Cortical organization of inhibition-related functions and modulation by psychopathology

Disentangling effects of remote mild traumatic brain injury characteristics and posttraumatic stress on processing speed and executive function in veterans

Mild traumatic brain injury (mTBI) and posttraumatic stress are prevalent in military service members and share objective and subjective cognitive symptoms, complicating recovery. We investigated the effects of remote mTBI characteristics and current posttraumatic stress symptoms on neuropsychological performance in 152 veterans with a history of remote mTBI and current cognitive concerns. Participants completed clinical neuropsychological evaluations within a Veterans Affairs Level-II TBI/Polytrauma outpatient clinic (i.e. tertiary trauma care center for US military veterans outside of a research or teaching hospital setting). Archival data analysis of mTBI injury characteristics, clinical diagnoses, scores on the Posttraumatic Stress Disorder Checklist-Military Version (PCL-M) and performance on tests of processing speed, attention and executive function was conducted. Hierarchical linear regression demonstrated that elevated PCL-M scores were associated with slower performance on trail making test (TMT) Parts A and B (p < .016). PCL-M symptoms moderated the effect of alteration of consciousness (AOC) on TMT performance, with endorsement of AOC associated with better performance, but only when PCL-M scores were high (p < .005). Follow-up mediation analyses demonstrated that PCL-M score fully mediated the relationship between AOC and TMT-A performance and partially mediated the relationship between AOC and TMT-B performance. Post-hoc analyses meant to separate the impact of processing speed on TMT-B were all non-significant. Remote mTBI characteristics, specifically AOC, were not associated with decrements in cognitive performance. Posttraumatic symptoms were associated with worse processing speed, suggesting that psychological distress and psychopathology are contributing factors in understanding and treating persistent cognitive distress following remote mTBI.

Event-related EEG synchronization and desynchronization in patients with obsessive-compulsive disorder

Symptoms in patients with obsessive-compulsive disorder (OCD) are associated with impairment in cognitive control, attention, and action inhibition. We investigated OCD group differences relative to healthy subjects in terms of event-related alpha and beta range synchronization (ERS) and desynchronization (ERD) during a visually cued Go/NoGo task. Subjects were 62 OCD patients and 296 healthy controls (HC). The OCD group in comparison with HC, showed a changed value of alpha/beta oscillatory power over the central cortex, in particular, an increase in the alpha/beta ERD over the central-parietal cortex during the interstimulus interval (Cue condition) as well as changes in the postmovement beta synchronization topography and frequency. Over the frontal cortex, the OCD group showed an increase in magnitude of the beta ERS in NoGo condition. Within the parietal-occipital ERS/ERD modulations, the OCD group showed an increase in the alpha/beta ERD over the parietal cortex after the presentation of the visual stimuli as well as a decrease in the beta ERD over the occipital cortex after the presentation of the Cue and Go stimuli. The specific properties in the ERS/ERD patterns observed in the OCD group may reflect high involvement of the frontal and central cortex in action preparation and action inhibition processes and, possibly, in maintaining the motor program, which might be a result of the dysfunction of the cortico-striato-thalamo-cortical circuits involving prefrontal cortex. The data about enhanced involvement of the parietal cortex in the evaluation of the visual stimuli are in line with the assumption about overfocused attention in OCD.

The dimensional structure of internalizing psychopathology: Relation to diagnostic categories

Recent approaches aim to represent the dimensional structure of psychopathology, but relatively little research has rigorously tested sub-dimensions within internalizing psychopathology. This study tests pre-registered models of the dimensional structure of internalizing psychopathology, and their relations with current and lifetime depressive and anxiety disorders diagnostic data, in adult samples harmonized across three sites (n=427). Across S-1 bifactor and hierarchical models, we found converging evidence for both general and specific internalizing dimensions. Depression, generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic attacks were all associated with a general internalizing factor that we posit primarily represents motivational anhedonia. GAD was also associated with a specific anxious apprehension factor, and SAD with specific anxious apprehension and low positive affect factors. We suggest that dimensional approaches capturing shared and specific internalizing symptom facets more accurately describe the structure of internalizing psychopathology and provide useful alternatives to categorical diagnoses to advance clinical science.

Application of Machine Learning to Diagnostics of Schizophrenia Patients Based on Event-Related Potentials

Schizophrenia is a major psychiatric disorder that significantly reduces the quality of life. Early treatment is extremely important in order to mitigate the long-term negative effects. In this paper, a machine learning based diagnostics of schizophrenia was designed. Classification models were applied to the event-related potentials (ERPs) of patients and healthy subjects performing the visual cued Go/NoGo task. The sample consisted of 200 adult individuals ranging in age from 18 to 50 years. In order to apply the machine learning models, various features were extracted from the ERPs. The process of feature extraction was parametrized through a special procedure and the parameters of this procedure were selected through a grid-search technique along with the model hyperparameters. Feature extraction was followed by sequential feature selection transformation in order to prevent overfitting and reduce the computational complexity. Various models were trained on the resulting feature set. The best model was support vector machines with a sensitivity and specificity of 91% and 90.8%, respectively.

Association between ADHD symptoms and inhibition-related brain activity using functional near-infrared spectroscopy (fNIRS)

Attention deficit hyperactivity disorder (ADHD) is associated with deficits in inhibitory functions including interference control, inhibition of prepotent/automatic responses and suppression of already initiated responses. This study used functional near-infrared spectroscopy (fNIRS) to investigate the neural basis of these three forms of inhibition assessed by a recently developed behavioral protocol combining the Stroop-matching/stop-signal task in twenty-five young adults with inattention, impulsivity and/or hyperactivity symptoms. The severity of ADHD symptoms was measured using the Adult ADHD Self-Report Scale (ASRS). The concentration of oxygenated hemoglobin (HbO) was assessed in the dorsolateral prefrontal cortex (DLPFC), inferior frontal gyrus (IFG) and temporoparietal regions (TP) during the Stroop-matching/stop-signal task. Correlations yielded significant associations between ASRS scores and HbO concentration in frontal regions during blocks with stop-signal tasks, namely the right IFG, the left DLPFC and the left IFG. This study revealed that different types of inhibition involve unique frontal and temporoparietal activities and linked frontal dysfunction during the suppression of ongoing responses to the severity of ADHD symptoms.

