailing theories of tDCS focus on modulation of excitation-inhibition balance at the local stimulation location. However, network level effects are reported as well, and appear to depend upon differential underlying mechanisms. Here, we evaluated potential network-level effects of tDCS during the Serial Reaction Time Task (SRTT) using convergent EEG- and fMRI-based connectivity approaches. Motor learning manifested as a significant (p <.0001) shift from slow to fast responses and corresponded to a significant increase in beta-coherence (p <.0001) and fMRI connectivity (p <.01) particularly within the visual-motor pathway. Differential patterns of tDCS effect were observed within different parametric task versions, consistent with network models. Overall, these findings demonstrate objective physiological effects of tDCS at the network level that result in effective behavioral modulation when tDCS parameters are matched to network-level requirements of the underlying task.

Individual-specific functional connectivity markers track dimensional and categorical features of psychotic illness

Neuroimaging studies of psychotic disorders have demonstrated abnormalities in structural and functional connectivity involving widespread brain networks. However, these group-level observations have failed to yield any biomarkers that can provide confirmatory evidence of a patient's current symptoms, predict future symptoms, or predict a treatment response. Lack of precision in both neuroanatomical and clinical boundaries have likely contributed to the inability of even well-powered studies to resolve these key relationships. Here, we employed a novel approach to defining individual-specific functional connectivity in 158 patients diagnosed with schizophrenia (n = 49), schizoaffective disorder (n = 37), or bipolar disorder with psychosis (n = 72), and identified neuroimaging features that track psychotic symptoms in a dimension- or disorder-specific fashion. Using individually specified functional connectivity, we were able to estimate positive, negative, and manic symptoms that showed correlations ranging from r = 0.35 to r = 0.51 with the observed symptom scores. Comparing optimized estimation models among schizophrenia spectrum patients, positive and negative symptoms were associated with largely non-overlapping sets of cortical connections. Comparing between schizophrenia spectrum and bipolar disorder patients, the models for positive symptoms were largely non-overlapping between the two disorder classes. Finally, models derived using conventional region definition strategies performed at chance levels for most symptom domains. Individual-specific functional connectivity analyses revealed important new distinctions among cortical circuits responsible for the positive and negative symptoms, as well as key new information about how circuits underlying symptom expressions may vary depending on the underlying etiology and illness syndrome from which they manifest.

Aggressiveness is associated with excitement on the five-factor model of the positive and negative syndrome scale and prefrontal function in patients with stable schizophrenia

Aggressiveness is a clinical concern in the stable phase of schizophrenia, as well as in the acute phase. The factors that affect aggressiveness during the stable phase remain unclear. This study investigated factors associated with aggressiveness in patients with stable schizophrenia. Sixty-six patients with schizophrenia who were in the stable phase without acute exacerbation were assessed for aggressiveness using the Buss-Perry Aggression Questionnaire; impulsivity using the Barratt Impulsiveness Scale Version 11, psychotic symptoms using the five-factor model of the Positive and Negative Syndrome Scale (PANSS) including positive symptoms, negative symptoms, disorganization, excitement, and emotional distress; and prefrontal hemodynamic responses using near-infrared spectroscopy. Multivariate regression analyses showed that the excitement factor of the PANSS five-factor model, which comprised four PANSS items (poor impulse control, hyperactivity, hostility, and uncooperativeness), and delayed prefrontal hemodynamic responses were associated with elevated aggressiveness. These findings suggest that in patients with stable schizophrenia, excitement symptoms and prefrontal dysfunction are associated with elevated aggressiveness. Furthermore, the impact of impulsive traits on aggressiveness is less relevant. Our results shed light on a specific aspect of aggressiveness in patients with stable schizophrenia and may indicate factors to consider in the clinical setting.

Effect of brexpiprazole on control of impulsivity in schizophrenia: A randomized functional magnetic resonance imaging study

Impulsivity in schizophrenia is a risk factor for suicide, drug abuse, and other risk-taking behaviors. This exploratory, multicenter, randomized, double-blind, functional magnetic resonance imaging (fMRI) study assessed the effects of brexpiprazole on brain regions that control impulsive behavior. Thirty-eight outpatients with stable schizophrenia and impulsivity symptoms were randomized to 6 weeks of brexpiprazole 2 or 4 mg/day. The prespecified outcome measure was blood oxygen-level dependent (BOLD) activation in the right ventrolateral prefrontal cortex (VLPFC) during performance of tasks associated with inhibition/control of impulsivity: the go/no-go task and stop-signal task. Secondary objectives evaluated the efficacy, safety and tolerability of brexpiprazole. Over 6 weeks, patients receiving brexpiprazole had no statistically significant change in right VLPFC BOLD activation during the go/no-go task, but showed a significant decrease in right VLPFC BOLD activation during the stop-signal task. Brexpiprazole was also associated with significantly improved stop-signal reaction time (SSRT). No worsening of psychiatric symptoms, functioning, or impulsivity occurred in these patients. No unexpected safety or tolerability concerns were identified. In conclusion, brexpiprazole treatment among patients with schizophrenia and impulsivity was associated with decreased right VLPFC activation and decreased SSRT, supportive of a benefit of brexpiprazole on inhibition-related brain activation and behavior. ClinicalTrials.gov identifier: NCT02194933.