Neuropsychological performance in pediatric bipolar disorder

The Simultaneous Assessment of Time and Motion Response during Dual Tasks

Measurement of reaction time in clinical settings is generally employed to assess cognitive abilities by having a subject perform standard simple tests. In this study, a new method of measuring response time (RT) was developed using a system composed of LEDs that emit light stimuli and are equipped with proximity sensors. The RT is measured as the time taken by the subject to turn off the LED target by moving the hand towards the sensor. Through an optoelectronic passive marker system, the associated motion response is assessed. Two tasks of 10 stimuli each were defined: simple reaction time and recognition reaction time tasks. To validate the method implemented to measure RTs, the reproducibility and repeatability of the measurements were estimated, and, to test the method's applicability, a pilot study was conducted on 10 healthy subjects (6 females and 4 males, age = 25 ± 2 years), reporting, as expected, that the response time was affected by the task's difficulty. Unlike commonly used tests, the developed method has proven to be adequate for the simultaneous evaluation of the response in terms of time and motion. Furthermore, thanks to the playful nature of the tests, this method could also be used for clinical and pediatric applications to measure the impact of motor and cognitive impairments on RT.

Cognitive Flexibility and Impulsivity Deficits in Suicidal Adolescents

Although neurocognitive deficits have been documented in adolescents with suicidal ideation (SI) and suicide attempts (SA), it is unclear whether certain impairments differentiate these groups, potentially suggesting heightened risk for SA. Focus on specific facets of impulsivity and cognitive control may indicate distinctions between adolescents with SA vs. SI. The current study examined dimensions of impulsivity and cognitive control in 141 adolescents with SA (n = 41) vs. SI without SA (n = 49) vs. typically-developing controls (TDCs; n = 51). Adolescents completed cross-sectional neurocognitive tasks via the Cambridge Neuropsychological Testing Automated Battery, in addition to demographic and clinical measures. Analyses involved ANOVAs and ANCOVAs. Results indicated that adolescents with SA demonstrated less set shifting/cognitive flexibility (reduced ability to adapt to/disengage from stimuli) and greater impulsive decision making (reduced ability to collect/evaluate information before making decisions) compared to TDCs. In addition, both TDCs and adolescents with SA had greater response inhibition (increased ability to stop motor responses that have begun/become prepotent) than those with SI. Similar results were found when analyzing female adolescents separately. There were no significant differences for male adolescents, potentially due to the small subsample (n = 40). There were no significant findings for spatial planning/problem solving or visuospatial working memory. Findings suggest: 1) less set shifting/cognitive flexibility and greater impulsive decision making for adolescents with SA vs. TDCs; and 2) greater response inhibition for TDCs and adolescents with SA vs. SI. Such information may be useful for improving risk assessments (adding neurocognitive tasks) and targeted treatments (incorporating cognitive remediation) for this impaired population.

Lurasidone versus Quetiapine for Cognitive Impairments in Young Patients with Bipolar Depression: A Randomized, Controlled Study

The clinical efficacy of lurasidone and quetiapine, two commonly prescribed atypical antipsychotics for bipolar depression, has been inadequately studied in young patients. In this randomized and controlled study, we aimed to compare the effects of these two drugs on cognitive function, emotional status, and metabolic profiles in children and adolescents with bipolar depression. We recruited young participants (aged 10-17 years old) with a DSM-5 diagnosis of bipolar disorder during a depressive episode, who were then randomly assigned to two groups and treated with flexible doses of lurasidone (60 to 120 mg/day) or quetiapine (300 to 600 mg/day) for consecutive 8 weeks, respectively. All the participants were clinically evaluated on cognitive function using the THINC-it instrument at baseline and week 8, and emotional status was assessed at baseline and the end of week 2, 4, and 8. Additionally, the changes in weight and serum metabolic profiles (triglyceride, cholesterol, and fasting blood glucose) during the trial were also analyzed. In results, a total of 71 patients were randomly assigned to the lurasidone group (n = 35) or the quetiapine group (n = 36), of which 31 patients completed the whole treatment course. After an 8-week follow-up, participants in the lurasidone group showed better performance in the Symbol Check Reaction and Accuracy Tests, when compared to those in the quetiapine group. No inter-group difference was observed in the depression scores, response rate, or remission rate throughout the trial. In addition, there was no significant difference in serum metabolic profiles between the lurasidone group and the quetiapine group, including triglyceride level, cholesterol level, and fasting blood glucose level. However, the quetiapine group presented a more apparent change in body weight than the lurasidone group. In conclusion, the present study provided preliminary evidence that quetiapine and lurasidone had an equivalent anti-depressive effect, and lurasidone appeared to be superior to quetiapine in improving the cognitive function of young patients with bipolar depression.

