Executive function in pediatric bipolar disorder and attention-deficit hyperactivity disorder: in search of distinct phenotypic profiles

Neural correlates of executive function and attention in children with ADHD: An ALE meta-analysis of task-based functional connectivity studies

We conducted a comprehensive meta-analysis of task-based functional MRI studies on executive function and attention in children with attention deficit hyperactivity disorder (ADHD). We searched for studies published before March 20, 2023, in PubMed, Cochrane Library, Web of Science, EBSCO, Embase, and Scopus. The ALE (activation likelihood estimation) method was used to detect differences in brain activation between children with ADHD and comparison children. Fifty-seven (57) studies were included, with 2,231 participants (1,062 children with ADHD). Based on the omnibus meta-analysis findings, significant hypoactivation in children with ADHD relative to comparisons was observed in the frontoparietal network, putamen, insula, cingulate gyrus, and middle temporal gyrus, while ADHD-related hyperactivation was present in the occipital lobe, declive, middle frontal gyrus, and parahippocampal gyrus. This study highlights the critical involvement of the parietal lobe. Results also revealed abnormalities in the frontal lobe and brainstem, suggesting unintegrated primitive reflexes. For stimulant-naive children with ADHD, significant hypoactivation in the right cerebrum was observed compared to controls. Finally, dysfunctional connectivity between the frontoparietal network and the striatum may lead to inefficient working memory, while the cerebellum plays a crucial role in inhibitory control and attention tasks. These findings provide important insights into the pathology of ADHD.

Neurocognitive correlates of polygenic risk for bipolar disorder among youth with and without bipolar disorder

INTRODUCTION

There is well-established evidence of reduced neurocognitive performance in adults and youth with bipolar disorder (BD). However, little is known about the polygenic underpinnings of neurocognition in individuals with BD, particularly in youth. The current study aimed to examine the association between polygenic risk score for BD (BD-PRS) and neurocognition among youth with BD and healthy controls (HC).

METHODS

129 youth of European ancestry (72 BD, 57 HC), ages 13-20 years, were included. Six neurocognitive tasks within the Cambridge Neuropsychological Test Automated Battery were assessed. General linear models were used to examine the association between BD-PRS and neurocognitive composite scores, controlling for age, sex, IQ, and two genetic principal components.

RESULTS

In the overall sample, higher BD-PRS was associated with significantly poorer affective processing (β = -0.25, p = 0.01), decision-making (β = -0.23, p = 0.02), and sustained attention (β = -0.28, p = 0.002). Secondary analyses revealed that higher BD-PRS was associated with significantly poorer sustained attention within the BD group (β = -0.27, p = 0.04), and with significantly poorer affective processing within the HC group (β = -0.29, p = 0.04).

LIMITATIONS

Cross-sectional design. Modest sample size may have reduced power to detect smaller effect sizes.

CONCLUSION

The current study found that higher BD-PRS generated based on adult GWAS was associated with poorer neurocognitive performance in youth with BD and HC. Future longitudinal studies incorporating repeated neurocognitive assessments would further inform whether the associations of BD-PRS with neurocognition vary from youth to adulthood, and whether BD-PRS is associated with differential neurodevelopmental trajectories in individuals with and without BD.

Gestational organophosphate esters (OPEs) and executive function in adolescence: The HOME Study

BACKGROUND

Evidence from toxicological studies indicate organophosphate esters (OPEs) are neurotoxic, but few epidemiological studies investigated associations between gestational OPEs and executive function.

OBJECTIVE

To examine the associations between gestational concentrations of OPE urinary metabolites and executive function at 12 years.

METHODS

We used data from 223 mother-adolescent dyads from the Health Outcomes of Measures of the Environment (HOME) Study. Women provided spot urine samples at 16 weeks gestation, 26 weeks gestation, and at delivery for quantification of bis(1,3-dichloro-2-propyl) phosphate, bis-2-chloroethyl phosphate (BCEP), diphenyl phosphate (DPHP), and di-n-butyl phosphate (DNBP). Executive function was assessed at age 12 years using the parent- and self-report Behavior Rating Inventory of Executive Function (BRIEF2). Covariate-adjusted associations between specific gravity-corrected OPEs and BRIEF2 scores were estimated using multiple informant models. Bayesian Kernel Machine Regression (BKMR) was used to assess the impact of all OPEs simultaneously.

RESULTS

Parent- and self-report BRIEF2 indices and composite scores were weakly to moderately correlated (rs = 0.32-0.41). A natural-log unit increase in BCEP at 26 weeks was associated with approximately a 1-point increase on the self-report Cognitive Regulation Index [CRI] (95% CI 0.4, 2.3), the Emotion Regulation Index [ERI] (95% CI 0.3, 2.2), and the Global Executive Composite [GEC] (95% CI 0.4, 2.2), indicating poorer performance. Higher DPHP at 16 weeks was associated with lower parent-report GEC score (β = -1.1, 95% CI -2.3, -0.003). BKMR identified BCEP and DNBP at 26 weeks as important contributors to CRI and ERI, respectively.

CONCLUSION

OPE metabolites during gestational development, particularly BCEP, may influence adolescent executive function. However, since the FDR p-values failed to reach statistical significance, additional studies would benefit from using larger cohorts.

Shared and Distinct Neurobiological Bases of Bipolar Disorder and Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Comparative Meta-Analysis of Structural Abnormalities

OBJECTIVE

Pediatric bipolar disorder (PBD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur and share dysfunctions in affective and cognitive domains. As the neural substrates underlying their overlapping and dissociable symptomatology have not been well delineated, a meta-analysis of whole-brain voxel-based morphometry studies in PBD and ADHD was conducted.

METHOD

A systematic literature search was performed in PubMed, Web of Science, and Embase. The seed-based d mapping toolbox was used to identify altered clusters of PBD or ADHD and obtain their conjunctive and comparative abnormalities. Suprathreshold patterns were subjected to large-scale network analysis to identify affected brain networks.

RESULTS

The search revealed 10 PBD studies (268 patients) and 32 ADHD studies (1,333 patients). Decreased gray matter volumes in the right insula and anterior cingulate cortex relative to typically developing individuals were conjunctive in PBD and ADHD. Reduced volumes in the right inferior frontal gyrus, left orbitofrontal cortex, and hippocampus were more substantial in PBD, while decreased volumes in the left precentral gyrus, left inferior frontal gyrus, and right superior frontal gyrus were more pronounced in ADHD. Neurodevelopmental effects modulated patterns of the left hippocampus in PBD and those of the left inferior frontal gyrus in ADHD.

CONCLUSION

These findings suggest that PBD and ADHD are characterized by both common and distinct patterns of gray matter volume alterations. Their overlapping abnormalities may represent a transdiagnostic problem of attention and emotion regulation shared by PBD and ADHD, whereas the disorder-differentiating substrates may contribute to the relative differences in cognitive and affective features that define the 2 disorders.