Predictive utility of symptom measures in classifying anxiety and depression: A machine-learning approach

Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are highly prevalent, co-occurring disorders with significant symptom overlap, posing challenges in accurately distinguishing and diagnosing these disorders. The tripartite model proposes that anxious arousal is specific to anxiety and anhedonia is specific to depression, though anxious apprehension may play a greater role in GAD than anxious arousal. The present study tested the efficacy of the Mood and Anxiety Symptom Questionnaire anhedonic depression (MASQ-AD) and anxious arousal (MASQ-AA) scales and the Penn State Worry Questionnaire (PSWQ) in identifying lifetime or current MDD, current major depressive episode (MDE), and GAD using binary support vector machine learning algorithms in an adult sample (n = 150). The PSWQ and MASQ-AD demonstrated predictive utility in screening for and identification of GAD and current MDE respectively, with the MASQ-AD eight-item subscale outperforming the MASQ-AD 14-item subscale. The MASQ-AA did not predict MDD, current MDE, or GAD, and the MASQ-AD did not predict current or lifetime MDD. The PSWQ and MASQ-AD are efficient and accurate screening tools for GAD and current MDE. Results support the tripartite model in that anhedonia is unique to depression, but inclusion of anxious apprehension as a separate dimension of anxiety is warranted.

Specificity of anhedonic alterations in resting-state network connectivity and structure: A transdiagnostic approach

Anhedonia is a prominent characteristic of depression and related pathology that is associated with a prolonged course of mood disturbance and treatment resistance. However, the neurobiological mechanisms of anhedonia are poorly understood as few studies have disentangled the specific effects of anhedonia from other co-occurring symptoms. Here, we take a transdiagnostic, dimensional approach to distinguish anhedonia alterations from other internalizing symptoms on intrinsic functional brain circuits. 53 adults with varying degrees of anxiety and/or depression completed resting-state fMRI. Neural networks were identified through independent components analysis. Dual regression was used to characterize within-network functional connectivity alterations associated with individual differences in anhedonia. Modulation of between-network functional connectivity by anhedonia was tested using region-of-interest to region-of-interest correlational analyses. Anhedonia was associated with visual network hyperconnectivity and expansion of the visual, dorsal attention, and default networks. Additionally, anhedonia was associated with decreased between-network connectivity among default, salience, dorsal attention, somatomotor, and visual networks. Findings suggest that anhedonia is associated with aberrant connectivity and structural alterations in resting-state networks that contribute to impairments in reward learning, low motivation, and negativity bias characteristic of depression. Results reveal dissociable effects of anhedonia on resting-state network dynamics, characterizing possible neurocircuit mechanisms for intervention.

Differential Patterns of Delayed Emotion Circuit Maturation in Abused Girls With and Without Internalizing Psychopathology

OBJECTIVE

Childhood abuse represents one of the most potent risk factors for developing psychopathology, especially in females. Evidence suggests that exposure to early-life adversity may be related to advanced maturation of emotion processing neural circuits. However, it remains unknown whether abuse is related to early circuit maturation and whether maturation patterns depend on the presence of psychopathology.

METHODS

A multisite sample of 234 girls (ages 8-18 years) completed clinical assessment, maltreatment histories, and high-resolution T1-weighted structural MRI. Girls were stratified by abuse history and internalizing disorder diagnosis into typically developing (no abuse/no diagnosis), resilient (abuse/no diagnosis), and susceptible (abuse/current diagnosis) groups. Machine learning models of normative brain development were aggregated in a stacked generalization framework trained to predict chronological age using gray matter volume in whole-brain, emotion, and language circuit parcellations. Brain age gap estimations (BrainAGEs; predicted age minus true chronological age) were calculated as indices of relative circuit maturation.

RESULTS

Childhood abuse was related to reduced BrainAGE (delayed maturation) specific to emotion circuits. Delayed emotion circuit BrainAGE was further related to increased hyperarousal symptoms. Childhood physical neglect was associated with increased whole-brain BrainAGE (advanced maturation). Neural contributors to emotion circuit BrainAGE differed in girls with and without an internalizing diagnosis, especially in the lateral prefrontal, parietal, and insular cortices and the hippocampus.

CONCLUSIONS

Abuse exposure in girls is associated with a delayed structural maturation pattern specific to emotion circuitry, a potentially adaptive mechanism enhancing threat generalization. Physical neglect, on the other hand, is associated with a broader brain-wide pattern of advanced structural maturation. The differential influence of fronto-parietal cortices and the hippocampus on emotion circuit maturity in resilient girls may represent neurodevelopmental markers of reduced psychiatric risk following abuse.

Alterations in the default mode-salience network circuit provide a potential mechanism supporting negativity bias in depression

Aberrant effective connectivity between default mode (DMN) and salience (SAL) networks may support the tendency of depressed individuals to find it difficult to disengage from self-focused, negatively-biased thinking and may contribute to the onset and maintenance of depression. Assessment of effective connectivity, which can statistically characterize the direction of influence between regions within neural circuits, may provide new insights into the nature of DMN-SAL connectivity disruptions in depression. Functional magnetic resonance imaging (fMRI) was collected from 38 individuals with a history of major depression and 50 healthy comparison participants during completion of an emotion-word Stroop task. Activation within DMN and SAL networks and effective connectivity between DMN and SAL, assessed via Granger causality, were examined. Individuals with a history of depression exhibited greater overall network activation, greater directed connectivity from DMN to SAL, and less directed connectivity from SAL to DMN than healthy comparison participants during negative-word trials. Among individuals with a history of depression, greater DMN-to-SAL connectivity was associated with lower overall network activation and worse task performance during positive-word trials; this pattern was not observed among healthy participants. Present findings indicate that greater network activation and, specifically, influence of DMN on SAL, support negativity bias among previously depressed individuals.