Relationship between cognitive flexibility and subsequent course of mood symptoms and suicidal ideation in young adults with childhood-onset bipolar disorder

Neurocognitive deficits, such as cognitive flexibility impairments, are common in bipolar disorder (BD) and predict poor academic, occupational, and functional outcomes. However, the association between neurocognition and illness trajectory is not well understood, especially across developmental transitions. This study examined cognitive flexibility and subsequent mood symptom and suicidal ideation (SI) course in young adults with childhood-onset BD-I (with distinct mood episodes) vs. BD-not otherwise specified (BD-NOS) vs. typically-developing controls (TDCs). Sample included 93 young adults (ages 18-30) with prospectively verified childhood-onset DSM-IV BD-I (n = 34) or BD-NOS (n = 15) and TDCs (n = 44). Participants completed cross-sectional neuropsychological tasks and clinical measures. Then participants with BD completed longitudinal assessments of mood symptoms and SI at 6-month intervals (M = 39.18 ± 16.57 months of follow-up data). Analyses included ANOVAs, independent-samples t tests, chi-square analyses, and multiple linear regressions. Participants with BD-I had significant deficits in cognitive flexibility and executive functioning vs. BD-NOS and TDCs, and impaired spatial working memory vs. TDCs only. Two significant BD subtype-by-cognitive flexibility interactions revealed that cognitive flexibility deficits were associated with subsequent percentage of time depressed and with SI in BD-I but not BD-NOS, regardless of other neurocognitive factors (full-scale IQ, executive functioning, spatial working memory) and clinical factors (current and prior mood and SI symptoms, age of BD onset, global functioning, psychiatric medications, comorbidity). Thus, cognitive flexibility may be an important etiological brain/behavior mechanism, prognostic indicator, and intervention target for childhood-onset BD-I, as this deficit appears to endure into young adulthood and is associated with worse prognosis for subsequent depression and SI.

This Is Your Brain on Irritability: A Clinician's Guide to Understanding How We Know What We Know Now, and What We Need to Know in the Future, About Irritability in Children and Adolescents

Irritability is a common reason why children and adolescents are brought for psychiatric care. Although research is advancing what is known about the underlying brain and behavior mechanisms of irritability, clinicians often are shut out of that research. This article explains some of these research methods, providing brief summaries of what is known about brain/behavior mechanisms in disorders involving irritability, including bipolar disorder, disruptive mood dysregulation disorder, attention-deficit/hyperactivity disorder, and autism spectrum disorder. Greater access to these methods may help clinicians now and in the future, with such mechanisms translated into improved care, as occurs in the treatment of childhood leukemia.

Cognitive correlates of impulsive aggression in youth with pediatric bipolar disorder and bipolar offspring

BACKGROUND

Youth with bipolar disorder (BD) and offspring of individuals with BD (BD-OFF) are characterized by higher levels of impulsive and overt aggression. The cognitive basis underlying these aggressive behaviors are not clarified in this population. The aim of this study was to investigate the relationship between cognitive alterations and aggressive behavior in youth with BD and BD-OFF.

METHODS

Forty-two youth with BD, 17 BD-OFF and 57 healthy controls (HCs) were administered the Modified Overt Aggression Scale (MOAS), the Cambridge Neuropsychological Test Automated Battery (CANTAB), the Young Mania Rating Scale (YMRS) and the Children's Depression Rating Scale (CDRS). Multiple linear regression analyses were performed in the three groups separately. In each group, tests scores from the CANTAB were predictors. MOAS subscale scores and MOAS total scores were dependent variables. Results are corrected for age, IQ and mood state.

RESULTS

Both youth with BD and BD-OFF showed positive correlations between impairment in executive functions and levels of verbal aggression. In youth with BD, altered processing of either positive and negative stimuli positively correlated with MOAS total scores, whereas in BD-OFF, such relationship was negative.

CONCLUSIONS

Impulsive aggressive behaviors in youth with BD arise from a combination of altered affective processing and executive dysfunction. The negative relationship between affective processing and aggression in BD-OFF suggested the presence of possible mechanisms of resilience in this population.

Emotion regulation in pediatric bipolar disorder: A meta-analysis of published studies

BACKGROUND

Emotion regulation is a relatively recent topic in psychiatry, and has only recently begun to be tested across Pediatric Bipolar Disorder (PBD). To date, no meta-analysis has investigated the presence of emotion regulation deficits in PBD patients.

OBJECTIVES

The aim of this study is to understand where the literature stands on this topic, as well as how different researchers are measuring and grasping the concept of emotion regulation in pediatric bipolar disorders.

METHODS

A systematic search of trials using the terms ("Pediatric Bipolar Disorder") AND ("Emotion Regulation" OR "Affect Regulation" OR "Mood Lability" OR "Mood Instability" OR "Irritability") was conducted using PubMed, Google Scholar, ResearchGate, Web of Science and Psych Info databases. Of the initial 366 articles identified, 8 met eligibility criteria for the meta-analysis and were included in this study.

RESULTS

There is a statistically significant difference in Accuracy in Emotion Regulation tasks, with a tendency for lower accuracy in PBD patients; however, both groups did not differ statistically regarding Response Time.

CONCLUSION

Our data suggests that PBD patients do present emotion regulation deficits, particularly regarding facial emotion recognition and affective language interference tasks mediated by cognitive assignments. These results have important implications in developing novel psychotherapeutic interventions for this population.

Longitudinal course of depressive symptom severity among youths with bipolar disorders: Moderating influences of sustained attention and history of child maltreatment

BACKGROUND

Pediatric bipolar disorders are often characterized by disruptions in cognitive functioning, and exposure to child maltreatment (e.g., physical and sexual abuse) is associated with a significantly poorer course of illness. Although clinical and developmental research has shown maltreatment to be robustly associated with poorer cognitive functioning, it is unclear whether maltreatment and cognitive function jointly influence the clinical course of bipolar symptoms.

