Neuropsychological functioning in youth with bipolar disorder

Enhanced working and verbal memory after lamotrigine treatment in pediatric bipolar disorder

OBJECTIVE

To examine the treatment impact of lamotrigine on the neurocognitive profile of patients with pediatric bipolar disorder (PBD).

METHOD

Healthy controls (HC) (n = 24; mean age = 12.4 +/- 3.3 years) and unmedicated PBD patients with manic, mixed, or hypomanic episodes (n = 34; mean age = 13 +/- 3.1 years) were matched for IQ, age, sex, race, and socioeconomic status. A neurocognitive battery was administered at baseline and again after 14 weeks, during which PBD patients were treated with lamotrigine.

RESULTS

Clinical symptoms improved with treatment in the patient group with significant change from baseline to follow-up on the Young Mania Rating Scale (p < 0.001) and the Children's Depression Rating Scale-Revised (p < 0.001). Global neurocognitive function improved with lamotrigine in PBD patients over time relative to that in HC, although overall performance remained impaired. Working memory and verbal memory significantly improved with treatment in patients, and deficits in these domains were no longer significantly impaired relative to HC at follow-up. Executive function significantly improved with treatment in the patient group but still lagged behind HC at follow-up. Performance on attention tests did not improve with treatment.

CONCLUSIONS

There appears to be significant improvement in cognitive abilities in PBD patients treated with lamotrigine that is most prominent in the areas of working memory and verbal memory and that occurs along with mood stabilization.

Molecular genetics of attention deficit hyperactivity disorder

Although twin studies demonstrate that ADHD is a highly heritable condition, molecular genetic studies suggest that the genetic architecture of ADHD is complex. The handful of genome-wide linkage and association scans that have been conducted thus far show divergent findings and are, therefore, not conclusive. Similarly, many of the candidate genes reviewed here (ie, DBH, MAOA, SLC6A2, TPH-2, SLC6A4, CHRNA4, GRIN2A) are theoretically compelling from neurobiological systems perspective but available data are sparse and inconsistent. However, candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder, with meta-analyses supportive of a role of the genes coding for DRD4, DRD5, SLC6A3, SNAP-25, and HTR1B in the etiology of ADHD.

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

Often, there is diagnostic confusion between bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD) in youth due to similar behavioral presentations. Both disorders have been implicated as having abnormal functioning in the prefrontal cortex; however, there may be subtle differences in the manner in which the prefrontal cortex functions in each disorder that could assist in their differentiation. Executive function is a construct thought to be a behavioral analogy to prefrontal cortex functioning. We provide a qualitative review of the literature on performance on executive function tasks for BD and ADHD in order to determine differences in task performance and neurocognitive profile. Our review found primary differences in executive function in the areas of interference control, working memory, planning, cognitive flexibility, and fluency. These differences may begin to establish a pediatric BD profile that provides a more objective means of differential diagnosis between BD and ADHD when they are not reliably distinguished by clinical diagnostic methods.

Neural correlates of response inhibition in pediatric bipolar disorder

OBJECTIVES

Pediatric bipolar disorder is characterized by core deficits in mood and executive function and commonly co-occurs with attention-deficit/hyperactivity disorder (ADHD). We aimed to examine response inhibition in this population, as an element of executive function, which, if aberrant, may interfere with learning and information processing.

METHODS

Children (9-18 years) with bipolar I or II disorder (BD, n = 26) and age, gender, and intelligence quotient (IQ) comparable healthy children (HC, n = 22) without any psychopathology were given a standardized Go/NoGo computerized task measuring response inhibition. A whole-brain functional magnetic resonance imaging (MRI) group analysis was performed using statistical parametric mapping software (SPM2) for comparing NoGo to Go epochs.

RESULTS

There were no statistically significant group differences between groups in age, gender, or ethnicity. The BD group had high rates of co-morbid disorders, including 81% with ADHD, 62% with oppositional defiant disorder (ODD), and 46% with anxiety disorders. This BD group had fewer correct responses on Go (84% vs. 96%, T[46] = 3.35, p = 0.002) and overall (85% vs. 94%, T[46] = 4.12, p = 0.0002) trials as compared to the HC group. However, there were no statistically significant group differences in response inhibition on NoGo trials (p = 0.11). In the NoGo-Go contrast, the BD group showed increased neural activation in the right dorsolateral prefrontal cortex (DLPFC) compared to HC (T[46] = 4.21, p < 0.001).

CONCLUSIONS

During accurate NoGo but impaired Go trial performance, children with BD showed increased right DLPFC activation versus controls, suggesting increased recruitment of executive control regions for accurate response inhibition. Studies relating these results to mood regulation in pediatric BD are warranted.

Neurocognitive impairment in unaffected siblings of youth with bipolar disorder

BACKGROUND

There is growing evidence for the familiality of pediatric bipolar disorder (BPD) and its association with impairments on measures of processing speed, verbal learning and 'executive' functions. The current study investigated whether these neurocognitive impairments index the familial risk underlying the diagnosis.