Depression, Anxiety, and Stress Among Healthcare Workers During the COVID-19 Outbreak and Relationships With Expressive Flexibility and Context Sensitivity

This study aimed at investigating depression, anxiety, and stress symptoms among healthcare workers and examine the role of expressive flexibility and context sensitivity as key components of resilience in understanding reported symptoms. We hypothesized a significant and different contribution of resilience components in explaining depression, anxiety, and stress. A total sample of 218 Italian healthcare workers participated in this study through an online survey during the lockdown, consequently to the COVID-19. The Depression Anxiety Stress Scales-21 (DASS-21) was used to measure depression, anxiety, and stress; the Flexible Regulation of Emotional Expression (FREE) scale was used to measure the ability to enhance and suppress emotional expression; the Context Sensitivity Index (CSI) was used to measure the ability to accurately perceive contextual cues and determine cue absence. Demographic and work-related data were also collected. DASS-21 cut-off scores were used to verify the mental status among the respondents. Correlational analyses examined relationships between DASS-21, FREE, and CSI, followed by three regression analyses with depression, anxiety, and stress as dependent variables, controlling for age, gender, and work experience. Enhancement and suppression abilities, cue presence, and cue absence served as independent variables. The results showed a prevalence of moderate to extremely severe symptoms of 8% for depression, 9.8% for anxiety, and 8.9% for stress. Results of correlational analysis highlighted that enhance ability was inversely associated with depression and stress. Suppression ability was inversely associated with depression, anxiety, and stress. The ability to perceive contextual cues was inversely associated with depression and anxiety. The regression analysis showed that the ability to enhance emotional expression was statistically significant to explain depression among healthcare workers. In predicting anxiety, age, and the ability to accurately perceive contextual cues and determine cue absence made substantial contributions as predictors. In the last regression model, age, work experience, and the ability to suppress emotional expression were significant predictors of stress. This study’s findings can help understand the specific contributions of enhancement and suppression abilities and sensitivity to stressor context cues in predicting depression, anxiety, and stress among healthcare workers. Psychological interventions to prevent burnout should consider these relationships.

Factor Structure, Measurement Invariance, and Concurrent Validity of the Penn State Worry Questionnaire Across Development, Psychopathology, and Culture

The Penn State Worry Questionnaire (PSWQ) is a widely used assessment of excessive worry. American undergraduate samples have predominately been used to evaluate its factor structure, which may not generalize to other developmental, cultural, and psychopathology populations. The present study tested the PSWQ's factor structure across three diverse samples: American undergraduate students (n = 3,243), Dutch high school students (n = 3,906), and American adults with psychopathology (n = 384). Exploratory, confirmatory, and multigroup confirmatory factor analyses were conducted. Measurement invariance and concurrent validity were also tested. Method-factor and two-factor models were largely equivalent and superior to a one-factor model. Invariance tests supported configural and metric invariance but only partial scalar invariance. Positively worded items but not negatively worded items demonstrated concurrent validity with anxiety and depression symptom measures and diagnoses. Overall, the PSWQ appears to measure a unitary construct. Present results warrant further testing of the PSWQ across diverse samples.

The Structure of Executive Dysfunction in Depression and Anxiety

BACKGROUND

Although research has demonstrated that depression and anxiety are associated with problematic executive function (EF), results are often inconsistent and underspecified. Delineating specific EF impairments in depression and anxiety has the potential to provide a mechanistic account of symptom presentation and course in these highly co-occurring disorders. The present study evaluated associations between components of EF and symptom dimensions of depression (depressed mood) and anxiety (anxious apprehension, anxious arousal) using factor analyses and structural equation modeling.

METHODS

Undergraduates (N = 1,123) completed self-report measures of EF in everyday life and of psychopathology. Based on a three-factor model (Miyake et al., 2000), item-level exploratory (n = 561) and confirmatory (n = 562) factor analyses were conducted on inhibition, shifting, and working memory scales chosen from the EF measure. Structural equation modeling tested the relationship of EF factors to dimensions of psychopathology using the total sample.

RESULTS

A three-factor model of EF best fit the data and was replicated via confirmatory factor analysis. Depressed mood and anxious arousal evidenced broad deficits across all EF domains, whereas anxious apprehension evidenced shifting disruptions.

LIMITATIONS

Perceived EF may not index the same constructs as performance-based EF tests. Further, the present study was restricted to college students, warranting replication in other samples.

CONCLUSIONS

Findings suggest that depressed mood and anxious arousal are characterized by a general disruption in the ability to maintain task goals, whereas anxious apprehension is characterized by cognitive inflexibility. EF impairments are likely contributory factors in the maintenance of affective disorders.

Response interference by central foils is modulated by dimensions of depression and anxiety

We used a maximum-likelihood-based model selection approach to investigate what aspects of affective traits influence flanker interference in a nonaffective task. A total of 153 undergraduates completed measures of anhedonic depression, anxious arousal, anxious apprehension, and a modified flanker task with two levels of perceptual load. For central foils, the most parsimonious model included load, depression, and anxious arousal. Participants scoring low on the depression and anxious arousal scales exhibited a typical perceptual load effect, with larger interference effects observed under low perceptual load compared with high perceptual load conditions. Increased depression symptoms were associated with a reduced perceptual load effect. However, the load effect reemerged in individuals who scored high on both depression and anxious arousal scales, but to a lesser extent than those scoring low on both. This pattern of results underscores the importance of studying co-occurring affective traits and their interactions in the same sample. For peripherally presented foils, the model that only included load as a factor was more parsimonious than any of the models incorporating affective traits. These findings suggest avenues for future research and highlight the role of diverse affective symptoms on various aspects of nonemotional attentional processing.