PLAIN LANGUAGE SUMMARY

Pediatric bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur, with overlapping changes in emotional and cognitive functioning. This meta-analysis summarizes findings from 10 articles on BD and 32 articles on ADHD to identify similarities and differences in brain structure between youth with BD and youth with ADHD. The authors found that both disorders share decreased gray matter volumes in the right insula and anterior cingulate cortex, which play important roles in emotion processing and attention, respectively. Youth with BD had decreased gray matter volume in the right inferior frontal gyrus, left orbitofrontal gyrus, and left hippocampus, while youth with ADHD had decreased volumes in the left precentral gyrus, left inferior frontal gyrus, and right superior frontal gyrus.

STUDY PREREGISTRATION INFORMATION

Structural Brain Abnormalities of Attention-Deficit/Hyperactivity Disorder and Bipolar Disorder in Children/Adolescents: An Overlapping Meta-analysis; https://osf.io; trg4m.

Effects of comorbidity on executive functions among children with ADHD, finding trends

There is still no basic overview about the effect of various types of comorbidity in executive functions due to two main reasons: (1) the type and number of comorbidities in ADHD is significantly varied, (2) EFs are very diverse and have different neuropsychological properties. Our objective was to determine the effect of comorbid disorders (number and type) on the performance in a wide range (seven) of executive functions in a sample of children with ADHD. Fifty-five male children aged seven to nine years with ADHD were divided into six groups: G1 = ADHD only (ADHD-O), G1 = Oppositional defiant disorder (ODD), G3 = (anxiety/depressive disorder (ADD), G4 = ODD + ADD, G5 = ODD + learning disorder (LD), G6 = ODD + LD + conduct disorder (CD). The six groups exhibited different number of deficits in EFs; G1 showed only 1 deficit in contrast, G6 presented 11. Statistical analysis (ANOVA and logistic regression) identified three most affected EFs: Working memory, generation/classification of semantic categories, and inhibitory control. Alterations in EFs increased mainly in relation to the increase of the specific number and type of comorbidity. To date, no studies have addressed comorbidity from this perspective. A wide range approach of EF confirms the need to further study comorbidity in ADHD from a wide range/variety perspective and determine all possible combinations (number/type) to clarify its contribution to the complex neuropsychology functioning in ADHD.

Distinct effects of different neurofeedback protocols on the neural mechanisms of response inhibition in ADHD

OBJECTIVE

In attention deficit/hyperactivity disorder (ADHD), impaired response inhibition is frequently observed. A promising non-pharmacological treatment is electroencephalography (EEG)-neurofeedback (NF) training. However, the widely used theta-down/beta-up regulation (↓θ↑β) NF protocol may not be optimal for targeting these deficits. We examined how neurofeedback protocols training the upregulation of theta and/or beta power affect inhibitory control in children and adolescents with ADHD.

METHODS

64 patients with ADHD took part in the three NF trainings. Aside from parent-reported ADHD symptoms and behavioural performance data, neurophysiological parameters collected via a Go/Nogo task and corrected to account for intraindividual variability were compared in a pre-post design and to an ADHD (n = 20) as well as a typically developing control group (n = 24).

RESULTS

The examined NF protocols resulted in similar improvements in response inhibition with the neurophysiological mechanisms differing substantially. The upregulation of theta led to a specific Nogo-P3 increase, while training beta upregulation as well as the combined protocol resulted in less specific effects.

CONCLUSIONS

This study shows distinct effects of different theta/beta-neurofeedback protocols on the neural mechanisms underlying improvements in response inhibition in patients with ADHD.

SIGNIFICANCE

These effects shed further light on the oscillatory dynamics underlying cognitive control in ADHD and how these may be targeted in neurofeedback treatments.

Cognitive, Family, and Quality-of-Life Characteristics of Youth with Depression Associated with Bipolar Disorder

Background: Depression associated with bipolar disorder (BD) is more common compared to mania. Cognitive, family, and quality-of-life (QOL) factors associated with pediatric bipolar depression are understudied. The goal of this study was to evaluate cognitive, family environmental, and QOL characteristics of youth with bipolar depression. Methods: Thirty-two youth (12-18 years of age) with BD type I currently depressed were recruited from inpatient and outpatient setting. Subjects were assessed using the Behavior Rating Inventory of Executive Function (BRIEF), the Family Environment Scale (FES), and the Child Health Questionnaire-Parental-Form 50 (CHQ-PF50). Results were compared with population norms and the relationship between these domains was calculated. Results: Youth with depression associated with BD did not show significant impairment in executive functions. They displayed impaired family environment in the domains of cohesion, independence, achievement orientation, and organization. Youth also displayed impairments in the psychosocial health domains compared with the population normative data. The CHQ-Psychosocial health significantly negatively correlated with the BRIEF-Global Executive Control score (r = -0.76, p < 0.0001). Conclusion: Depression in youth with BD is associated with impairments in family functioning and QOL. Impairments in psychosocial QOL are associated with cognitive functioning. Further intervention studies examining executive functioning and family environment as treatment targets are needed. ClinicalTrials.gov identifier:NCT00232414.

Executive functioning in body dysmorphic disorder and obsessive-compulsive disorder

OBJECTIVE

To assess executive functions (EFs) in patients with body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) compared with healthy controls.

METHODS

Adults diagnosed with BDD (n = 26) or OCD (n = 29) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and healthy controls (n = 28) underwent validated and computerized neuropsychological tests, spatial working memory (SWM), intra-extra-dimensional set shifting (IED), and stop signal task (SST), from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Test performance was compared between groups, and correlated with standardized symptom severity of BDD and OCD. Significance level was set to P < .05.

RESULTS

There were no statistically significant between-group differences on key outcome measures in SWM, IED, or SST. There was a weak positive correlation between symptom severity and test errors on SWM and IED in both OCD and BDD groups; increased clinical severity was associated with more errors in these tests. Furthermore, there was a negative correlation between symptom severity and SST in the BDD group.

CONCLUSIONS

Patients with BDD or OCD did not differ from healthy control subjects in terms of test performance; however, there were several statistically significant correlations between symptom severity and performance in those with BDD or OCD. More studies on EFs in BDD and OCD are required to elucidate if there are differences in EFs between these two disorders.

Working memory updating in individuals with bipolar and unipolar depression: fMRI study

Understanding neurobiological characteristics of cognitive dysfunction in distinct psychiatric disorders remains challenging. In this secondary data analysis, we examined neurobiological differences in brain response during working memory updating among individuals with bipolar disorder (BD), those with unipolar depression (UD), and healthy controls (HC). Individuals between 18-45 years of age with BD (n = 100), UD (n = 109), and HC (n = 172) were scanned using fMRI while performing 0-back (easy) and 2-back (difficult) tasks with letters as the stimuli and happy, fearful, or neutral faces as distractors. The 2(n-back) × 3(groups) × 3(distractors) ANCOVA examined reaction time (RT), accuracy, and brain activation during the task. HC showed more accurate and faster responses than individuals with BD and UD. Difficulty-related activation in the prefrontal, posterior parietal, paracingulate cortices, striatal, lateral occipital, precuneus, and thalamic regions differed among groups. Individuals with BD showed significantly lower difficulty-related activation differences in the left lateral occipital and the right paracingulate cortices than those with UD. In individuals with BD, greater difficulty-related worsening in accuracy was associated with smaller activity changes in the right precuneus, while greater difficulty-related slowing in RT was associated with smaller activity changes in the prefrontal, frontal opercular, paracingulate, posterior parietal, and lateral occipital cortices. Measures of current depression and mania did not correlate with the difficulty-related brain activation differences in either group. Our findings suggest that the alterations in the working memory circuitry may be a trait characteristic of reduced working memory capacity in mood disorders. Aberrant patterns of activation in the left lateral occipital and paracingulate cortices may be specific to BD.