METHODS

This secondary analysis examined moderating effects of lifetime childhood physical and sexual abuse, and cognitive disruptions (sustained attention, affective information processing), on longitudinal ratings of depression symptom severity in youths from the Course and Outcome of Bipolar Youth (COBY) study, examined from intake (M = 12.24 years) through age 22 (N = 198; 43.9% female; Mean age of bipolar onset = 8.85 years).

RESULTS

A significant moderating effect was detected for sustained attention and maltreatment history. In the context of lower sustained attention, maltreatment exposure was associated with higher depression symptom severity during childhood, but not late adolescence. There was no association between maltreatment and symptom severity in the context of higher sustained attention, and no association between attention and depression symptom severity for non-maltreated youths.

LIMITATIONS

Depression symptom ratings at each assessment were subject to retrospective recall bias despite the longitudinal design. Cognitive assessments were administered at different ages across youths.

CONCLUSIONS

Depressive symptoms in pediatric bipolar may be jointly moderated by impairments in attention and exposure to maltreatment. Assessment of these risks, particularly in childhood, may be beneficial for considering risk of recurrence or chronicity of depressive symptoms.

White matter correlates of cognitive flexibility in youth with bipolar disorder and typically developing children and adolescents

Prior studies using behavioral tasks and neuroimaging have shown that children and adolescents with bipolar disorder (BD) have deficits in cognitive flexibility (CF)-defined as adaptation to changing rewards and punishments. However, no study, to our knowledge, has examined the white matter microstructural correlates of CF in youth with BD. To address this gap, we examined the relationship between CF assessed with the Cambridge Neuropsychological Testing Automated Battery (CANTAB)'s Intra-Extra Dimensional Set Shift task (ID/ED) and diffusion tensor imaging analyzed with FSL's preprocessing tools and Tract-Based Spatial Statistics (TBSS). We found a significantly different relationship between microstructural integrity of multiple white matter regions and CF performance in BD (n=28) and age-matched typically developing control (TDC) youths (n=26). Evaluation of the slopes of linear regressions in BD vs. TDC (ID/ED Simple Reversal error rate vs. fractional anisotropy) revealed significantly different slopes across the groups, indicating an aberrant relationship between CF and underlying white matter microstructure in youth with BD. These results underscore the importance of examining specific CF-neuroimaging relationships in BD youth. Future longitudinal studies could seek to define the white matter microstructural trajectories in BD vs. TDC, and relative to CF deficits and BD illness course.

Childhood ADHD and Early-Onset Bipolar Disorder Comorbidity: A Case Report

INTRODUCTION

Recent research has highlighted an increased rate of co-morbidity between the neurodevelopmental-behavioral disorder of attention deficit hyperactivity disorder (ADHD) and a variety of psychiatric disorders, such as mood disorders or bipolar disorder (BD). The etiology and clinical course of BD are considered to be determined by both genetic and environmental factors, either aggravating or improving.

AIM

This follow-up study of an adolescent aimed to clarify the co-morbidity between ADHD and BD. We also discuss the controversies surrounding the two diagnoses in younger populations and describe several aspects of concern regarding diagnosis, differential diagnosis, therapeutic planning/intervention, and prognosis.

METHODS

Reporting of a two-year follow-up study of a bipolar 15-year-old female patient with a previous diagnosis of ADHD during childhood.

RESULTS

Despite the occurrence of major risk factors, such as early onset and positive family history, the patient's condition rapidly remitted with medication, without relapse and/or rehospitalization during the following two years, due to the stability of her cooperation, and support of a stable and caring familial environment. Early diagnosis of BD and differential diagnoses of ADHD are considered crucial protective factors leading to an appropriate planning of treatment. In addition, parental involvement and empathic attitude towards the patient supported the latter to cooperate and comply with the treatment, enhancing positive outcomes and stability.

CONCLUSIONS

Research is required into the reliability and validity of diagnostic protocols and criteria for BD in children and adolescents, and also into the development of individualized therapeutic planning.

A Preliminary Study of the Effects of Treatment with Lithium Versus Quetiapine on Attention of Adolescents with Bipolar Disorder

Objectives: Despite attentional deficits being a prominent feature of bipolar disorder, there are limited data on the effects of common treatments for bipolar disorder on attention. Thus, we sought to compare the effects of lithium versus quetiapine on attention in adolescents with bipolar disorder. Methods: Adolescents ages 10-17 with bipolar disorder, type I, who were experiencing a manic or mixed episode, were recruited from outpatient settings and the inpatient psychiatric units at Cincinnati Children's Hospital Medical Center during their first manic episode. Healthy comparison subjects were recruited from outreach programs in the community. Patients were randomized to lithium or quetiapine, administered in a double-dummy, double-blinded manner for 6 weeks. Attentional deficits were assessed in all groups using the Identical Pairs Continuous Performance Task at baseline and at week 6. Results: Patients with bipolar disorder (n = 79) had impaired attention relative to the healthy group (n = 57) at both baseline and after 6 weeks of treatment. The lithium-treated group (n = 30) had poorer attentional performance than the healthy group at week 6. There was a difference in change in performance between lithium- and quetiapine-treated (n = 49) groups. Conclusion: Youth with bipolar disorder may have impaired attention relative to their healthy peers. Conclusions are limited by the high dropout rate in the lithium-treated group.