METHOD

Subjects were 170 youth with BPD (mean age 12.3 years), their 118 non-mood-disordered siblings and 79 non-mood-disordered controls. Groups were compared on a battery of neuropsychological tests from the Wechsler Intelligence Scales, the Stroop Color Word Test, the Wisconsin Card Sorting Test (WCST), the Rey-Osterrieth Complex Figure (ROCF), an auditory working memory Continuous Performance Test (CPT) and the California Verbal Learning Test-Children's Version (CVLT-C). Measures were factor analyzed for data reduction purposes. All analyses controlled for age, sex and attention-deficit/hyperactivity disorder (ADHD).

RESULTS

Principal components analyses with a promax rotation yielded three factors reflecting: (1) processing speed/verbal learning, (2) working memory/interference control and (3) abstract problem solving. The CPT working memory measure with interference filtering demands (WM INT) was only administered to subjects aged > or =12 years and was therefore analyzed separately. BPD youth showed impairments versus controls and unaffected relatives on all three factors and on the WM INT. Unaffected relatives exhibited impairments versus controls on the abstract problem-solving factor and the WM INT. They also showed a statistical trend (p=0.07) towards worse performance on the working memory/interference control factor.

CONCLUSIONS

Neurocognitive impairments in executive functions may reflect the familial neurobiological risk mechanisms underlying pediatric BPD and may have utility as endophenotypes in molecular genetic studies of the condition.

Bipolar patients in community mental health centers and specialized units. Could they be pooled?

INTRODUCTION

Bipolar patients recruited for studies are usually picked from Bipolar Disorder Units, which only contain a fraction of the total population of patients with bipolar disorder. The purpose of this study was to determine whether the course of the illness is comparable in patients from a Community Mental Health Center (CMHC) and those from a Bipolar Disorder Unit (BDU).

METHODS

This study was carried out at the La Fe Teaching Hospital BDU and two CMCH. Data were collected from the patients' clinical records and were completed by a face-toface interview. When the latter was not possible, a telephone interview was carried out. Demographic, clinical and course-of-illness variables were gathered.

RESULTS

There were no differences in demographic characteristics between the two patient groups. Differences were found in clinical data: BDU patients were younger at illness onset (p<0.005), were admitted more frequently (p<0.05), and stayed longer in the hospital (p<0.005).

CONCLUSIONS

Bipolar patients treated at a CMHC show clear differences compared with those from a BDU. Consequently, care should be exercised when generalizing the clinical course of bipolar patients using BDU samples. These patients are not representative of the total bipolar patient population, as their clinical course is more complicated.

Increased intrasubject variability in response time in youths with bipolar disorder and at-risk family members

OBJECTIVE

Deficits in sustained attention may represent an endophenotype for bipolar disorder (BD). One heritable measure of sustained attention is intrasubject variability in response time (ISV-RT). We tested the hypothesis that, compared with controls, both youths with BD and those at familial risk for the disorder would have increased ISV-RT.

METHOD

Subjects were 28 patients with BD, 26 unaffected youths with a first-degree relative with BD, and 24 control youths without an affected relative, all aged 7 to 17 years. Subjects completed the Flanker Continuous Performance Test.

RESULTS

Bipolar disorder and at-risk youths had increased ISV-RT, compared with the controls. Differences were independent of comorbid psychopathology in youths with BD and present in psychiatrically healthy at-risk youths.

CONCLUSIONS

Increased ISV-RT may be a risk marker for BD. Further research is needed to investigate the neural and genetic underpinnings of this deficit, as well as the specificity of the finding to BD.

The adverse consequences of sleep disturbance in pediatric bipolar disorder: implications for intervention

Bipolar disorder (BPD) is a severe and chronic disorder, ranked among the top 10 leading causes of disability worldwide. Bipolar spectrum disorders with onset in childhood and adolescence have a particularly severe course, including more suicide attempts and greater comorbidity. The evidence accrued to date indicates that sleep disturbances are common among youth with BPD. Moreover, sleep problems may be an early marker for BPD, a distinguishing feature of BPD, and a contributor to relapse. The evidence reviewed highlights that sleep problems are associated with a range of serious adverse consequences, including difficulty in regulating affect in the daytime and difficulties with cognitive functions, such as memory, learning, attention, and concentration. Evidence reviewed also points to sleep disturbance as one possible contributor to weight gain, comorbid substance use, and impulsivity. The implications for intervention are explored, and a multicomponent sleep intervention for youth with BPD is outlined.

Diffusion tensor imaging study of white matter fiber tracts in pediatric bipolar disorder and attention-deficit/hyperactivity disorder

BACKGROUND

To investigate microstructure of white matter fiber tracts in pediatric bipolar disorder (PBD) and attention-deficit/hyperactivity disorder (ADHD).