Effect of comorbid anxiety and depression in complicated grief on perceived cognitive failures

BACKGROUND

Bereavement is associated with cognitive difficulties, but it is unclear whether these difficulties are associated with normative and/or complicated grief (CG) and how comorbid depression and anxiety contribute to them. Self-reported "minor errors in thinking" (i.e., cognitive failures) may manifest following bereavement and be differentially affected by CG, anxiety, and depression.

METHODS

Associations between perceived cognitive failures and CG, anxiety, and depression were investigated in 581 bereaved participants. To examine both single and comorbid conditions across the spectrum of bereaved participants, these relationships were examined using both linear regressions and group comparisons.

RESULTS

Continuous measures of depression, anxiety, and grief each independently predicted perceived cognitive failures. Group comparisons indicated that the group with three comorbid conditions had the highest frequency of perceived cognitive failures and the group with no conditions had the lowest. In addition, groups with threshold depression levels (both alone and comorbid with another condition) had higher frequencies of perceived cognitive failures than other groups, suggesting that depression was more strongly associated with perceived cognitive failures than CG or anxiety.

CONCLUSIONS

Future research about cognition following bereavement should address how multiple mental health symptoms or conditions combine to affect perceived and actual cognitive capacity.

Latent ERP components of cognitive dysfunctions in ADHD and schizophrenia

OBJECTIVE

The main goal was to assess common and specific deficits of cognitive control in (Attention Deficit Hyperactivity Disorder) ADHD and schizophrenia (SZ) using event-related potentials (ERPs).

METHOD

Behavioral and EEG data in cued GO/NOGO task were recorded in 132 healthy controls (HC) and age, gender and education matched 63 ADHD adults, and 68 SZ patients.

RESULTS

N2d wave in NOGO-GO contrast of ERPs did not differ between the groups while the P3d wave discriminated SZ group from two other groups. Latent components of ERPs were extracted by blind source separation method based on second-order statistics Kropotov et al. (2017) and compared between the groups. A counterpart of N2d wave of a frontally distributed latent component was smaller in SZ indicating a specific frontal dysfunction of conflict detection in SZ. Two centrally distributed P3 sub-components were reduced in both groups indicating a non-specific dysfunction of action inhibition operations in ADHD and SZ.

CONCLUSION

A pattern of specific and common dysfunctions in terms of latent ERP components shows a more complex picture of functional impairment in schizophrenia and ADHD in comparison to conventional N2/P3 ERP description.

SIGNIFICANCE

The latent component approach shows a functionally different pattern of cognitive control impairment in comparison to the conventional ERP analysis.

Interactions Between Oxytocin Receptor Gene Methylation and Callous-Unemotional Traits Impact Socioaffective Brain Systems in Conduct-Disordered Offenders

BACKGROUND

The developmental trajectory of psychopathy seemingly begins early in life and includes the presence of callous-unemotional (CU) traits (e.g., perturbed socioaffective reactivity and empathy, callousness) in youths with conduct disorder (CD). Whereas oxytocin receptor gene methylation (OXTR_Meth) and its downstream neuromodulatory effects are deemed relevant to CU traits, nothing is known of how OXTR_Meth interacts with CU traits to impact socioaffective brain systems in youngsters with CD.

METHODS

Hence, we uniquely probed OXTR_Meth × CU trait interactions on corticolimbic activity and amygdala subregional connections during recognition and resonance of distressing socioaffective stimuli (angry and fearful faces), in juvenile offenders with CD (n = 39) versus matched healthy control youths (n = 27).

RESULTS

Relative to healthy control youths, elevated OXTR_Meth and CU levels in youths with CD essentially interacted to predict frontoparietal hyperactivity and amygdalo-frontoparietal disconnection during task performance. Specifically, increasing OXTR_Meth and CU levels in youths with CD interactively predicted midcingulate hyperactivity during both emotion conditions, with insular, temporoparietal, and precuneal hyperactivity additionally emerging during emotion recognition. Interactions between high OXTR_Meth and CU levels in youths with CD additionally predicted centromedial amygdala decoupling from ventromedial/orbitofrontal regions during emotion recognition, along with basolateral amygdala decoupling from precuneal and temporoparietal cortices during emotion resonance.

CONCLUSIONS

These results uniquely suggest that interactions between OXTR_Meth and CU traits in youths with CD may affect brain systems critical to decoding and integrating socioaffective information. Developmental models of CU traits and psychopathy could thus possibly advance by further examining OXTR epigenetic effects, which may hold promise for indicated prevention and personalized treatment by targeting oxytocinergic function.

Effect of Threat on Right dlPFC Activity during Behavioral Pattern Separation

It has long been established that individuals with anxiety disorders tend to overgeneralize attributes of fearful stimuli to nonfearful stimuli, but there is little mechanistic understanding of the neural system that supports overgeneralization. To address this gap in our knowledge, this study examined effect of experimentally induced anxiety in humans on generalization using the behavioral pattern separation (BPS) paradigm. Healthy subjects of both sexes encoded and retrieved novel objects during periods of safety and threat of unpredictable shocks while we recorded brain activity with fMRI. During retrieval, subjects were instructed to differentiate among new, old, and altered images. We hypothesized that the hippocampus and dorsolateral prefrontal cortex (dlPFC) would play a key role in the effect of anxiety on BPS. The dlPFC, but not the hippocampus, showed increased activity for altered images compared with old images when retrieval occurred during periods of threat compared with safety. In addition, accuracy for altered items retrieved during threat was correlated with dlPFC activity. Together, these results suggest that overgeneralization in anxiety patients may be mediated by an inability to recruit the dlPFC, which mediates the cognitive control needed to overcome anxiety and differentiate between old and altered items during periods of threat.SIGNIFICANCE STATEMENT Anxiety and posttraumatic stress disorder patients generalize fear to nonfearful fear stimuli, making it difficult to regulate anxiety. Understanding how anxiety affects generalization is key to understanding the overgeneralization experienced by these patients. We examined this relationship in healthy subjects by studying how threat of shock affects neural responses to previously encountered stimuli. Although previous studies point to hippocampal involvement, we found that threat affected activity in the dorsolateral prefrontal cortex (dlPFC), rather than the hippocampus, when subjects encountered slightly altered versions of the previously encountered items. Importantly, this dlPFC activity predicted performance for these items. Together, these results suggest that the dlPFC is important for discrimination during elevated anxiety and that overgeneralization may reflect a deficit in dlPFC-mediated cognitive control.