Neuropsychological screening with TOWI: Performance in 6- to 12-year-old children

Videogames represent an exciting development in neuropsychological assessment of cognitive function. Here, we used TOWI, a series of games based on standardized tests, to evaluate the cognitive performance of a large sample of school-age children. We compared the metrics produced by TOWI with the performance metrics reported for the standardized tests that inspired each of these tasks. We found ascending values together with age for scores reflecting correct answers and descending values together with age for scores reflecting completion times, mistakes or missed entries. Sensitivity to developmental changes, similarities with standardized tests of task metrics contribute to the validity of TOWI as a screening tool.

Executive Dysfunction and Language Deficits in a Pediatric Patient with OCD and MDD with Suicidality

The role of neuropsychiatric testing in psychiatric disorders is becoming more prominent. Neuropsychological measures that are similar across symptom domains and phenomena such as suicidality may help clinicians guide treatment and tailor therapies to the patient in the most effective way possible. We report the case of a 16-year-old girl who presented with bizarre, intrusive suicidal thoughts in the setting of OCD and MDD. This case is unusual in that we have accurate neuropsychological determination of our patient's language and executive function deficits, and we propose a link between them and her expression of suicidality in the context of OCD and MDD.

Attention Deficits in a Comorbidity-Free Sample of Euthymic Pediatric Bipolar Disorder

Attention deficits are considered one of the potential endophenotypic markers of Bipolar Disorder (BD). Pediatric bipolar disorder (PBD) likely has stronger genetic underpinnings than adult onset BD; therefore, demonstrating attention deficits in PBD can be both strategic and convincing in attesting their status as one of the potential endophenotypic markers of BD. However, unlike adult literature, uncertainty exists regarding the magnitude of attention deficits in PBD. In this regard, one key unresolved question is the potential impact of attention deficit hyperactivity disorder (ADHD). The main goal of the study was to examine attention deficits in a comorbidity-free sample of euthymic PBD patients. Thirty (21 boys, 9 girls) remitted PBD patients without co-morbidity and thirty age (<17 years), sex, handedness, and Full-Scale IQ matched control subjects were compared on performance on attention tasks. Working memory (WM), which might potentially confound with the attention task performances, was also examined. Compared to controls, PBD patients performed poorly on various tests of attention, but not on any WM tasks. Further, it was found that observed attention deficits were independent of residual mood symptoms, medication effect or illness characteristics. Such attention deficits in this comorbidity-free PBD sample further endorses its status as an endophenotypic marker of bipolar disorders and establishes continuity with deficits found in adult bipolar patients.

Genomic Analyses of Visual Cognition: Perceptual Rivalry and Top-Down Control

Visual cognition in humans has traditionally been studied with cognitive behavioral methods and brain imaging, but much less with genetic methods. Perceptual rivalry, an important phenomenon in visual cognition, is the spontaneous perceptual alternation that occurs between two distinct interpretations of a physically constant visual stimulus (e.g., binocular rivalry stimuli) or a perceptually ambiguous stimulus (e.g., the Necker cube). The switching rate varies dramatically across individuals and can be voluntarily modulated by observers. Here, we adopted a genomic approach to systematically investigate the genetics underlying binocular rivalry, Necker cube rivalry and voluntary modulation of Necker cube rivalry in young Chinese adults (Homo sapiens, 81% female, 20 ± 1 years old) at multiple levels, including common single nucleotide polymorphism (SNP)-based heritability estimation, SNP-based genome-wide association study (GWAS), gene-based analysis, and pathway analysis. We performed a pilot GWAS in 2441 individuals and replicated it in an independent cohort of 943 individuals. Common SNP-based heritability was estimated to be 25% for spontaneous perceptual rivalry. SNPs rs184765639 and rs75595941 were associated with voluntary modulation, and imaging data suggested genotypic difference of rs184765639 in the surface area of the left caudal-middle frontal cortex. Additionally, converging evidence from multilevel analyses associated genes such as PRMT1 with perceptual switching rate, and MIR1178 with voluntary modulation strength. In summary, this study discovered specific genetic contributions to perceptual rivalry and its voluntary modulation in human beings. These findings may promote our understanding of psychiatric disorders, as perceptual rivalry is a potential psychiatric biomarker.SIGNIFICANCE STATEMENT Perceptual rivalry is an important visual phenomenon in which our perception of a physically constant visual input spontaneously switches between two different states. There are individual variations in perceptual switching rate and voluntary modulation strength. Our genomic analyses reveal several loci associated with these two kinds of variation. Because perceptual rivalry is thought to be relevant to and potentially an endophenotype for psychiatric disorders, these results may help understand not only visual cognition, but also psychiatric disorders.

Vulnerabilities in sequencing and task switching in healthy youth offspring of parents with mood disorders

INTRODUCTION

Visuospatial processing and task switching are impaired in individuals with mood disorders. It is unknown whether early deficits are present before mood symptom on set or are related to risk for a specific type of mood disorder. To investigate, we compared visual attention and task switching during sequencing among never-disordered youth with parental family histories of bipolar (BD) and major depressive disorders (MDD) and healthy controls (HC) with no personal or family history of psychopathology.