The role of prefrontal cortex in cognitive control and executive function

Concepts of cognitive control (CC) and executive function (EF) are defined in terms of their relationships with goal-directed behavior versus habits and controlled versus automatic processing, and related to the functions of the prefrontal cortex (PFC) and related regions and networks. A psychometric approach shows unity and diversity in CC constructs, with 3 components in the most commonly studied constructs: general or common CC and components specific to mental set shifting and working memory updating. These constructs are considered against the cellular and systems neurobiology of PFC and what is known of its functional neuroanatomical or network organization based on lesioning, neurochemical, and neuroimaging approaches across species. CC is also considered in the context of motivation, as "cool" and "hot" forms. Its Common CC component is shown to be distinct from general intelligence (g) and closely related to response inhibition. Impairments in CC are considered as possible causes of psychiatric symptoms and consequences of disorders. The relationships of CC with the general factor of psychopathology (p) and dimensional constructs such as impulsivity in large scale developmental and adult populations are considered, as well as implications for genetic studies and RDoC approaches to psychiatric classification.

Animal Models of ADHD?

To describe animals that express abnormal behaviors as a model of Attention-Deficit Hyperactivity Disorder (ADHD) implies that the abnormalities are analogous to those expressed by ADHD patients. The diagnostic features of ADHD comprise inattentiveness, impulsivity, and hyperactivity and so these behaviors are fundamental for validation of any animal model of this disorder. Several experimental interventions such as neurotoxic lesion of neonatal rats with 6-hydroxydopamine (6-OHDA), genetic alterations, or selective inbreeding of rodents have produced animals that express each of these impairments to some extent. This article appraises the validity of claims that these procedures have produced a model of ADHD, which is essential if they are to be used to investigate the underlying cause(s) of ADHD and its abnormal neurobiology.

Multimethod Assessment of Attention, Executive Functions, and Motor Skills in Children With and Without ADHD: Children's Performance and Parents' Perceptions

Objective: We examined whether children with attention-deficit/hyperactivity disorder (ADHD) differ from children without ADHD in attention, executive functions, and motor skills and whether measures of parents' perceptions and children's performance reveal comparable results. Method: About 52 children with ADHD and 52 children without ADHD aged 6 to 13 years completed performance-based measures of attention, executive functions, and motor skills. Parents completed questionnaires to rate their children's skills. Results: Parent questionnaires but not performance-based measures revealed higher inattention and lower executive function skills in children with ADHD compared to controls. For motor skills, both measurement methods revealed lower mean values and a higher number of children showing an impairment in the ADHD group. Parent-reported difficulties but not performance-based measures were related to the presence of an ADHD diagnosis. Conclusion: Our findings suggest that considering both parent questionnaires and performance-based measures will lead to a comprehensive picture of a child's strengths and difficulties.

Deconstructing Cognitive Heterogeneity in Puerto Rican Spanish-Speaking Children With ADHD

OBJECTIVE

There is limited understanding of the cognitive profiles of Spanish-speaking children with Attention-Deficit/Hyperactivity Disorder (ADHD). The current study investigated the cognitive cluster profiles of Puerto Rican Spanish-speaking children with ADHD using the Wechsler Intelligence Scales for Children-Fourth Edition Spanish (WISC-IV Spanish) Index scores and examined the association between cognitive cluster profiles with other potentially relevant factors.

METHOD

Hierarchical cluster analysis was used to identify WISC-IV clusters in a sample of 165 Puerto Rican children who had a primary diagnosis of ADHD. To examine the validity of the ADHD clusters, analysis of variances and chi-square analyses were conducted to compare the clusters across sociodemographics (e.g., age and education), type of ADHD diagnosis (ADHD subtype, Learning Disorder comorbidity), and academic achievement.

RESULTS

Clusters were differentiated by level and pattern of performance. A five-cluster solution was identified as optimal that included (C1) multiple cognitive deficits, (C2) processing speed deficits, (C3) generally average performance, (C4) perceptual reasoning strengths, and (C5) working memory deficits. Among the five clusters, the profile with multiple cognitive deficits was characterized by poorer performance on the four WISC-IV Spanish Indexes and was associated with adverse sociodemographic characteristics.

CONCLUSIONS

Results illustrate that there is substantial heterogeneity in cognitive abilities of Puerto Rican Spanish-speaking children with ADHD, and this heterogeneity is associated with a number of relevant outcomes.

Receiver Operating Characteristic Curve Analysis of Screening Tools for Bipolar Disorder Comorbid With ADHD in Schoolchildren

Objective: We compared Child Behavior Checklist (CBCL)-AAA (Attention Problems, Aggressive Behavior, and Anxious/Depressed) and Parent-Young Mania Rating Scale (P-YMRS) profiles in Brazilian children with ADHD, pediatric-onset bipolar disorder (PBD), and PBD + ADHD. Method: Following analyses of variance or Kruskal-Wallis tests with multiple-comparison Least Significant Difference (LSD) or Dunn's Tests, thresholds were determined by Mann-Whitney U Tests and receiver operating characteristic (ROC) plots. Results: Relative to ADHD, PBD and PBD + ADHD groups scored higher on the Anxious/Depressed, Thought Problems, Rule-Breaking, and Aggressive Behavior subscales and Conduct/Delinquency Diagnostic Scale of the CBCL; all three had similar attention problems. The PBD and PBD + ADHD groups scored higher than the ADHD and healthy control (HC) groups on all CBCL problem scales. The AAA-profile ROC had good diagnostic prediction of PBD + ADHD. PBD and PBD-ADHD were associated with (similarly) elevated P-YMRS scores. Conclusion: The CBCL-PBD and P-YMRS can be used to screen for manic behavior and assist in differential diagnosis.

Enhanced switching and familial susceptibility for psychosis

INTRODUCTION

Working Memory and Task-Switching are essential components of cognitive control, which underlies many symptoms evident across multiple neuropsychiatric disorders, including psychotic and mood disorders. Vulnerability to these disorders has a substantial genetic component, suggesting that clinically unaffected first-degree relatives may carry some vulnerability-related traits. Converging evidence from animal and human studies demonstrates that dopamine transmission, striatal and frontal brain regions, and attention and switching behaviors are essential components of a multilevel circuit involved in salience, and disruptions in that circuit may lead to features of psychosis. Yet, it is possible that unaffected relatives may also possess characteristics that protect against development of illness. We hypothesized that reduced switch cost in a cued task-switching task, may be a behavioral expression of this "resilience" phenotype that will be observable in unaffected relatives.