Functional indexes of reactive cognitive control: ERPs in cued go/no-go tasks

We aimed to determine the functional meaning of latent (hidden) components decomposed from ERPs, in the context of a go/no-go paradigm. To accomplish this, we used a new group blind source separation method, based on joint diagonalization of covariance matrices of ERPs. Four variants of a frequently used go/no-go paradigm were designed, in which operations of reactive cognitive control, such as conflict detection and action inhibition, were independently manipulated. The results showed that a latent component, generated in the anterior cingulate cortex, induced N2/P3 fluctuation only in conditions in which the prepotent model was violated, and thus can be associated with conflict detection operations. In contrast, the two latent components generated in the vicinity of the central sulcus induced P3-like fluctuations in conditions in which the prepared action was suppressed, and thus can be associated with action inhibition operations. The advantages and limitations of the new blind source separation method in relation to ERP research are also discussed.

Investigating the nature of co-occurring depression and anxiety: Comparing diagnostic and dimensional research approaches

BACKGROUND

Although approximately half of adults diagnosed with a depressive or anxiety disorder exhibit their simultaneous co-occurrence, traditional research has centered on single-target diagnoses, overlooking comorbidities within samples. In this article, we review and extend the literature that directly investigates co-occurring depression and anxiety, with the goal of shifting the focus from co-occurring diagnoses to symptom dimensions.

METHODS

First, we review studies that have directly compared psychobiological features (neural, neuroendocrine, autonomic) across depression, anxiety, and their co-occurrence, defined either categorically or dimensionally. Second, we analyze adults' diurnal cortisol secretion to examine the independent and interactive relations of continuously-assessed depressive and anxiety symptoms to neuroendocrine function.

RESULTS

Previous findings on the psychobiology of diagnostic co-occurrence are mixed. While nascent, evidence from dimensionally focused studies suggests that co-occurring levels of depressive and anxiety symptoms can interact with one another, as reflected in a distinct psychobiological profile for individuals with high levels of both symptom dimensions. Results of our analyses support this formulation: we found that depressive and anxiety symptom dimensions interacted consistently in their relation to the measures of diurnal cortisol.

LIMITATIONS

The illustrative sample was relatively small and included only women; future research should examine generalizability of these findings.

CONCLUSIONS

A dimensional approach to investigating the psychobiology of co-occurring depression and anxiety affords both conceptual and practical advantages. Simultaneously assessing depressive and anxiety symptom dimensions can efficiently capture their unique, shared, and interactive features, thereby identifying targets for intervention across a wide range of symptom presentations.

Testing differential susceptibility: Plasticity genes, the social environment, and their interplay in adolescent response inhibition

OBJECTIVES

Impaired inhibitory control is a key feature of attention-deficit/hyperactivity disorder (ADHD). We investigated gene-environment interaction (GxE) as a possible contributing factor to response inhibition variation in context of the differential susceptibility theory. This states individuals carrying plasticity gene variants will be more disadvantaged in negative, but more advantaged in positive environments.

METHODS

Behavioural and neural measures of response inhibition were assessed during a Stop-signal task in participants with (N = 197) and without (N = 295) ADHD, from N = 278 families (age M = 17.18, SD =3.65). We examined GxE between candidate plasticity genes (DAT1, 5-HTT, DRD4) and social environments (maternal expressed emotion, peer affiliation).

RESULTS

A DRD4 × Positive peer affiliation interaction was found on the right fusiform gyrus (rFG) activation during successful inhibition. Further, 5-HTT short allele carriers showed increased rFG activation during failed inhibitions. Maternal warmth and positive peer affiliation were positively associated with right inferior frontal cortex activation during successful inhibition. Deviant peer affiliation was positively related to the error rate.

CONCLUSIONS

While a pattern of differential genetic susceptibility was found, more clarity on the role of the FG during response inhibition is warranted before firm conclusions can be made. Positive and negative social environments were related to inhibitory control. This extends previous research emphasizing adverse environments.

Prevalence and pattern of executive dysfunction in school age children with congenital heart disease

OBJECTIVE

Executive function, a set of cognitive skills important to social and academic outcomes, is a specific area of cognitive weakness in children with congenital heart disease (CHD). We evaluated the prevalence and profile of executive dysfunction in a heterogeneous sample of school aged children with CHD, examined whether children with executive dysfunction are receiving school services and support, and identified risk factors for executive dysfunction at school age.

DESIGN

Ninety-one school aged patients completed questionnaires, including the Behavior Rating Inventory of Executive Function (BRIEF) and a medical history questionnaire. An age- and gender- matched control sample was drawn from a normative database.

RESULTS

Children with CHD had a higher rate of parent reported executive dysfunction (OR = 4.37, P < .0001), especially for working memory (OR = 8.22, P < .0001) and flexibility (OR = 8.05, P < .0001). Those with executive dysfunction were not more likely to be receiving school services (P > .05). Gender, premature birth (≤37 weeks), and CHD with aortic obstruction were predictive of executive dysfunction, especially for behavior regulation skills.