METHOD

8-17-year-old youth of parents with BD (n = 31, "BD-risk"), youth of parents with MDD (n = 49, "MDD-risk"), and demographically similar HC (n = 31, "HC") were examined using the Delis-Kaplan Executive Functioning System Trail Making Test. Seed-based resting-state functional connectivity (RSFC) was collected from a subset of 88 participants (25 BD-risk, 37 MDD-risk, 26 HC) to investigate group differences in RSFC related to visuospatial processing.

RESULTS

BD-risk and MDD-risk offspring had impaired sequencing and task switching, demonstrated by reduced scores on visual scanning, F(2, 108) = 4.12, p = .02, number sequencing, F(2, 88) = 4.75, p = .01, letter sequencing, F(2, 108) = 4.24, p = .02, and number-letter sequencing, F(2, 108) = 4.66, p = .01, compared to scores in HC. RSFC between the posterior cingulate (PCC) and clusters in the subcallosal cortex, amygdala, and hippocampus significantly differed among HC, BD-risk, and MDD-risk groups. PCC-subcallosal/limbic RSFC was positively coupled in the MDD-risk and BD-risk groups and negatively coupled in HCs.

CONCLUSIONS

Youth at familial risk for mood disorders demonstrate visuospatial deficits early in the processing stream. Improved methods for identifying at-risk children with the earliest possible neurocognitive impairments may inform remediation strategies that could prevent mood disorders.

Sex differences in brain structure among adolescents with bipolar disorder

OBJECTIVES

Bipolar disorder (BD) is twice as prevalent amongst female as amongst male adolescents. Thus far, little is known regarding the neurostructural substrates underlying this disparity. We therefore examined sex differences in neurostructural magnetic resonane imaging (MRI) phenotypes amongst adolescents with BD.

METHODS

T1-weighted structural MRI was acquired from 44 BD (25 female [F] and 19 male [M]) and 58 (28 F and 30 M) healthy control (HC) adolescents (13-21 years old). Whole-brain and region-of-interest (ROI) analyses examined structural volume and cortical thickness using FreeSurfer. ROIs included the ventrolateral prefrontal cortex (vlPFC), anterior cingulate cortex (ACC), amygdala and hippocampus. General linear models evaluated sex-by-diagnosis interactions, controlling for age and intracranial volume.

RESULTS

Whole-brain analysis revealed sex-by-diagnosis interactions in the left supramarginal gyrus (SMG) (P = .02, η2  = 0.02) and right inferior parietal lobule (IPL) volumes (P = .04, η2  = 0.01). Sex differences in HCs were found in the SMG (M > F) and IPL (F > M). In BD, sex differences were reversed and of smaller magnitude in the SMG (M < F) and of greater magnitude in the IPL (F > M), driven by trends towards smaller SMG and IPL in BD vs HC male participants (P = .05 and .14). Whole-brain analyses for cortical thickness, and ROI analyses for volume and cortical thickness, were not significant.

CONCLUSIONS

Normative sex differences may be disrupted in adolescent BD in the SMG and IPL, heteromodal association network hubs responsible for higher order integration of cognitive and emotional processing. Unexpectedly, these findings may inform our understanding of aberrant brain structure in adolescent BD male patients, rather than female patients. Future work should focus on replication, as well as the impact of puberty status and sex hormones on measures of brain structure and function.

Genetic Variation in S100B Modulates Neural Processing of Visual Scenes in Han Chinese

Spatial navigation is a crucial ability for living. Previous animal studies have shown that the S100B gene is causally related to spatial navigation performance in mice. However, the genetic factors influencing human navigation and its neural substrates remain unclear. Here, we provided the first evidence that the S100B gene modulates neural processing of navigationally relevant scenes in humans. First, with a novel protocol, we demonstrated that the spatial pattern of S100B gene expression in postmortem brains was associated with brain activation pattern for spatial navigation in general, and for scene processing in particular. Further, in a large fMRI cohort of healthy adults of Han Chinese (N = 202), we found that S100B gene polymorphisms modulated scene selectivity in the retrosplenial cortex (RSC) and parahippocampal place area. Finally, the serum levels of S100B protein mediated the association between S100B gene polymorphism and scene selectivity in the RSC. Our study takes the first step toward understanding the neurogenetic mechanism of human spatial navigation and suggests a novel approach to discover candidate genes modulating cognitive functions.

Are patients with bipolar disorder and comorbid attention-deficit hyperactivity disorder more neurocognitively impaired?

OBJECTIVE

Research on neurocognitive impairment in adult patients with comorbid bipolar disorder (BD) and attention-deficit hyperactivity disorder (ADHD) is very scarce. This study assessed the neurocognitive profile of a comorbid group (BD+ADHD) compared with that of pure BD (pBD) group, pure ADHD (pADHD) group and healthy controls (HCs).

METHODS

This was a three-site study comprising 229 subjects: 70 patients with pBD, 23 with BD+ADHD, 50 with pADHD, and 86 HCs. All patients with BD had been euthymic for at least 6 months. Neuropsychological performance was assessed using a comprehensive neurocognitive battery.