METHODS

A diffusion tensor imaging (DTI) study was conducted at 3 Tesla on age- and IQ-matched children and adolescents with PBD (n = 13), ADHD (n = 13), and healthy control subjects (HC) (n = 15). Three DTI parameters, fractional anisotropy (FA), apparent diffusion coefficient (ADC), and regional fiber coherence index (r-FCI), were examined in eight fiber tracts: anterior corona radiata (ACR), anterior limb of the internal capsule (ALIC), superior region of the internal capsule (SRI), posterior limb of the internal capsule (PLIC), superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), cingulum (CG), and splenium (SP).

RESULTS

Significantly lower FA was observed in ACR in both PBD and ADHD relative to HC. In addition, FA and r-FCI values were significantly lower in ADHD relative to PBD and HC in both the ALIC and the SRI. Further, ADC was significantly greater in ADHD relative to both the PBD and HC in ACR, ALIC, PLIC, SRI, CG, ILF, and SLF.

CONCLUSIONS

Decreased FA in ACR implies an impaired fiber density or reduced myelination in both PBD and ADHD in this prefrontal tract. These abnormalities, together with the reduced fiber coherence, extended to corticobulbar tracts in ADHD. Increased ADC across multiple white matter tracts in ADHD indicates extensive cellular abnormalities with less diffusion restriction in ADHD relative to PBD.

Neurocognitive function in pediatric bipolar disorder: 3-year follow-up shows cognitive development lagging behind healthy youths

OBJECTIVE

Longitudinal follow-up of neurocognitive functioning in people with pediatric bipolar disorder (PBD) was conducted to characterize the developmental trajectory of cognitive disabilities in this disorder.

METHOD

Patients with PBD (n = 26) and controls (HC; n = 17; mean age 11.66 +/- 2.70 years) completed cognitive testing at baseline and then again at a 3-year follow-up. Groups were matched at baseline on age, sex, race, parental socioeconomic status, general intelligence, and single-word reading ability. The PBD group received treatment guided by a standardized medication algorithm during the 3-year period. A battery of neuropsychological tests was administered to assess attention, executive function, working memory, verbal memory, visual memory, and visuospatial perception at baseline and follow-up.

RESULTS

At baseline and follow-up, the patients showed deficits in all of the examined domains. At 3-year follow-up, developmental progress in executive functions and verbal memory was significantly less in the patients with PBD than in the HC. Improvement on attention, working memory, visual memory, and visuospatial perception tasks in the patients with PBD was comparable to that of the HC, but the patients with PBD remained impaired in all domains relative to the HC.

CONCLUSIONS

The developmental delay in some neurocognitive functioning in PBD suggests that the illness disrupts cognitive development with potential lifelong implications for reduced functional ability. Treating bipolar symptoms does not seem to prevent the lag in cognitive development. This dysmaturation may be a direct effect of the illness on brain function, or it may represent indirect consequences of psychopathology or medications on cognitive development.

Long-term safety of divalproex sodium extended-release in children and adolescents with bipolar I disorder

OBJECTIVE

The objective of this open-label study was to assess the safety of divalproex sodium extended-release in the treatment of children and adolescents with acute mania associated with bipolar I disorder.

METHODS

This was a 6-month, Phase 3, open-label study in healthy subjects aged 9-17 years with a current Diagnostic and Statistical Manual of Mental Disorders, 4(th) edition, Text Revision (DSM-IV-TR) diagnosis of bipolar I disorder manic or mixed episode. Divalproex sodium extended-release (DVPX-ER) was initiated at 15 mg/kg per day on day 1 (not to exceed 750 mg/day) with increases allowed to a maximum of 35 mg/kg per day. Study visits were conducted on day 1 and at months 1, 2, 3, and 6. Assessments included standard safety evaluations and appropriate rating scales for clinical effect.

RESULTS

A total of 226 subjects were enrolled; 109 subjects completed the study. The most common adverse events were weight gain (16%), nausea (9%), and increased appetite (8%). Nonsymptomatic elevations of mean ammonia levels in plasma were observed. The mean Young Mania Rating Scale (YMRS) decreased 12.4 from baseline to final visit; small improvements were seen in behavior and caregiver stress ratings.

CONCLUSIONS

DVPX-ER was generally well tolerated in children and adolescents with acute mania, with a side-effect profile similar to that observed in adults.