CONCLUSIONS

School aged children with CHD have an increased prevalence of executive dysfunction, especially problems with working memory and flexibility, and are underserved by the school system. The increased risk for executive dysfunction in those with CHD and prematurity or CHD with aortic obstruction suggests an etiology of delayed brain development in the fetal and neonatal periods, while male gender may increase susceptibility to brain injury. This study highlights the need for regular neurodevelopmental follow up in children with CHD, and a need to better understand mechanisms that contribute to adverse neurodevelopmental outcomes.

Executive function deficits associated with current and past major depressive symptoms

BACKGROUND

Although there has been extensive research showing that depression is associated with executive function (EF) deficits, the nature of these deficits is not clearly delineated. Specifically, previous reviews on this topic have yielded different conclusions about the particular domains of EF that are disrupted in depressed individuals. Further, research on whether these deficits persist after depressed mood has remitted is less prevalent and not consistent.

METHODS

In two independent samples of college students, we examined associations between clinical ratings of current and past symptoms of a Major Depressive Episode (MDE) and difficulties in two domains of EF: inhibition and shifting. In Study 1 (n=162), EF was measured using behavioral tasks shown to index these two domains. In Study 2 (n=95), EF was measured using a self-report questionnaire believed to capture EF difficulties experienced in daily life.

RESULTS

In both studies, past MDE symptoms were associated with worse shifting. In contrast, current MDE symptoms were associated with worse inhibition, though only on the behavioral measure (in Study 1).

LIMITATIONS

Both studies used college samples and retrospective assessments of past symptoms. Further, only two domains of EF were examined, and the EF measures employed in each study have their own unique methodological limitations.

CONCLUSIONS

Findings suggest that inhibition deficits vary as a function of current symptoms and thus may be a by-product of distress rather than a causal contributor. In contrast, shifting deficits associated with depression appear to be more enduring, suggesting that they could contribute to risk for depression.

Specifically altered brain responses to threat in generalized anxiety disorder relative to social anxiety disorder and panic disorder

Background

Despite considerable effort, the neurobiological underpinnings of hyper-responsive threat processing specific to patients suffering from generalized anxiety disorder (GAD) remain poorly understood. The current functional magnetic resonance imaging (fMRI) study aims to delineate GAD-specific brain activity during immediate threat processing by comparing GAD patients to healthy controls (HC), to social anxiety disorder (SAD) and to panic disorder (PD) patients.

Method

Brain activation and functional connectivity patterns to threat vs. neutral pictures were investigated using event-related fMRI. The sample consisted of 21 GAD, 21 PD, 21 SAD and 21 HC.

Results

GAD-specific elevated activity to threat vs. neutral pictures was found in cingulate cortex, dorsal anterior insula/frontal operculum (daI/FO) and posterior dorsolateral prefrontal cortex (dlPFC). Defining these effects as seed regions, we detected GAD-specific increased functional connectivity to threat vs. neutral pictures between posterior dlPFC and ventrolateral prefrontal cortex, between cingulate cortex and amygdala, between cingulate cortex and anterior insula, as well as decreased functional connectivity between daI/FO and mid-dlPFC.

Conclusion

The findings present the first evidence for GAD-specific neural correlates of hyper-responsive threat processing, possibly reflecting exaggerated threat sensitivity, maladaptive appraisal and attention-allocation processes.

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Threat processing investigation across multiple anxiety disorders

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First neural evidence of GAD-specific threat-related alterations

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GAD-specific alterations primarily located in prefrontal cortex

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Alterations are suggestive of exaggerated threat sensitivity

Resting-state functional connectivity differentiates anxious apprehension and anxious arousal

Brain regions in the default mode network (DMN) display greater functional connectivity at rest or during self-referential processing than during goal-directed tasks. The present study assessed resting-state connectivity as a function of anxious apprehension and anxious arousal, independent of depressive symptoms, in order to understand how these dimensions disrupt cognition. Whole-brain, seed-based analyses indicated differences between anxious apprehension and anxious arousal in DMN functional connectivity. Lower connectivity associated with higher anxious apprehension suggests decreased adaptive, inner-focused thought processes, whereas higher connectivity at higher levels of anxious arousal may reflect elevated monitoring of physiological responses to threat. These findings further the conceptualization of anxious apprehension and anxious arousal as distinct psychological dimensions with distinct neural instantiations.

State anxiety impairs attentional control when other sources of control are minimal

Research suggests anxiety impairs attentional control; however, this effect has been unreliable. We argue that anxiety's impairment of attentional control is subtle, and can be obscured by other non-emotional sources of control. We demonstrate this by examining conflict adaptation, an enhancement in attentional control following a trial with high conflict between distracter and target stimuli. Participants completed a Stroop task featuring incongruent (e.g. RED in green font; high-conflict) and control (e.g. +++ in green font; low-conflict) trials. More state-anxious participants showed greater Stroop interference following control trials, but interference was uniformly low following incongruent trials. This suggests state anxiety can impair attention, but other sources of top-down control - such as conflict adaptation - can easily overcome this impairment. This is consistent with recent theories of anxious cognition and shows that anxiety researchers must attend to the dynamics and sources of attentional control.

Executive functioning profiles from the BRIEF across pediatric medical disorders: Age and diagnosis factors

The objective of the study was to compare executive functioning (EF) profiles across several pediatric medical conditions and explore the influence of age of diagnosis and evaluation. A retrospective, cross-sectional study of 734 children aged 5 to 18 years was conducted across five medical groups (brain tumor, leukemia [ALL], epilepsy [EPI], neurofibromatosis type 1 [NF1], and ornithine transcarbamylase deficiency [OTC-D]), attention deficit hyperactivity disorder (ADHD) controls, and matched healthy controls. We compared groups across the scales of a parent-completed Behavior Rating Inventory of Executive Functioning (BRIEF) using a repeated measures analysis of variance (ANOVA). Separate ANOVAs were conducted to look at age factors. The results showed that the ADHD group differed from all other groups and had the highest level of reported EF problems. The NF1 and OTC-D groups differed significantly from the healthy comparison group for overall EF problems, while the EPI and cancer groups did not. Working memory was the most elevated scale across medical groups, followed by plan/organize. Children with medical disorders were two to four times more likely than healthy controls to have clinically significant problems in several EF domains. There was a main effect for age at diagnosis and age at evaluation. A subset of children with medical disorders were found to have parent-reported EF difficulties, with particular vulnerability noted in working memory and organizational/planning skills. This has relevance for the development of interventions that may be helpful across disorders. Children with particular diagnoses and earlier age of diagnosis and evaluation had greater reported EF problems.