RESULTS

Our results showed that all the clinical groups had poorer performance than the HCs in all the neurocognitive domains except for executive functions. No significant differences were observed between the pBD and BD+ADHD groups in any of the cognitive domains, with these two groups showing greater impairment than the pADHD group in executive functions and visual memory.

CONCLUSIONS

Our results, although preliminary, suggest that the BD+ADHD group showed the same neurocognitive profile as pBD patients, most likely reflecting the same neurobiological basis. On the other hand, the pADHD group showed a more selective moderate impairment in attention.

Retinal photography: A window into the cardiovascular-brain link in adolescent bipolar disorder

OBJECTIVE

The burden of cardiovascular disease in bipolar disorder (BD) exceeds what can be explained by traditional cardiovascular risk factors (CVRFs), lifestyle, and/or medications. Moreover, neurocognitive deficits are a core feature of BD, and are also related to CVRFs. We examined retinal vascular photography, a proxy for cerebral microvasculature, in relation to CVRFs, peripheral microvascular function, and neurocognition among BD adolescents.

METHODS

Subjects were 30 adolescents with BD and 32 healthy controls (HC). Retinal photography was conducted using a Topcon TRC 50 DX, Type IA camera, following pupil dilation. Retinal arteriolar and venular caliber was measured, from which the arterio-venular ratio (AVR) was computed. All measures were conducted masked to participant diagnosis. Peripheral arterial tonometry measured endothelial function. Neurocognition was assessed using the Cambridge Neuropsychological Tests Automated Battery.

RESULTS

AVR was not significantly different between groups (Cohen's d=0.18, p=0.103). Higher diastolic blood pressure (BP) was associated with lower (worse) AVR in BD (r=-0.441, p=0.015) but not HC (r=-0.192, p=0.293). Similarly, in the BD group only, higher (better) endothelial function was associated with higher AVR (r=0.375, p=0.041). Hierarchical regression models confirmed that, independent of covariates, retinal vascular caliber was significantly associated with diastolic BP and endothelial function in BD. Within the BD group, mood scores were significantly negatively correlated with AVR (β=-0.451, p=0.044).

LIMITATIONS

This study's limitations include a small sample size, a cross-sectional study design, and a heterogeneous sample.

CONCLUSION

Retinal photography may offer unique insights regarding the cardiovascular and neurocognitive burden of BD. Larger longitudinal studies are warranted.

Cognitive Impairment in Euthymic Pediatric Bipolar Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

To perform a systematic review and meta-analysis of studies investigating neurocognition in euthymic youths with bipolar disorder (BD) compared to healthy controls (HCs).

METHOD

A systematic literature search was conducted in the PubMed/MEDLINE, PsycINFO, and EMBASE databases from inception up until March 23, 2016, for original peer-reviewed articles that investigated neurocognition in euthymic youths with BD compared to HCs. Effect sizes (ES) for individual tests were extracted. In addition, results were grouped according to cognitive domain. This review complied with the PRISMA statement guidelines.

RESULTS

A total of 24 studies met inclusion criteria (N = 1,146; 510 with BD). Overall, euthymic youths with BD were significantly impaired in verbal learning, verbal memory, working memory, visual learning, and visual memory, with moderate to large ESs (Hedge's g 0.76-0.99); significant impairments were not observed for attention/vigilance, reasoning and problem solving, and/or processing speed. Heterogeneity was moderate to large (I² ≥ 50%) for most ES estimates. Differences in the definition of euthymia across studies explained the heterogeneity in the ES estimate for verbal learning and memory. We also found evidence for other potential sources of heterogeneity in several ES estimates including co-occurring attention-deficit/hyperactivity disorder (ADHD) and anxiety disorders, and the use of medications. In addition, the use of different neuropsychological tests appeared to contribute to heterogeneity of some estimates (e.g., attention/vigilance domain).

CONCLUSION

Euthymic youths with BD exhibit significant cognitive dysfunction encompassing verbal learning and memory, working memory, and/or visual learning and memory domains. These data indicate that for a subset of individuals with BD, neurodevelopmental factors may contribute to cognitive dysfunction.

Association of Lipid Peroxidation and Brain-Derived Neurotrophic Factor with Executive Function in Adolescent Bipolar Disorder

BACKGROUND

Executive dysfunction is common and impairing in youth bipolar disorder (BD), and oxidative stress (OS) and brain-derived neurotrophic factor (BDNF) have been implicated in executive deficits of adult BD. This study aimed to determine the association between OS and executive dysfunction in BD adolescents and the influence of BDNF on this association.

METHODS

Serum levels of lipid hydroperoxides (LPH) and 4-hydroxy-2-nonenal (4-HNE) and BDNF levels were measured in 29 BD and 25 control adolescents. The intra-extra-dimensional (IED) set-shifting task assessed executive function. Lower IED scores indicated better performance. High and low BDNF subgroups were defined by median split.

RESULTS

IED Z-scores were impaired in the BD group compared to controls, whereas biomarker levels were not significantly different between groups. LPH-BDNF correlations were significantly different between BD and controls (Z = 2.046, p = 0.041). In high BDNF BD subjects, LPH was significantly positively correlated with IED completed stage trials (ρ = 0.755, p = 0.001) and pre-extra-dimensional shift errors (ρ = 0.588, p = 0.017). Correlations were opposite in controls. In a linear model, LPH, BDNF, and the LPH-BDNF interaction each significantly explained variance of IED total trials (adjusted) (model r ² = 0.187, F = 2.811, p = 0.035).