A quantitative and qualitative review of neurocognitive performance in pediatric bipolar disorder

Bipolar disorder (BD) is an increasingly prevalent diagnosis in youth. As a result, there has been a corresponding increase in interest about neuropsychological and cognitive profiles in children and adolescents diagnosed with BD. Meta-analysis of the existing literature comparing individuals with BD to healthy controls indicated that the largest differences are observed for measures of verbal memory (d = 0.77). Moderate differences were found in the areas of attention (d = 0.62), executive functioning (d = 0.62), working memory (d = 0.60), visual memory (d = 0.51), visual perceptual skills (d = 0.48), and verbal fluency (d = 0.45). Small differences were found for measures of reading (d = 0.40), motor speed (d = 0.33), and full-scale intelligence quotient (IQ) (d = 0.32). Often, few studies have provided relevant information for a particular neurocognitive domain. Despite this, several domains displayed heterogeneity of effect sizes across studies. Methodological factors explained the variance in effect sizes to different extents depending upon the cognitive domain. The changing influence of method artifacts is likely due to variable coverage of cognitive domains across studies and the use of different measures across studies. Findings are consistent with previous meta-analyses of the adult BD neurocognitive literature, suggesting that many of the deficits observed in adults are present earlier in the course of the illness. Study reporting guidelines are offered that may help clarify the impact of illness definitions, mood state, medication status, and other methodological variables on neurocognition in pediatric BD.

A functional MRI study of Theory of Mind in euthymic bipolar disorder patients

OBJECTIVES

To determine the neural responses invoked in Theory of Mind (ToM) in euthymic bipolar patients as compared with healthy subjects.

METHODS

This study examined 20 euthymic bipolar patients (11 males and 9 females) and 20 suitably matched healthy subjects using functional magnetic resonance imaging (fMRI) while subjects were engaged in a ToM task. Within-scanner eye movements were monitored to ensure task engagement. The activation paradigm involved observing ToM and random-motion animated sequences in a block design. Both within group (ToM versus random motion) and random effects between group analyses were performed on fMRI data using the BrainVoyager software package. Demographic and clinical data, along with subject ratings of fMRI stimuli, were collated and analysed.

RESULTS

Patients were compromised in their ability to appropriately rate the ToM stimuli and assess them for intention as compared to healthy subjects. This was reflected in the fact that patients had few within-group significant activations in response to ToM animated sequences, namely, the left anterior cingulate, and precuneus and cuneus bilaterally. In contrast, robust activations in response to ToM animated sequences in healthy subjects were widespread and involved regions recognized for mental state reasoning, in particular the insula, inferior frontal, supramarginal and angular gyri, and temporal cortex. The between-group random effects analysis exclusively favoured the healthy subjects, with many activations occurring in regions overlapping with those found in the within-group analyses.

CONCLUSIONS

The findings of this novel neuroimaging study suggest that in a social context, euthymic bipolar patients, though seemingly well and capable of engaging aspects of ToM, are perhaps constrained in their ability to mentalize fully, and furthermore cannot reliably adopt an alternate cognitive perspective when appropriate. Impairment of this capacity, though subtle, may in effect compromise their ability to understand the emotions and intentions of others, and also may limit appreciation of their own illness and symptoms. Such a deficit in bipolar disorder perhaps impacts upon interpersonal relationships and adversely affects social cognition and clinical functioning. The potential implications of this putative mentalizing compromise in euthymic patients with bipolar disorder are substantial, both for the individual and for understanding the neural substrate of the illness, and therefore warrant further investigation.

Neurocognitive allied phenotypes for schizophrenia and bipolar disorder

Psychiatric disorders are genetically complex and represent the end product of multiple biological and social factors. Links between genes and disorder-related abnormalities can be effectively captured via assessment of phenotypes that are both associated with genetic effects and potentially contributory to behavioral abnormalities. Identifying intermediate or allied phenotypes as a strategy for clarifying genetic contributions to disorders has been successful in other areas of medicine and is a promising strategy for identifying susceptibility genes in complex psychiatric disorders. There is growing evidence that schizophrenia and bipolar disorder, rather than being wholly distinct disorders, share genetic risk at several loci. Further, there is growing evidence of similarity in the pattern of cognitive and neurobiological deficits in these groups, which may be the result of the effects of these common genetic factors. This review was undertaken to identify patterns of performance on neurocognitive and affective tasks across probands with schizophrenia and bipolar disorder as well as unaffected family members, which warrant further investigation as potential intermediate trait markers. Available evidence indicates that measures of attention regulation, working memory, episodic memory, and emotion processing offer potential for identifying shared and illness-specific allied neurocognitive phenotypes for schizophrenia and bipolar disorder. However, very few studies have evaluated neurocognitive dimensions in bipolar probands or their unaffected relatives, and much work in this area is needed.

Avaliação neuropsicológica dos transtornos psicológicos na infância: um estudo de revisão

Este artigo apresenta uma revisão da literatura sobre a avaliação neuropsicológica dos déficits cognitivos associados aos transtornos psicológicos na infância e adolescência, com base em pesquisas publicadas no período de 2000 a 2006. Foi realizado um levantamento abrangendo publicações nacionais e internacionais indexadas nas bases de dados Medline, SciELo e PsycInfo. Os resultados indicaram um aumento da produção científica na área da avaliação neuropsicológica do transtorno de déficit de atenção e hiperatividade, autismo, transtornos de humor e transtorno de conduta. Observou-se a presença de poucos estudos nacionais, indicando a necessidade de pesquisas na área de avaliação neuropsicológica no Brasil.