Independent component analysis of functional networks for response inhibition: Inter-subject variation in stop signal reaction time

Cognitive control is a critical executive function. Many studies have combined general linear modeling and the stop signal task (SST) to delineate the component processes of cognitive control. For instance, by contrasting stop success (SS) and stop error (SE) trials in the SST, investigators examined regional responses to stop signal inhibition. In contrast to this parameterized approach, independent component analysis (ICA) elucidates brain networks subserving cognitive control. In our earlier work of 59 adults performing the SST during fMRI, we characterized six independent components (ICs). However, none of these ICs correlated with stop signal performance, raising questions about their behavioral validity. Here, in a larger sample (n = 100), we identified and explored 23 ICs for correlation with the stop signal reaction time (SSRT), a measure of the efficiency of response inhibition. At a corrected threshold (P < 0.0005), a paracentral lobule-midcingulate network and a left inferior parietal-supplementary motor-somatomotor network showed a positive correlation between SE beta weight and SSRT. In contrast, a midline cerebellum-thalamus-pallidum network showed a negative correlation between SE beta weight and SSRT. These findings suggest that motor preparation and execution prolongs the SSRT, likely via an interaction between the go and stop processes as suggested by the race model. Behaviorally, consistent with this hypothesis, the difference in G and SE reaction times is positively correlated with SSRT across subjects. These new results highlight the importance of cognitive motor regions in response inhibition and support the utility of ICA in uncovering functional networks for cognitive control in the SST.

The neurobiology of emotion-cognition interactions: fundamental questions and strategies for future research

Recent years have witnessed the emergence of powerful new tools for assaying the brain and a remarkable acceleration of research focused on the interplay of emotion and cognition. This work has begun to yield new insights into fundamental questions about the nature of the mind and important clues about the origins of mental illness. In particular, this research demonstrates that stress, anxiety, and other kinds of emotion can profoundly influence key elements of cognition, including selective attention, working memory, and cognitive control. Often, this influence persists beyond the duration of transient emotional challenges, partially reflecting the slower molecular dynamics of catecholamine and hormonal neurochemistry. In turn, circuits involved in attention, executive control, and working memory contribute to the regulation of emotion. The distinction between the 'emotional' and the 'cognitive' brain is fuzzy and context-dependent. Indeed, there is compelling evidence that brain territories and psychological processes commonly associated with cognition, such as the dorsolateral prefrontal cortex and working memory, play a central role in emotion. Furthermore, putatively emotional and cognitive regions influence one another via a complex web of connections in ways that jointly contribute to adaptive and maladaptive behavior. This work demonstrates that emotion and cognition are deeply interwoven in the fabric of the brain, suggesting that widely held beliefs about the key constituents of 'the emotional brain' and 'the cognitive brain' are fundamentally flawed. We conclude by outlining several strategies for enhancing future research. Developing a deeper understanding of the emotional-cognitive brain is important, not just for understanding the mind but also for elucidating the root causes of its disorders.

Executive Function Deficits in Daily Life Prospectively Predict Increases in Depressive Symptoms

Executive function (EF) deficits are associated with depression. Given that few prospective studies have been conducted, it is unclear whether deficits contribute to depression or result from it. The present study examined whether self-reported EF prospectively predicted worsening of depression symptoms. Time 1 (T1) shifting, inhibition, and working memory (WM) were assessed in relation to T1 and time 2 (T2) depressive symptoms in participants pre-selected to range in risk for depression. Analyses indicated that poorer EF at T1 predicted increases in depressive symptoms and furthermore that this relationship was specific to WM. In contrast, a bidirectional relationship was not evident, as depressive symptoms did not prospectively predict changes in EF. Finally, T1 EF accounted for T2 depressive symptoms beyond two well established predictors of depression: depressive symptoms at T1 and rumination at T2. These findings suggest that EF deficits play an active role in depression onset, maintenance, and/or recurrence.

Transdiagnostic dimensions of anxiety and depression moderate motivation-related brain networks during goal maintenance

BACKGROUND

Advancing research on the etiology, prevention, and treatment of psychopathology requires the field to move beyond modular conceptualizations of neural dysfunction toward understanding disturbance in key brain networks. Although some studies of anxiety and depression have begun doing so, they typically suffer from several drawbacks, including: (1) a categorical approach ignoring transdiagnostic processes, (2) failure to account for substantial anxiety and depression comorbidity, (3) examination of networks at rest, which overlooks disruption manifesting only when networks are challenged. Accordingly, the present study examined relationships between transdiagnostic dimensions of anxiety/depression and patterns of functional connectivity while goal maintenance was challenged.

METHODS

Participants (n = 179, unselected community members and undergraduates selected to be high/low on anxiety/depression) performed a task in which goal maintenance was challenged (color-word Stroop) while fMRI data were collected. Analyses examined moderation by anxiety/depression of condition-dependent coupling between regions of dorsolateral prefrontal cortex (dlPFC) previously associated with approach and avoidance motivation and amygdala/orbitofrontal cortex (OFC).

RESULTS

Anxious arousal was positively associated with amygdala↔right dlPFC coupling. Depression was positively associated with OFC↔right dlPFC coupling and negatively associated with OFC↔left dlPFC coupling.