CONCLUSIONS

There is a negative association between LPH and executive function in BD adolescents, which may be modulated by BDNF. LPH and BDNF may be useful biomarkers of executive function in BD. These findings highlight the importance of examining multiple peripheral biomarkers in relation to cognitive functions in BD adolescents. Future studies should explore these factors in longitudinal designs to determine the directionality of observed associations.

Neurocognition and psychosocial functioning in adolescents with bipolar disorder

BACKGROUND

Adults with bipolar disorder demonstrate significantly poorer psychosocial functioning and neurocognition compared to controls. In adult bipolar disorder neurocognition predicts a substantial portion of variance in functioning. Adolescents with bipolar disorder have reducedpsychosocial functioning, but less is known about neurocognitive impairments, and no studies have examined the relationship between neurocognition and functioning in an adolescent sample.

METHODS

38 adolescents with bipolar disorder and 49 healthy controls under 20 years of age completed assessments of psychosocial functioning, neurocognitive ability, and psychiatric symptoms.

RESULTS

Adolescents with bipolar disorder had significantly poorer psychosocial functioning in domains of daily activities, social functioning, and satisfaction with functioning, ps<.006, compared to healthy controls. They also had poorer general neurocognitive functioning than controls, p=.004, with the greatest impairment on a test of sustained attention. Neurocognition was not a significant predictor of psychosocial functioning in this sample, but depressive symptoms significantly predicted functioning in all domains, p<.033.

LIMITATIONS

Limited sample size did not allow for complex statistical analyses. Differences in demographic characteristics of the clinical and control groups may limit generalization of these results.

CONCLUSIONS

This adolescent sample with bipolar disorder experiences significantly poorer neurocognitive and psychosocial functioning compared to controls; however, psychosocial functioning appears to be more strongly related to mood symptoms than to neurocognition. Future work is needed to delineate the time course of neurocognitive functioning and its relation to psychosocial functioning across the course of illness. Adolescence may provide an ideal time for cognitive enhancement and intensive psychosocial intervention.

Verbal Memory Abilities in Severe Childhood Psychiatric Disorders and the Influence of Attention and Executive Functions

Despite prior adult research regarding the influence of executive functions on memory performance, there has been inconsistent prior research on the role of executive functions on memory performance in children, particularly those children with severe psychiatric disorders. A medical chart review was conducted for 76 children (ages 6-12 years) who received a neuropsychological evaluation during children's psychiatric inpatient program hospitalization. A series of hierarchical regression analyses investigated the role of attention/executive and non-executive functions in verbal memory performance (immediate recall, delayed recall, and delayed recognition). Demographic and verbal measures were entered into blocks 1 and 2 for all analyses, followed by attention and executive functions (i.e., attention span, sustained attention, verbal fluency, cognitive flexibility, inhibitory control, and planning/organization). Nearly 15% of the participants displayed memory impairment. Results of regression analyses indicated attention/executive dysfunction severity predicted overall memory performance. Attention span predicted performance on all three memory conditions. Planning/organization accounted for unique variance in immediate recall condition while inhibitory control accounted for unique variance in delayed recall condition. These results indicate that verbal memory problems frequently occur in severe childhood psychiatric disorders. Further, planning/organization deficits may influence immediate recall, while inhibitory control deficits may influence delayed recall. Alternatively, delayed recognition memory may be the most resistant to the negative influence of executive deficits on verbal memory performance in childhood psychiatric disorders.

Auditory Vigilance and Working Memory in Youth at Familial Risk for Schizophrenia or Affective Psychosis in the Harvard Adolescent Family High Risk Study

BACKGROUND

The degree of overlap between schizophrenia (SCZ) and affective psychosis (AFF) has been a recurring question since Kraepelin's subdivision of the major psychoses. Studying nonpsychotic relatives allows a comparison of disorder-associated phenotypes, without potential confounds that can obscure distinctive features of the disorder. Because attention and working memory have been proposed as potential endophenotypes for SCZ and AFF, we compared these cognitive features in individuals at familial high-risk (FHR) for the disorders.

METHODS

Young, unmedicated, first-degree relatives (ages, 13-25 years) at FHR-SCZ (n=41) and FHR-AFF (n=24) and community controls (CCs, n=54) were tested using attention and working memory versions of the Auditory Continuous Performance Test. To determine if schizotypal traits or current psychopathology accounted for cognitive deficits, we evaluated psychosis proneness using three Chapman Scales, Revised Physical Anhedonia, Perceptual Aberration, and Magical Ideation, and assessed psychopathology using the Hopkins Symptom Checklist -90 Revised.

RESULTS

Compared to controls, the FHR-AFF sample was significantly impaired in auditory vigilance, while the FHR-SCZ sample was significantly worse in working memory. Both FHR groups showed significantly higher levels of physical anhedonia and some psychopathological dimensions than controls. Adjusting for physical anhedonia, phobic anxiety, depression, psychoticism, and obsessive-compulsive symptoms eliminated the FHR-AFF vigilance effects but not the working memory deficits in FHR-SCZ.