Theory of mind and social inference in children and adolescents with bipolar disorder

BACKGROUND

Deficits in theory of mind (ToM), or the ability to infer what another person is thinking or feeling, have been reported in manic and euthymic adults with bipolar disorder. To date, there have been no investigations of ToM in pediatric bipolar disorder (PBD). The aim of the current study was to investigate this ability in PBD patients and healthy controls.

METHOD

PBD patients (n=26) and intellectually and demographically similar healthy comparison subjects (n=20) were administered two ToM tasks. In the Affective Story Task, subjects were read positive-, negative- and neutral-valenced stories, and were assessed on their ability to recognize that a misleading series of events could lead one character to develop a false belief about another character. On the Hinting Task, subjects were required to infer the real intentions behind subtle hints.

RESULTS

The PBD group performed significantly more poorly than controls on the Hinting Task and the positive and negative conditions of the Affective Story Task. In the PBD group only, younger age, earlier illness onset and manic symptoms were associated with poorer ToM performance.

CONCLUSIONS

Consistent with past findings in adult bipolar disorder (BD), PBD youth performed more poorly than controls on ToM tasks. Data suggest that ToM ability may be more impaired in affectively charged contexts. Additionally, an earlier onset of illness among PBD youth may interfere with the development of social-cognitive skills. ToM disturbances may be a useful treatment target in PBD, with the aim of facilitating more accurate assessment of social cues and better interpersonal functioning.

Inhibition and attention in adolescents with nonmanic mood disorders and a high risk for developing mania

This study examines psychomotor inhibition, sustained attention, and inhibitory attentional control in adolescents (ages 12-18 years) with a nonmanic mood disorder and with a first-degree relative with bipolar I disorder (MD, N = 20) and demographically matched healthy children of parents without any psychiatric disorder (HC, N = 13). MD participants showed abnormal performance in stop signal reaction time and latency (d = 1.28 and 1.64, respectively), sustained attention response bias (d = 0.75), and color naming speed (d = 0.88). The results indicate that MD participants exhibit psychomotor disinhibition, marginal cognitive slowing and cautious response biases, but no formal deficits in sustained or selective attention.

Biologic basis of bipolar disorder in children and adolescents

Bipolar disorder is a serious and difficult-to-treat condition in any age group. In childhood and adolescence, diagnosis and treatment present specific challenges, as the disorder often manifests in atypical presentations, such as marked irritability and frequent alterations of mood states not typically seen in adults. The lack of double-blind, placebo-controlled studies in pediatric populations also leads to many difficult pharmacologic challenges. In this paper, we review available studies in neuroanatomy, neurochemistry, neurocognitive functioning, and genetics to further explore the underlying neurobiologic mechanisms of child and adolescent bipolar disorder. Future investigation should elicit distinct mechanisms for diagnosing and treating bipolar disorder from a neurobiologic perspective.

Diagnosis and classification of pediatric bipolar disorder

BACKGROUND

Many children and adolescents with apparent bipolar disorder cannot be meaningfully diagnosed using the DSM-IV. The variety of pediatric bipolar phenotypes observed in clinical practice remains unclarified.

METHOD

130 consecutively evaluated bipolar children and adolescents were assessed using semistructured clinical interviews and operational criteria that abandoned adherence to the DSM-IV cardinal symptom, duration of symptom persistence, and episodicity requirements.

RESULTS

97.6% of the total sample manifested either all three, or two of the three symptoms elation, grandiosity, and racing thoughts, when manic. 96.9% of the total sample exhibited five or more of the eight DSM-IV criterion symptoms when manic. 52.3% of the subjects manifested ultradian cycling; 22.3% manifested chronic mania or chronic simultaneous manic mixed conditions. Only 21.5% could be classified within the Leibenluft et al. [Leibenluft, E., Charney, D.S., Towbin, K.E., Bhangoo, R.K., Pine, D.S., 2003. Defining clinical phenotypes of juvenile mania. Am. J. Psychiatry 160, 430-437.] system. Problematic distractibility-inattention was present in 89.9% and recurrent rage attacks in 48.5% of the total sample. Older subjects exhibited significantly more depressive symptoms, and nonsignificantly greater prevalences of major depression, severe depression, and ultradian cycling than did younger subjects. The number of depressive symptoms was significantly correlated with ultradian cycling.

LIMITATIONS

This study relied upon retrospective as well as current reports of symptoms. The study results cannot be generalized to community samples.