CONCLUSIONS

Findings advance the field toward an integrative model of the neural instantiation of anxiety/depression by identifying specific, distinct dysfunctions associated with anxiety and depression in networks important for maintaining approach and avoidance goals. Specifically, findings shed light on potential neural mechanisms involved in attentional biases in anxiety and valuation biases in depression and underscore the importance of examining transdiagnostic dimensions of anxiety/depression while networks are challenged.

Executive function mediates effects of gestational age on functional outcomes and behavior in preschoolers

OBJECTIVE

To investigate the role of executive function (EF) skills, measured by parent-rating and performance-based instruments, as mediators of the effects of gestational age (GA) on functional outcomes and behavior symptoms in preterm (PT) and full-term (FT) preschoolers.

PATIENTS AND METHODS

Children born PT (n = 70; mean GA, 29.6 weeks; mean birth weight, 1365 g) were compared to children born FT (n = 79) on composite measures of EF (using the Behavior Rating Inventory of Executive Function and a performance-based EF battery), adaptive function, prereading skills, and behavior symptoms. For the entire sample, mediation analyses examined the effect of GA on the outcomes with EF as mediator.

RESULTS

Compared to children born FT, children born PT had significantly higher parent-rated EF scores and lower performance-based EF scores, both indicating more problems; furthermore, children born PT had lower adaptive function and prereading scores and more problematic behavior. GA contributed to adaptive function, prereading skills, and behavior symptoms for all children. EF acted as a mediator of GA for all 3 outcomes; different patterns emerged for parent-rated and performance-based EF evaluations. For adaptive function, both EF measures significantly mediated the effects of GA; for prereading skills, only performance-based EF was significant; for behavior symptoms, only parent-rated EF was significant.

CONCLUSIONS

We propose standard assessment of EF, using both parent-rating and performance-based EF measures, in young PT children and other children at the risk of EF impairments. EF skills are measurable, mediate important functional outcomes, and may serve as intervention targets.

Complementary assessments of executive function in preterm and full-term preschoolers

Executive functions (EFs) are interrelated cognitive processes that have been studied in relation to behavior, attention, academic achievement, and developmental disorders. Studies of EF skills assessed through parent report and performance-based measures show correlations between them ranging from none to modest. Few studies have examined the relationship between EF skills measured through parent report and performance-based measures in relation to adaptive function. The present study included preschool children born preterm as a population at high risk for EF impairments. Preschool children (N = 149) completed a battery of EF tasks that assess working memory, response inhibition, idea generation, and attention shifting or cognitive flexibility. Parents reported on children's EF and adaptive skills. Preterm children showed more parent-rated and performance-based EF impairments than did full-term children. The combined use of either parent report or performance-based measures resulted in the identification of a large number of children at risk for EF impairment, especially in the preterm group. Both parent report and performance-based EF measures were associated with children's adaptive function. EF skills are measurable in young child'ren, and we suggest that EF skills may serve as targets for intervention to improve functional outcomes. We recommend the use of both parent report and performance-based measures to characterize children's EF profiles and to customize treatment.

Dissociable self effects for emotion regulation: a study of Chinese major depressive outpatients

Reappraisal is an adaptive emotion regulation strategy while the role of self-perspective in reappraisal process of depressed patients is largely unknown in terms of goals (valence/arousal) and tactics (detachment/immersion). In this study, 12 depressed individuals and 15 controls were scanned with MRI during which they either attend naturally to emotional stimuli, or adopt detachment/immersion strategy. Behaviorally, no group differences in self-reported emotion regulation effectiveness were found. In addition, we observed that (1) patients were less able to downregulate amygdala activation with recruitment of more dorsal lateral prefrontal cortex (dlPFC) when adopting detachment strategy regardless of valence, and this preserved ability to regulate emotion was inversely associated with severity of symptoms; (2) patients had deficits in upregulating amygdala activation when adopting immersion strategy, with less inferior frontal gyrus (IFG) activation and strengthening coupling of dlPFC and ventral medial prefrontal cortex (vmPFC) with amygdala; (3) comparison between groups yielded that patients showed stronger vmPFC activation under either self-detached or self-immersed condition. In conclusion, impaired modulatory effects of amygdala in depressed patients are compensated with strengthening cognitive control resources, with dissociable effects for different self-perspectives in reappraisal. These results may help clarify the role of self-perspective underlying reappraisal in major depression.

Functional and structural comparison of visual lateralization in birds - similar but still different

Vertebrate brains display physiological and anatomical left-right differences, which are related to hemispheric dominances for specific functions. Functional lateralizations likely rely on structural left-right differences in intra- and interhemispheric connectivity patterns that develop in tight gene-environment interactions. The visual systems of chickens and pigeons show that asymmetrical light stimulation during ontogeny induces a dominance of the left hemisphere for visuomotor control that is paralleled by projection asymmetries within the ascending visual pathways. But structural asymmetries vary essentially between both species concerning the affected pathway (thalamo- vs. tectofugal system), constancy of effects (transient vs. permanent), and the hemisphere receiving stronger bilateral input (right vs. left). These discrepancies suggest that at least two aspects of visual processes are influenced by asymmetric light stimulation: (1) visuomotor dominance develops within the ontogenetically stronger stimulated hemisphere but not necessarily in the one receiving stronger bottom-up input. As a secondary consequence of asymmetrical light experience, lateralized top-down mechanisms play a critical role in the emergence of hemispheric dominance. (2) Ontogenetic light experiences may affect the dominant use of left- and right-hemispheric strategies. Evidences from social and spatial cognition tasks indicate that chickens rely more on a right-hemispheric global strategy whereas pigeons display a dominance of the left hemisphere. Thus, behavioral asymmetries are linked to a stronger bilateral input to the right hemisphere in chickens but to the left one in pigeons. The degree of bilateral visual input may determine the dominant visual processing strategy when redundant encoding is possible. This analysis supports that environmental stimulation affects the balance between hemispheric-specific processing by lateralized interactions of bottom-up and top-down systems.