METHODS

We tested a large community sample (n = 536) via the web, to assess different subcomponents of cognitive control, including task-switching and working memory, as well as risk-taking, among individuals who report having an affected relative with a psychotic or mood disorder.

RESULTS

Healthy individuals with suspected genetic risk due to a self-reported familial history of a psychotic disorder demonstrated better task-switching performance compared to healthy people without a psychiatrically ill relative and those with a relative with a mood disorder. This result was specific to illness status and task domain, in that individuals with a personal history of depression or anxiety did not show improved task-switching performance, and this improvement was selective to task-switching and not seen in other putative cognitive control domains (working memory or risk taking).

CONCLUSIONS

Although this study has limitations and independent replication is needed, these preliminary findings suggest a potential avenue for understanding susceptibility to these disorders by highlighting possible protective as well as vulnerability-related aspects of risk phenotypes.

Decreased functional connectivity in the fronto-parietal network in children with mood disorders compared to children with dyslexia during rest: An fMRI study

Background

The DSM-5 separates the diagnostic criteria for mood and behavioral disorders. Both types of disorders share neurocognitive deficits of executive function and reading difficulties in childhood. Children with dyslexia also have executive function deficits, revealing a role of executive function circuitry in reading. The aim of the current study is to determine whether there is a significant relationship of functional connectivity within the fronto-parietal and cingulo-opercular cognitive control networks to reading measures for children with mood disorders, behavioral disorders, dyslexia, and healthy controls (HC).

Method

Behavioral reading measures of phonological awareness, decoding, and orthography were collected. Resting state fMRI data were collected, preprocessed, and then analyzed for functional connectivity. Differences in the reading measures were tested for significance among the groups. Global efficiency (GE) measures were also tested for correlation with reading measures in 40 children with various disorders and 17 HCs.

Results

Significant differences were found between the four groups on all reading measures. Relative to HCs and children with mood disorders or behavior disorders, children with dyslexia as a primary diagnosis scored significantly lower on all three reading measures. Children with mood disorders scored significantly lower than controls on a test of phonological awareness. Phonological awareness deficits correlated with reduced resting state functional connectivity MRI (rsfcMRI) in the cingulo-opercular network for children with dyslexia. A significant difference was also found in fronto-parietal global efficiency in children with mood disorders relative to the other three groups. We also found a significant difference in cingulo-opercular global efficiency in children with mood disorders relative to the Dyslexia and Control groups. However, none of these differences correlate significantly with reading measures.

Conclusions/significance

Reading difficulties involve abnormalities in different cognitive control networks in children with dyslexia compared to children with mood disorders. Findings of the current study suggest increased functional connectivity of one cognitive control network may compensate for reduced functional connectivity in the other network in children with mood disorders. These findings provide guidance to clinical professionals for design of interventions tailored for children suffering from reading difficulties originating from different pathologies.

Increased reward-oriented impulsivity in older bipolar patients: A preliminary study

OBJECTIVE

Impulsivity is a well-established trait of bipolar disorder (BD) that persists across mood phases. It is, however, still unknown whether, in BD, impulsivity remains stable or varies in intensity over the lifespan. This cross-sectional study compared impulsive behavior in older euthymic BD patients and healthy individuals using a range of self-rating and behavioral measures of impulsivity.

METHODS

28 BD patients (56.07 ± 4.08 years, 16 women) and 15 healthy controls (HC; 55.1 ± 3.95 years, 6 women) were administered the Barratt Impulsivity Scale (BIS) and selected tasks of the Cambridge Neuropsychological Test Automated Batter (CANTAB) reflecting impulsivity. Multivariate analysis of variance controlled for age compared impulsivity measures across BD and HC.

RESULTS

BD patients displayed poor decision making, risk taking, and increased delay aversion. Other measures of impulsivity such as response inhibition, sustained cognitive control, and BIS scores were, overall, comparable between BD and HC.

CONCLUSIONS

These preliminary findings suggest that, in BD, aspects of impulsivity related to reward-based decision making persist into late adulthood. Large scale, longitudinal studies are needed to evaluate the relationship of age to impulsivity over time, and explore the link between impulsivity and illness progression in elderly individuals with BD.

Are self-rated and behavioural measures of impulsivity in bipolar disorder mainly related to comorbid substance use problems?

INTRODUCTION

Impulsivity is a multidimensional feature observed in bipolar disorder (BD) and substance use disorder (SUD). We previously found a relationship between SUD and risk taking in BD. It is still unclear whether self-rated and behavioral impulsivity measures differ between BD with and without comorbid SUD, or are specific to BD.

METHODS

93 adults with BD with comorbid SUD, 91 BD without SUD, and 93 healthy controls (HC) were administered the Barratt Impulsivity Scale (BIS), the Behavioral Inhibition/Behavioral Activation System Scale (BIS/BAS), and the Cambridge Neuropsychological Test Automated Battery. Analyses compared impulsivity measures across groups controlling for age. Discriminant function analyses (DFA) assessed the combination of variables effectively predicting group membership.

RESULTS

BD displayed increased BIS, BIS/BAS scores, reduced performance on the Cambridge Gambling and Rapid Visual Processing, and Affective Go/No-Go tasks compared to HC. Comparisons between BD with and without SUD showed increased BIS Motor impulsiveness. The overall predictive power of DFA was weak.

CONCLUSIONS

Some facets of impulsivity are a core trait of BD and are partially independent from the presence of SUD. Motor impulsiveness may be distinctive of BD+SUD. More research is needed to understand the role of impulsive behaviors as risk factors for relapse in SUD.

Prefrontal oxygenation during verbal fluency and cognitive function in adolescents with bipolar disorder type II

Evaluation of depressive states in children can be challenging. Most of the studies that have investigated cognitive function and cerebral blood volume changes using functional MRI (fMRI) in bipolar disorder (BD) have been confined to BDI or heterogeneous cohorts with attention-deficit/hyperactivity disorder (ADHD). This study investigated cognitive functions in adolescents with BDII and without ADHD using near-infrared spectroscopy (NIRS) and a Das-Naglieri Cognitive Assessment System (DN-CAS). Ten patients with BDII and without ADHD symptoms and 10 age- and gender-matched healthy controls were enrolled in the present study. NIRS was used to detect hemoglobin concentration changes during a verbal fluency test (VFT). In addition, the DN-CAS was used to evaluate cognitive function in four domains: planning, attention, simultaneous, and successive processing. Significant differences between the BDII and control groups in [oxy-Hb] changes during the early phase of VFT were observed in the lower prefrontal cortex but not in cognitive functioning. Furthermore, there was a significant correlation between planning and attention scores in BD subjects.