CONCLUSIONS

We propose two testable hypotheses: (1) that the recurrent, or chronic, simultaneous presence of any two of the symptoms elation, grandiosity, and racing thoughts and a total of five DSM-IV manic symptoms (without specific cardinal symptom, duration, or episodicity requirements) will identify nearly all clinic-referred bipolar children and adolescents; and (2) that a comprehensive classification of pediatric bipolar phenotypes based upon pattern of manic symptom episodicity or chronicity and degree of depression will identify subtypes of pediatric bipolar disorder that have greater correspondence with treatment response than do those of the DSM-IV classification. Problematic distractibility-inattention and explosive irritability-rage are highly prevalent; their presences should be specified when indicated.

Neural activation during encoding of emotional faces in pediatric bipolar disorder

OBJECTIVE

Neurobiological understanding of bipolar disorder (BD) is limited by a paucity of functional magnetic resonance imaging (fMRI) research examining correlates of psychological processes. To begin to address these limitations, the current study tests the hypothesis that pediatric BD (PBD) subjects exhibit altered neural activation during encoding of emotional faces compared to typically developing controls.

METHODS

Pediatric BD subjects (n=23; mean age=14.2+/-3.1 years) and controls (n=22; mean age=14.7+/-2.3 years) were matched on age, gender, and IQ. In this event-related fMRI study, subjects were scanned while viewing emotional faces and given a surprise recognition memory test 30 min postscan. Our main outcome measure was between-group differences in neural activation during successful versus unsuccessful face encoding.

RESULTS

Pediatric BD youth exhibited reduced memory for emotional faces, relative to healthy comparisons, particularly on fearful faces. Event-related fMRI analyses controlling for this behavioral difference showed that PBD subjects, compared to controls, had increased neural activation in the striatum and anterior cingulate cortex when successfully encoding happy faces and in the orbitofrontal cortex when successfully encoding angry faces. There were no between-group differences in neural activation during fearful face encoding.

CONCLUSIONS

Our results extend what is known about memory and face emotion processing impairments in PBD subjects by showing increased fronto-striatal activation during encoding of emotional faces. Further work is required to determine the impact of mood state, medication, and comorbid illnesses on these findings.

Do cognitive deficits in juvenile bipolar disorder persist into adulthood?

This article reviews neuropsychological research in adults with bipolar disorder and compares the findings with emergent data on neuropsychological function in juvenile bipolar disorder. Despite a recent surge of interest in childhood onset bipolar disorder, there remains a scarcity of neuropsychological literature investigating this population. From the study of adult bipolar disorder a substantial body of literature points to the existence of trait deficits in verbal and executive function that are detectable even during euthymia. In the nascent literature on neuropsychology in early onset bipolar, there is growing evidence to suggest that some of the deficits apparent in adults are also discernible in adolescents. Precise knowledge about when, how, and why these deficits appear requires future research of prodromal changes in neurocognition in childhood and adolescent bipolar disorder.

Attention-deficit/hyperactivity disorder: a neuropsychological perspective towards DSM-V

Neuropsychological methods and techniques have much to offer in the evaluation of the individual suspected as having Attention-Deficit/Hyperactivity Disorder (ADHD). After a review of the historical evolution of the ADHD concept, incidence and prevalence, and DSM-IV criteria for diagnosis, especially as regards omission related to gender differences, and other associated cultural, familial, socioenvironmental, and subject influences, this paper describes a number of dilemmas and obstacles encountered in clinical practice. Included are the confounds associated with the wide range of possible comorbidities, the insufficiency of current DSM-IV criteria, the emergence of subtype differentiation and its impact on diagnosis and treatment. The complex relationship between neuropsychological constructs and ADHD, and obstacles to valid assessment are also addressed. The complexities associated with a thorough ADHD evaluation are viewed within an impressive and expansive existing scientific framework and recommendations are made for future directions.

Affective neural circuitry during facial emotion processing in pediatric bipolar disorder

BACKGROUND

Facial emotions are central to human interaction. Identifying pathophysiology in affect processing circuitry that supports the ability to assess facial emotions might facilitate understanding of affect regulation in pediatric bipolar disorder.

METHODS

Ten euthymic, unmedicated pediatric bipolar patients and 10 healthy control subjects matched for age, gender, race, socioeconomic status, and IQ were scanned with functional magnetic resonance imaging. Angry, happy, and neutral faces were presented in 30-sec blocks, with a 20-sec rest period between blocks. Subjects were asked to press a button when each face appeared, to ensure that attention was maintained on-task.

RESULTS

In bipolar patients, in response to both angry and happy faces relative to neutral faces, we observed reduced activation of right rostral ventrolateral prefrontal cortex together with increased activity in right pregenual anterior cingulate, amygdala, and paralimbic cortex. Bipolar patients also showed reduced activation of visual areas in occipital cortex together with greater activation in higher-order visual perceptual areas, including superior temporal sulcus and fusiform gyrus with angry faces and posterior parietal cortex with happy faces.