Structure of the Wechsler Intelligence Scale for Children - Fourth Edition in a Group of Children with ADHD

Objective: This study used confirmatory factor analysis to examine the factor structure for the 10 core WISC–IV subtests in a group of children (N = 812) with ADHD.

Method: The study examined oblique four- and five-factor models, higher order models with one general secondary factor and four and five primary factors, and a bifactor model with a general factor and four specific factors.

Results: The findings supported all models tested, with the bifactor model being the optimum model. For this model, only the general factor had high explained common variance and omega hierarchical value, and it predicted reading and arithmetic abilities.

Conclusion: The findings favor the use of the FSIQ scores of the WISC-IV, but not the subscale index scores.

Editorial Perspective: How to optimise frequency band neurofeedback for ADHD

Attention deficit/hyperactivity disorder (ADHD) is one of the most prevalent paediatric neuropsychiatric disorders and is characterised by hyperactivity, inattention and increased impulsivity. Children with ADHD are often also characterised by deficits in a variety of cognitive domains, including problems in working memory, a generally slower and more variable style of information processing and deficits in temporal processing, inhibitory functions and delay processing. Overarching executive functions like information updating, response inhibition and mental set shifting are also impaired in many, but not all, children with ADHD, demonstrating the neuropsychological heterogeneity characterising this disorder. Deficits in executive functions can persist into adulthood and have a substantial negative impact on everyday life. A variety of approaches are commonly considered for the treatment of ADHD (including pharmacological interventions, patient-centred cognitive-behavioural therapy approaches and specific teacher/parent training programmes). More recently, adding to this multimodal treatment approach, neurofeedback has grown in popularity as an intervention option for patients with ADHD. This article considers this intervention approach and the opportunities for optimising treatment for executive control dysfunctions in ADHD using theta/beta neurofeedback.

Differences in the performance of NK1R-/- ('knockout') and wildtype mice in the 5‑Choice Continuous Performance Test

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We compared the behaviour of NK1R−/− mice and wildtypes in the 5-Choice Continuous Performance Test.

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NK1R−/− mice did not express excess impulsivity (premature response or false alarms) in this test.

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NK1R−/− mice expressed excessive perseveration, which is common in ADHD.

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The findings point to a behavioural phenotype for ADHD patients with polymorphism of the TACR1 gene.

Mice lacking functional NK1 (substance P-preferring) receptors typically display excessive inattentiveness (omission errors) and impulsivity (premature responses) when compared with wildtypes in the 5-Choice Serial Reaction-Time Test (5-CSRTT). These abnormal behaviours are analogous to those seen in humans suffering from Attention Deficit Hyperactivity Disorder (ADHD). Here we used the 5-Choice Continuous‑Performance Test (5C-CPT) to ascertain whether NK1R−/− mice also display excessive false alarms (an inappropriate response to a ‘no-go’ signal), which is another form of impulsive behaviour. NK1R−/− mice completed more trials than wildtypes, confirming their ability to learn and carry out the task. At the start of Stage 1 of training, but not subsequently, they also scored more premature responses than wildtypes. When the mice were tested for the first time, neither false alarms nor premature responses was higher in NK1R−/− mice than wildtypes but, as in the 5-CSRTT, the latter behaviour was strongly dependent on time of day. NK1R−/− mice expressed excessive perseveration during all stages of the 5C-CPT. This behaviour is thought to reflect compulsive checking, which is common in ADHD patients. These findings point to differences in the 5-CSRTT and 5C-CPT protocols that could be important for distinguishing why the cognitive performance and response control of NK1R−/− mice differs from their wildtypes. The results further lead to the prediction that ADHD patients with polymorphism of the TACR1 gene (the human equivalent of Nk1r) would express more perseveration, but not false alarms, in Continuous Performance Tests when compared with other groups of subjects.

Ongoing behavioral state information signaled in the lateral habenula guides choice flexibility in freely moving rats

The lateral habenula (LHb) plays a role in a wide variety of behaviors ranging from maternal care, to sleep, to various forms of cognition. One prominent theory with ample supporting evidence is that the LHb serves to relay basal ganglia and limbic signals about negative outcomes to midbrain monoaminergic systems. This makes it likely that the LHb is critically involved in behavioral flexibility as all of these systems have been shown to contribute when flexible behavior is required. Behavioral flexibility is commonly examined across species and is impaired in various neuropsychiatric conditions including autism, depression, addiction, and schizophrenia; conditions in which the LHb is thought to play a role. Therefore, a thorough examination of the role of the LHb in behavioral flexibility serves multiple functions including understanding possible connections with neuropsychiatric illnesses and additional insight into its role in cognition in general. Here, we assess the LHb’s role in behavioral flexibility through comparisons of the roles its afferent and efferent pathways are known to play. Additionally, we provide new evidence supporting the LHb contributions to behavioral flexibility through organization of specific goal directed actions under cognitively demanding conditions. Specifically, in the first experiment, a majority of neurons recorded from the LHb were found to correlate with velocity on a spatial navigation task and did not change significantly when reward outcomes were manipulated. Additionally, measurements of local field potential (LFP) in the theta band revealed significant changes in power relative to velocity and reward location. In a second set of experiments, inactivation of the LHb with the gamma-aminobutyric acid (GABA) agonists baclofen and muscimol led to an impairment in a spatial/response based repeated probabilistic reversal learning task. Control experiments revealed that this impairment was likely due to the demands of repeated switching behaviors as rats were unimpaired on initial discrimination acquisition or retention of probabilistic learning. Taken together, these novel findings compliment other work discussed supporting a role for the LHb in action selection when cognitive or emotional demands are increased. Finally, we discuss future mechanisms by which a superior understanding of the LHb can be obtained through additional examination of behavioral flexibility tasks.

Affective processing bias in youth with primary bipolar disorder or primary attention-deficit/hyperactivity disorder

High rates of comorbidity and overlapping diagnostic criteria between pediatric bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) contribute to diagnostic and treatment confusion. To advance what is known about both disorders, we compared effect of emotional stimuli on response control in children with primary BD, primary ADHD and typically developing controls (TDC). Participants included 7-17 year olds with either "narrow-phenotype" pediatric BD (n = 25), ADHD (n = 25) or TDC (n = 25). Groups were matched on participant age and FSIQ. The effect of emotional stimuli on response control was assessed using the Cambridge Neuropsychological Test Automated Battery Affective Go/No-Go task (CANTAB AGN). We found a group by target valence interaction on commission errors [F(2,71) = 5.34, p < 0.01, ƞ p (2) = 0.13] whereby ADHD, but not TDC participants, made more errors on negative than positive words [t(24) = -2.58, p < 0.05, r = 0.47]. In contrast, there was a nonsignificant trend for BD participants to make fewer errors on negative versus positive words compared to ADHD and TDC participants. Between-subjects effects showed that ADHD participants made more errors than TDC, but not BD participants. Our main finding advances what is known about the effect of emotional stimuli on response control in children with ADHD. Our results suggesting a positive affective processing bias in children with ADHD compliment emerging literature show that difficulties with emotional processing and regulation may be core features of ADHD. Further, given the observed pattern of results in children with ADHD compared to BD children, our behavioral results suggest the importance of examining differences in the brain-behavior mechanisms involved in affective processing in children with ADHD compared to BD children.

Intrinsic brain indices of verbal working memory capacity in children and adolescents

Working memory (WM) is central to the acquisition of knowledge and skills throughout childhood and adolescence. While numerous behavioral and task-based functional magnetic resonance imaging (fMRI) studies have examined WM development, few have used resting-state fMRI (R-fMRI). Here, we present a systematic R-fMRI examination of age-related differences in the neural indices of verbal WM performance in a cross-sectional pediatric sample (ages: 7-17; n=68), using data-driven approaches. Verbal WM capacity was measured with the digit span task, a commonly used educational and clinical assessment. We found distinct neural indices of digit span forward (DSF) and backward (DSB) performance, reflecting their unique neuropsychological demands. Regardless of age, DSB performance was related to intrinsic properties of brain areas previously implicated in attention and cognitive control, while DSF performance was related to areas less commonly implicated in verbal WM storage (precuneus, lateral visual areas). From a developmental perspective, DSF exhibited more robust age-related differences in brain-behavior relationships than DSB, and implicated a broader range of networks (ventral attention, default, somatomotor, limbic networks)--including a number of regions not commonly associated with verbal WM (angular gyrus, subcallosum). These results highlight the importance of examining the neurodevelopment of verbal WM and of considering regions beyond the "usual suspects".

Latent profile analysis of working memory performance in a sample of children with ADHD

The current study used latent profile analysis (LPA) to ascertain distinct groups of children with ADHD (N = 701) in terms of performance on working memory (WM) tasks that tapped visuospatial sketchpad, spatial central executive, and verbal central executive functions. It compared the WM performances of these classes with a clinical comparison group (N = 59). The participants' age ranged from 7 to 16 years (586 males, 71 females). The results of the LPA supported three classes. For all three WM tasks, class 1 (N = 196) had more difficulties than classes 2 (N = 394) and 3 (N = 111), and the clinical comparison group. Class 2 had more difficulties than class 3 and the clinical comparison group, and there was no difference between class 3 and the clinical comparison group. Class 1 had lower IQ and academic abilities, and relatively more individuals with depressive disorders. The implications of the findings for understanding ADHD and its treatment are discussed.

How Informative Is the CANTAB to Assess Executive Functioning in Children With ADHD? A Controlled Study

OBJECTIVE

The authors examined the utility of the computerized Cambridge Neuropsychological Test Automated Battery (CANTAB) to evaluate executive functioning deficits in children with ADHD.

METHOD

Participants were unmedicated children and adolescents with (n = 107) and without (n = 45) Diagnostic and Statistical Manual of Mental Disorders (4th ed.) ADHD. The authors administered the CANTAB Eclipse battery, which comprises specific tasks shown to be deficient in individuals with ADHD.

RESULTS

With the exception of the affective go/no-go total omissions, ADHD participants were significantly more impaired on all other subtests of the CANTAB in comparison with controls. Effect sizes for individual CANTAB tests were largely in the medium range with the largest effect sizes seen in spatial working memory total and between errors.

CONCLUSION

These CANTAB results are highly congruent with those reported in studies using traditional neuropsychological testing batteries, supporting the utility of the CANTAB to assess neuropsychological deficits in children with ADHD in clinical and research settings.

Advancing understanding of executive function impairments and psychopathology: bridging the gap between clinical and cognitive approaches

Executive function (EF) is essential for successfully navigating nearly all of our daily activities. Of critical importance for clinical psychological science, EF impairments are associated with most forms of psychopathology. However, despite the proliferation of research on EF in clinical populations, with notable exceptions clinical and cognitive approaches to EF have remained largely independent, leading to failures to apply theoretical and methodological advances in one field to the other field and hindering progress. First, we review the current state of knowledge of EF impairments associated with psychopathology and limitations to the previous research in light of recent advances in understanding and measuring EF. Next, we offer concrete suggestions for improving EF assessment. Last, we suggest future directions, including integrating modern models of EF with state of the art, hierarchical models of dimensional psychopathology as well as translational implications of EF-informed research on clinical science.

Attention-based classification pattern, a research domain criteria framework, in youths with bipolar disorder and attention-deficit/hyperactivity disorder

OBJECTIVE

The National Institute of Mental Health has initiated the Research Domain Criteria (RDoC) project. Instead of using disorder categories as the basis for grouping individuals, the RDoC suggests finding relevant dimensions that can cut across traditional disorders. Our aim was to use the RDoC's framework to study patterns of attention deficit based on results of Conners' Continuous Performance Test (CPT II) in youths diagnosed with bipolar disorder (BD), attention-deficit/hyperactivity disorder (ADHD), BD+ADHD and controls.

METHOD

Eighteen healthy controls, 23 patients with ADHD, 10 with BD and 33 BD+ADHD aged 12-17 years old were assessed. Pattern recognition was used to partition subjects into clusters based simultaneously on their performance in all CPT II variables. A Fisher's linear discriminant analysis was used to build a classifier.

RESULTS

Using cluster analysis, the entire sample set was best clustered into two new groups, A and B, independently of the original diagnoses. ADHD and BD+ADHD were divided almost 50% in each subgroup, and there was an agglomeration of controls and BD in group B. Group A presented a greater impairment with higher means in all CPT II variables and lower Children's Global Assessment Scale. We found a high cross-validated classification accuracy for groups A and B: 95.2%. Variability of response time was the strongest CPT II measure in the discriminative pattern between groups A and B.

CONCLUSION

Our classificatory exercise supports the concept behind new approaches, such as the RDoC framework, for child and adolescent psychiatry. Our approach was able to define clinical subgroups that could be used in future pathophysiological and treatment studies.

Neurocognitive impairments among youth with pediatric bipolar disorder: a systematic review of neuropsychological research

BACKGROUND

Pediatric bipolar disorder (PBD) has emerged as a field of research in which neuropsychological studies are continuously providing new empirical findings. Despite this, a comprehensive framework for neurocognitive impairments is still lacking, and most of the evidence remains unconnected. We addressed this question through a systematic review of neuropsychological research, with the aim of elucidating the main issues concerning this topic.

METHOD

A comprehensive search of databases (PubMed, PsycINFO) was performed. Published manuscripts between 1990 and January 2014 were identified. Overall, 124 studies fulfilled inclusion criteria. Methodological differences between studies required a descriptive review of findings.

RESULTS

Evidence indicates that verbal/visual-spatial memory, processing speed, working memory, and social cognition are neurocognitive domains impaired in PBD youth. Furthermore, these deficits are greater among those who suffer acute affective symptoms, PBD type I, and/or attention deficit hyperactivity disorder (ADHD) comorbidity. In addition, several neurocognitive deficits imply certain changes in prefrontal cortex activity and are somewhat associated with psychosocial and academic disabilities. Strikingly, these deficits are consistently similar to those encountered in ADHD as well as severe mood dysregulation (SMD). Besides, some neurocognitive impairments appear before the onset of the illness and tend to maintain stable across adolescence. Finally, any therapy has not yet demonstrated to be effective on diminishing these neurocognitive impairments.