CONCLUSIONS

Findings document a disturbance in affective neurocircuitry in pediatric bipolar disorder. Reduced activation in ventrolateral prefrontal cortex might reflect diminished top-down control that leads to the observed exaggerated activation in amygdala and paralimbic areas. Changes in occipital areas might represent an effort to gate sensory input when affective responses to the faces could not be successfully modulated. Disturbances in affect processing circuitry could contribute to emotional dysregulation and social cognitive difficulties in bipolar youth.

Evidence for disruption in prefrontal cortical functions in juvenile bipolar disorder

OBJECTIVES

Systematic parsing of executive function processes is critical for the development of more specific models of neurobiological processes mediating disturbed cognition in youth with bipolar disorder (BPD).

METHODS

A sample of 33 children and adolescents with bipolar I disorder (BPD I) (mean age 12.1 +/- 3.0 years, 39% female) and 44 demographically matched healthy participants (mean age 12.9 +/- 2.8 years, 50% female) completed a neurocognitive battery including measures aimed at detection of disruption in prefrontal cortical circuitry (i.e., working memory, set shifting, and rule attainment).

RESULTS

Compared to healthy controls, BPD I children exhibited significant deficits in spatial working memory, visual sequencing and scanning, verbal fluency and abstract problem solving, particularly when a memory component was involved. In our spatial delayed response task, memory set size was parametrically varied; the performance pattern in BPD I children suggested deficits in short-term memory encoding and/or storage, rather than capacity limitations in spatial working memory. Earlier age at onset of illness and antipsychotic medication usage were associated with poorer performance on speeded information-processing tasks; however, severity of mood symptomatology and comorbidity with disruptive behavior disorders were not associated with task performance.

CONCLUSIONS

These results suggest impairment in measures of prefrontal cortical function in juvenile BPD I that are similar to those seen in the adult form of the illness, and implicate both the ventral and dorsolateral prefrontal cortex as loci of pathology in juvenile BPD. As these deficits were not associated with clinical state or comorbidity with other disorders, they may reflect trait-related impairments, a hypothesis that will be pursued further in longitudinal studies.

Manic symptoms and behavioral dysregulation in youth with velocardiofacial syndrome (22q11.2 deletion syndrome)

Mania and bipolar disorder have been reported in adolescents and adults with velocardiofacial syndrome (VCFS; also known as 22q11.2 deletion syndrome). Children with VCFS have a high prevalence of attention-deficit/hyperactivity disorder (ADHD), which may constitute a risk factor for the eventual development of bipolar disorder in this population. Therefore, we sought to determine whether children with VCFS exhibit more manic symptoms than community controls that also may have learning disorders and ADHD. The study population consisted of 86 children with VCFS and 36 community controls from ages 9 to 15 years, using measures of Young Mania Rating Scale-Parent Version, Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL), Child Behavior Checklist (CBCL), and Wechsler Intelligence Scale for Children-3rd edition (WISC-III). The results indicate that manic symptoms were not more prevalent in VCFS than in a community sample of children with learning disorders and ADHD. However, after accounting for symptoms of depression and ADHD, we found that manic symptoms in VCFS predicted uniquely to scores on four Child Behavior Checklist (CBCL) subscales, including anxiety, somatization, thought, and conduct problems. In contrast, manic symptoms in controls predicted uniquely to conduct problems only. Accordingly, our findings of severe behavioral impairment in youth with VCFS and manic symptoms suggest that these children may warrant more intensive monitoring and treatment relative to youth with VCFS and ADHD only.

Information processing profiles of internalizing and externalizing behavior problems: evidence from a population-based sample of preadolescents

BACKGROUND

The present study explores the relationships between several information processing capacities and internalizing and externalizing behavior problems in a general population sample of 10- to 12-year olds (N = 2,037 51% girls).

METHODS

Parent-reported behavior problems as assessed by the Child Behavior Checklist were used to form four groups of children with 1) neither internalizing nor externalizing problems (n = 1,470), 2) only internalizing problems (n = 237), 3) only externalizing problems (n = 182), and 4) both internalizing and externalizing problems (n = 148). These groups were compared on measures of speed and accuracy from the Amsterdam Neuropsychological Tasks program reflecting the efficiency of several input-, central cognitive-, and output-related information processing capacities.

RESULTS

Children with both internalizing and externalizing problems demonstrated the least efficient performance, followed by children with only externalizing problems, whereas children with only internalizing problems did not differ from children without problems. More specifically, response variability and the ability to maintain and quickly compare information in working memory were found to be related to the severity of problem behavior. The ability to inhibit prepotent responses was related to the type of problem behavior, discriminating between the children with only internalizing problems and only externalizing problems. However, this latter capacity no longer differentiated when controlling for IQ. No differences were found between boys and girls.

CONCLUSIONS

The results suggest that, in general, cognitive processing deficits are more strongly related to the degree than to the type of maladaptive behavior. Furthermore, response variability and working memory may serve as potential markers for identifying high-risk children and response inhibition as an indicator of the type of maladaptive behavior.