LIMITATIONS

More prolonged follow-up studies aimed at delineating the course of treatment and the response to it are warranted.

CONCLUSIONS

Despite noteworthy research on the neurocognitive profile of PBD, our knowledge is still lagging behind evidence from adult counterparts.

Obsessive-compulsive disorder is associated with broad impairments in executive function: A meta-analysis

Obsessive-compulsive disorder (OCD) is a serious and often chronically disabling condition. The current dominant model of OCD focuses on abnormalities in prefrontal-striatal circuits that support executive function (EF). While there is growing evidence for EF impairments associated with OCD, results have been inconsistent, making the nature and magnitude of these impairments controversial. The current meta-analysis uses random-effects models to synthesize 110 previous studies that compared participants with OCD to healthy control participants on at least one neuropsychological measure of EF. The results indicate that individuals with OCD are impaired on tasks measuring most aspects of EF, consistent with broad impairment in EF. EF deficits were not explained by general motor slowness or depression. Effect sizes were largely stable across variation in demographic and clinical characteristics of samples, although medication use, age, and gender moderated some effects.

Could comorbid bipolar disorder account for a significant share of executive function deficits in adults with attention-deficit hyperactivity disorder?

OBJECTIVE

The frequent comorbidity between attention-deficit hyperactivity disorder (ADHD) and bipolar disorder (BD) represents a challenge for disentangling specific impairments of each disorder in adulthood. Their functional impairments seem to be mediated by executive function deficits. However, little is known about the extent to which each executive function deficit might be disorder specific or explained by the comorbidity. The aim of the present study was to determine if comorbid BD could account for a significant share of executive function deficits when measured by the Wisconsin Card Sorting Test (WCST) in adults with ADHD.

METHODS

Adult patients with ADHD and healthy subjects were evaluated in the ADHD outpatient Program at the Hospital de Clínicas de Porto Alegre. Psychiatric diagnoses were based on DSM-IV criteria. WCST scores were compared by multivariate analysis of covariance among three groups: ADHD with BD (n = 51), ADHD without BD (n = 278), and healthy subjects (n = 91).

RESULTS

When compared to patients without BD and healthy subjects, patients with ADHD and comorbid BD showed lower scores in total correct answers (p = 0.003); higher scores in total errors (p = 0.004) and non-perseverative errors (p = 0.002); and completed fewer categories (p = 0.009). Patients with ADHD without BD did not differ from healthy subjects.

CONCLUSIONS

WCST impairments among patients with ADHD seem to be to a large extent attributable to comorbid BD. Although other executive function deficits (e.g., in the inhibitory control domain) have been demonstrated to accompany ADHD, the present findings suggest that set-shifting deficits are strongly related to comorbid BD.

Differentiating bipolar disorder from unipolar depression and ADHD: the utility of the general behavior inventory

Adolescence and early adulthood are the peak ages for the onset of unipolar and bipolar mood disorders. Moreover, for most individuals with attention-deficit/hyperactivity disorder (ADHD), symptoms and impairment begin in childhood but persist well into adolescence and adulthood (e.g., Barkley, 2010). Thus, adolescence and early adulthood represent a developmental window wherein individuals can be affected by mood disorders, ADHD, or both. Because treatment protocols for unipolar depression (UPD), bipolar disorder (BD), and ADHD are quite different, it is crucial that assessment instruments used among adolescents and young adults differentiate between these disorders. The primary objectives of this study were to evaluate the predictive and diagnostic validity of General Behavior Inventory (GBI; Depue et al., 1981) scores in discriminating BD from UPD and ADHD. Participants were drawn from adolescent (n = 361) and young adult (n = 614) samples. Based on findings from logistic regression and receiver-operating characteristics analyses, the diagnostic efficiency of the GBI scales range from fair (discriminating UPD from BD) to good (discriminating BD participants from nonclinical controls). Multilevel diagnostic likelihood ratios are also provided to facilitate individual decision making.

Elucidating poor decision-making in a rat gambling task

Although poor decision-making is a hallmark of psychiatric conditions such as attention deficit/hyperactivity disorder, pathological gambling or substance abuse, a fraction of healthy individuals exhibit similar poor decision-making performances in everyday life and specific laboratory tasks such as the Iowa Gambling Task. These particular individuals may provide information on risk factors or common endophenotypes of these mental disorders. In a rodent version of the Iowa gambling task--the Rat Gambling Task (RGT), we identified a population of poor decision makers, and assessed how these rats scored for several behavioral traits relevant to executive disorders: risk taking, reward seeking, behavioral inflexibility, and several aspects of impulsivity. First, we found that poor decision-making could not be well predicted by single behavioral and cognitive characteristics when considered separately. By contrast, a combination of independent traits in the same individual, namely risk taking, reward seeking, behavioral inflexibility, as well as motor impulsivity, was highly predictive of poor decision-making. Second, using a reinforcement-learning model of the RGT, we confirmed that only the combination of extreme scores on these traits could induce maladaptive decision-making. Third, the model suggested that a combination of these behavioral traits results in an inaccurate representation of rewards and penalties and inefficient learning of the environment. Poor decision-making appears as a consequence of the over-valuation of high-reward-high-risk options in the task. Such a specific psychological profile could greatly impair clinically healthy individuals in decision-making tasks and may predispose to mental disorders with similar symptoms.

High-throughput cognitive assessment using BrainTest.org: examining cognitive control in a family cohort

Introduction Understanding the relationship between brain and complex latent behavioral constructs like cognitive control will require an inordinate amount of data. Internet-based methods can rapidly and efficiently refine behavioral measures in very large samples that are needed for genetics and behavioral research. Cognitive control is a multifactorial latent construct that is considered to be an endophenotype in numerous neuropsychiatric disorders, including attention deficit/hyperactivity disorder (ADHD). While previous studies have demonstrated high correlations between Web- and lab-based scores, skepticism remains for its broad implementation. Methods Here, we promote a different approach by characterizing a completely Web-recruited and tested community family sample on measures of cognitive control. We examine the prevalence of attention deficit symptoms in an online community sample of adolescents, demonstrate familial correlations in cognitive control measures, and use construct validation techniques to validate our high-throughput assessment approach. Results A total of 1214 participants performed Web-based tests of cognitive control with over 200 parent-child pairs analyzed as part of the primary study aims. The data show a wide range of "subclinical" symptomatology in a web community sample of adolescents that supports a dimensional view of attention and also provide preliminary narrow-sense heritability estimates for commonly used working memory and response inhibition tests. Conclusions Finally, we show strong face and construct validity for these measures of cognitive control that generally exceeds the evidence required of new lab-based measures. We discuss these results and how broad implementation of this platform may allow us to uncover important brain-behavior relationships quickly and efficiently.

Executive deficits in early onset bipolar disorder versus ADHD: impact of processing speed and lifetime psychosis

Executive deficits are reported in both early onset bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD), and controversies regarding comorbidity and symptom overlap have complicated the research on executive function in BD. Reports of the negative impact of executive difficulties on academic functioning indicate a need for a greater focus on executive difficulties in early onset psychiatric disorders. Executive function and processing speed in youths with BD (n = 4), ADHD (n = 26) and BD + ADHD (n = 13) were compared with controls (n = 69). All clinical groups demonstrated executive impairment. The combined group was most impaired. There were no significant differences between the groups. Executive deficit in the BD group was associated with a history of psychotic symptoms. The BD-nonpsychotic group was impaired only with regard to processing speed. Processing speed adjustment improved working memory and normalized interference control in both BD and ADHD.

CONCLUSION

executive deficits in BD may be determined by a history of psychotic symptoms rather than by comorbid ADHD. Some aspects of executive problems appear speed-related.

Contextual social cognition impairments in schizophrenia and bipolar disorder

Background

The ability to integrate contextual information with social cues to generate social meaning is a key aspect of social cognition. It is widely accepted that patients with schizophrenia and bipolar disorders have deficits in social cognition; however, previous studies on these disorders did not use tasks that replicate everyday situations.

Methodology/Principal Findings

This study evaluates the performance of patients with schizophrenia and bipolar disorders on social cognition tasks (emotional processing, empathy, and social norms knowledge) that incorporate different levels of contextual dependence and involvement of real-life scenarios. Furthermore, we explored the association between social cognition measures, clinical symptoms and executive functions. Using a logistic regression analysis, we explored whether the involvement of more basic skills in emotional processing predicted performance on empathy tasks. The results showed that both patient groups exhibited deficits in social cognition tasks with greater context sensitivity and involvement of real-life scenarios. These deficits were more severe in schizophrenic than in bipolar patients. Patients did not differ from controls in tasks involving explicit knowledge. Moreover, schizophrenic patients’ depression levels were negatively correlated with performance on empathy tasks.

Conclusions/Significance

Overall performance on emotion recognition predicted performance on intentionality attribution during the more ambiguous situations of the empathy task. These results suggest that social cognition deficits could be related to a general impairment in the capacity to implicitly integrate contextual cues. Important implications for the assessment and treatment of individuals with schizophrenia and bipolar disorders, as well as for neurocognitive models of these pathologies are discussed.

Deficits in emotion recognition in pediatric bipolar disorder: the mediating effects of irritability

BACKGROUND

Pediatric Bipolar Disorder (PBD) is a debilitating condition associated with impairment in many domains. Social functioning is one of the disorder's most notable areas of impairment and this deficit may be in part due to difficulties recognizing affect in others.

METHODS

In the present study, medication naïve youth with PBD were compared to age-matched healthy controls on their ability to (a) distinguish between categorical emotions, such as happiness, anger, and sadness on the Emotion Recognition Test (ER-40) and (b) differentiate between levels of emotional intensity on an adapted version of the Penn Emotional Acuity Task (Chicago-PEAT).

RESULTS

Results indicated that PBD youth misidentified sad, fearful, and neutral faces more often than controls, and PBD girls mislabeled 'very angry' faces more often than healthy girls. A mediation analyses indicated that these diagnostic group differences on emotion recognition were significantly mediated by irritability.

LIMITATIONS

The Chicago-PEAT only examined variations in emotional intensity for the emotions happy and anger. Additionally, all results are correlational; therefore causal inferences cannot be made.

CONCLUSIONS

Supporting previous literature, the present findings highlight the importance of emotion recognition deficits in PBD individuals. Additionally, the irritability associated with PBD may be an important mechanism of this deficit and may thus represent an important target for treatment.

An update on the debated association between ADHD and bipolar disorder across the lifespan

Diagnostic formulations for attention deficit hyperactivity disorder (ADHD) and bipolar disorder (BD) both include symptoms of distractibility, psychomotor agitation and talkativeness, alongside associated emotional features (irritability and emotional lability). Treatment studies suggest the importance of accurate delineation of ADHD and BD. However, boundaries between the two disorders are blurred by the introduction of broader conceptualisations of BD. This review attempts to elucidate whether associations between ADHD and BD are likely to be driven by superficial symptomatological similarities or by a more meaningful etiological relationship between the disorders. This is achieved by outlining findings on comorbidity, temporal progression of the disorders, familial co-variation, and neurobiology in ADHD and BD across the lifespan. Longitudinal studies fail to consistently show developmental trajectories between ADHD and BD. Comparative research investigating neurobiology is in its infancy, and although some similarities are seen between ADHD and BD, studies also emphasise differences between the two disorders. However, comorbidity and family studies appear to show that the two disorders occur together and aggregate in families at higher than expected rates. Furthermore close inspection of results from population studies reveals heightened co-occurrence of ADHD and BD even in the context of high comorbidity commonly noted in psychopathology. These results point towards a meaningful association between ADHD and BD, going beyond symptomatic similarities. However, future research needs to account for heterogeneity of BD, making clear distinctions between classical episodic forms of BD, and broader conceptualisations of the disorder characterised by irritability and emotional lability, when evaluating the relationship with ADHD.

An association between affective lability and executive functioning in bipolar disorder

Studies suggest altered affect regulation manifested by affective lability in manic/mixed and euthymic states in patients with bipolar disorder (BD). Altered affect regulation may arise from disturbances in interactions between the cognitive and the emotional brain networks. However, the relationship between affective lability and executive function has not previously been studied. Our aim was to investigate affective lability, as measured with the Affective Lability Scale (ALS) in patients with BD (N=32) compared to healthy controls (HC) (N=60), and its relationship to executive functioning. We found significantly higher ALS scores in the BD than in the HC group, indicating a higher degree of affective lability in patients with BD. Sub-sample analysis revealed a significant positive relationship between affective lability and semantic set shifting abilities in BD only. These findings suggest that higher levels of affective lability compared with controls are a trait as well as state dependent in BD, and that disturbed affective lability may arise from an aberrant interaction between cognitive and emotional brain networks.

Are executive function and impulsivity antipodes? A conceptual reconstruction with special reference to addiction

RATIONALE

Although there is considerable interest in how either executive function (EF) or impulsivity relate to addiction, there is little apparent overlap between these research areas.

OBJECTIVES

The present paper aims to determine if components of these two constructs are conceptual antipodes--widely separated on a shared continuum.

METHODS

EFs and impulsivities were compared and contrasted. Specifically, the definitions of the components of EF and impulsivity, the methods used to measure the various components, the populations of drug users that show deficits in these components, and the neural substrates of these components were compared and contrasted.

RESULTS

Each component of impulsivity had an antipode in EF. EF, however, covered a wider range of phenomena, including compulsivity.

CONCLUSIONS

Impulsivity functions as an antipode of certain components of EF. Recognition of the relationship between EF and impulsivity may inform the scientific inquiry of behavioral problems such as addiction. Other theoretical implications are discussed.