Neuropsychological functioning in adolescent children of mothers with a history of bipolar or major depressive disorders

BACKGROUND

Growing evidence demonstrates an association of neuropsychological deficits with mood disorders, but it is not yet clear whether these deficits are risk factors or are concomitant with the symptoms. This study examines the neuropsychological functioning of a group of adolescent offspring who are at risk for a mood disorder by virtue of being raised by mothers who have been diagnosed with major depressive disorder (MDD) or bipolar disorder (BPD).

METHODS

Adolescent offspring of mothers with BPD (n = 43) or MDD (n = 72) and of psychiatrically well parents (n = 50) completed a battery of neuropsychological tests to assess executive functioning, memory, and attention.

RESULTS

Children of mothers with BPD showed deficits in executive functioning and selective deficits in spatial memory and attention, in comparison with children of well mothers. Deficits were not found for children of MDD mothers.

CONCLUSIONS

Knowledge of these neurocognitive processes could aid ultimately in determining whether neurocognitive deficits precede BPD, whether unique profiles are associated with various types of mood disorders, and who may benefit from interventions.

Impact of ADHD on the neurocognitive functioning of adolescents with bipolar disorder

BACKGROUND

Pediatric Bipolar Disorder (BD) has been associated with a number of neurocognitive deficits not dissimilar to ADHD. This study compared neuropsychological profiles of 4 groups of adolescents (14-17 years): 41 Normal Controls (NC), 30 ADHD, 12 BD and 12 combined (BD+ADHD).

METHODS

Participants were identified according to a standardized protocol (WASHU-KSADS mood section, K-SADS-PL and Conners Scales) and completed tests of processing speed, memory, executive functioning, set shifting, and inhibition. ADHD adolescents on stimulant medication did not take it on the day.

RESULTS

After controlling for covariates, the ADHD-only and combined groups were most impaired, including processing and naming speed, working memory, and response inhibition. The ADHD-only group showed specific impairment in naming objects, numbers and letters than the NC and showed greater deficits than the BD-only group on tests of naming speed. The combined group showed greatest deficits in verbal memory and inhibitory control. Other than working memory, there were no differences between the BD-only and NC groups. Removal of BD-NOS did not impact on the results.

CONCLUSIONS

This study failed to find broad neurocognitive deficits in BD-only adolescents. Only those with comorbid ADHD showed cognitive deficits, highlighting the impact ADHD may have on neurocognitive functioning of BD.

Impact of neurocognitive function on academic difficulties in pediatric bipolar disorder: A clinical translation

BACKGROUND

Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD.

METHODS

A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning.

RESULTS

Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone.

CONCLUSIONS

In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD.

Sustained attention deficits in manic and euthymic patients with bipolar disorder

Sustained attention deficits are proposed to be both state and trait indicators of bipolar disorder. The nature of these deficits and their association with medication and symptoms is not clear yet. The aim of this study was to investigate the impairments in various components of sustained attention task in euthymic and manic patients and was to investigate the relationship between the deficits in the manic state and medication effects. The performances of 37 manic patients, 34 euthymic patients with bipolar disorder and 34 control subjects on eight scores from Conners' CPT II, reflecting three different dimensions of sustained attention were compared. Similar to some recent findings, euthymic patients had decreased target sensitivity (omission errors) and response time inconsistency. The increased false responding (commission errors), perseveration and vigilance deficits were prominent in the manic patients. These state dependent impairments could not be explained by the impact of medication. In contrast, the exacerbation of seemingly trait-related impairments in the manic state can be at least partly explained by the impact of pharmacological therapy.

Clinical and empirical applications of the Rey–Osterrieth Complex Figure Test

The Rey-Osterrieth Complex Figure Test (ROCF), which was developed by Rey in 1941 and standardized by Osterrieth in 1944, is a widely used neuropsychological test for the evaluation of visuospatial constructional ability and visual memory. Recently, the ROCF has been a useful tool for measuring executive function that is mediated by the prefrontal lobe. The ROCF consists of three test conditions: Copy, Immediate Recall and Delayed Recall. At the first step, subjects are given the ROCF stimulus card, and then asked to draw the same figure. Subsequently, they are instructed to draw what they remembered. Then, after a delay of 30 min, they are required to draw the same figure once again. The anticipated results vary according to the scoring system used, but commonly include scores related to location, accuracy and organization. Each condition of the ROCF takes 10 min to complete and the overall time of completion is about 30 min.

[Bipolar disorder in childhood and adolescence]

Many advances in the knowledge of childhood- and adolescent-onset bipolar disorder have been seen over the last 15 years. Current efforts focus on investigating clinical features, developing more instruments for early diagnosis and improving treatment research. The present study aims to present the main clinical characteristic of the disorder in children and adolescents, as well as the nomenclature, description of clinical phenotypes and the most common cycling pattern in youths. A discussion of comorbidity, differential diagnosis and advances in psychopharmacological treatment will also be presented.