CONCLUSIONS

The working memory deficit in FHR-SZ was the more robust of the cognitive impairments after accounting for psychopathological confounds and is supported as an endophenotype. Examination of larger samples of people at familial risk for different psychoses remains necessary to confirm these findings and to clarify the role of vigilance in FHR-AFF. (JINS, 2016, 22, 1026-1037).

Neurocognitive Phenotypes in Severe Childhood Psychiatric Disorders

This study investigated the presence of potential neurocognitive phenotypes within a severe childhood psychiatric sample. A medical chart review was conducted for 106 children who received a neuropsychological evaluation during children's psychiatric inpatient program hospitalization. A hierarchical cluster analysis was conducted to identify distinct clinical clusters based on neurocognitive measures. Cluster analysis identified four distinct clusters, subsequently labeled neurocognitive phenotypes: "intact cognition" (27%), "global dysfunction" (20%), "organization/planning" (21%), and "inhibition-memory" (32%). Significant differences were identified in history of legal involvement and antipsychotic medications at hospital admission. Differences between none-minimal and moderate-high neurocognitive dysfunction were identified in age, amount of diagnoses and antipsychotic medications at admission, and hospital length of stay. Current findings provide preliminary evidence of underlying neurocognitive phenotypes within severe childhood psychiatric disorders. Findings highlight the importance of neuropsychological evaluation in the treatment of childhood psychiatric disorders.

Reversal-learning deficits in childhood-onset bipolar disorder across the transition from childhood to young adulthood

BACKGROUND

Bipolar disorder (BD) is a severe mental illness that can have high costs for youths (<18 years old) and adults. Relative to healthy controls (HC), individuals with BD often show impaired attention, working memory, executive function, and cognitive flexibility (the ability to adapt to changing reward/punishment contingencies). In our study of youths and young adults with BD, we investigated 1) how cognitive flexibility varies developmentally in BD, and 2) whether it is independent of other executive function deficits associated with BD.

METHODS

We measured errors on a reversal-learning task, as well as spatial working memory and other executive function, among participants with BD (N=75) and HC (N=130), 7-27 years old. Regression analyses focused on the effects of diagnosis on reversal-learning errors, controlling for age, gender, IQ, spatial span, and executive function. Similar analyses examined non-reversal errors to rule out general task impairment.

RESULTS

Participants with BD, regardless of age, gender, or cognitive ability, showed more errors than HC on the response reversal stages of the cognitive flexibility task. However, participants with BD did not show more errors on non-reversal stages, even when controlling for other variables.

LIMITATIONS

Study limitations include the cross-sectional, rather than longitudinal, design; inability to measure non-linear age effects; and inclusion of medicated participants and those with psychiatric comorbidity.

CONCLUSIONS

Individuals with BD show a specific impairment in reversing a previously rewarded response, which persists across the transition from childhood to young adulthood. Tailored interventions targeting this deficit may be effective throughout this developmentally turbulent time.

Cognitive flexibility and performance in children and adolescents with threshold and sub-threshold bipolar disorder

Greater understanding of cognitive function in children and adolescents with bipolar disorder (BD) is of critical importance to improve our ability to design targeted treatments to help with real-world impairment, including academic performance. We sought to evaluate cognitive performance among children with either BD type I, II, or "not otherwise specified" (NOS) participating in multi-site Course and Outcome of Bipolar Youth study compared to typically developing controls (TDC) without psychopathology. In particular, we sought to test the hypothesis that BD-I and BD-II youths with full threshold episodes of mania or hypomania would have cognitive deficits, including in reversal learning, vs. those BD-NOS participants with sub-threshold episodes and TDCs. N = 175 participants (BD-I = 81, BD-II = 11, BD-NOS = 28, TDC = 55) completed Cambridge Neuropsychological Automated Testing Battery (CANTAB) tasks. A priori analyses of the simple reversal stage of the CANTAB intra-/extra-dimensional shift task showed that aggregated BD-I/II participants required significantly more trials to complete the task than either BD-NOS participants with sub-syndromal manic/hypomanic symptoms or than TDCs. BD participants across sub-types had impairments in sustained attention and information processing for emotionally valenced words. Our results align with prior findings showing that BD-I/II youths with distinct episodes have specific alterations in reversal learning. More broadly, our study suggests that further work is necessary to see the interaction between neurocognitive performance and longitudinal illness course. Additional work is required to identify the neural underpinnings of these differences as targets for potential novel treatments, such as cognitive remediation.

IMPAIRED EXECUTIVE FUNCTIONING IN PEDIATRIC TRICHOTILLOMANIA (HAIR PULLING DISORDER)

BACKGROUND

No neurocognitive examinations of pediatric trichotillomania (hair pulling disorder; HPD) have taken place. As a result, science's understanding of the underlying pathophysiology associated with HPD in youths is greatly lacking. The present study seeks to begin to address this gap in the literature via examination of executive functioning in a stimulant-free sample of children with HPD.

METHODS

Sixteen and 23 children between 9 and 17 years of age meeting DSM-5 diagnostic criteria for HPD or classified as a healthy control, respectively, were recruited (N = 39) to complete structured interviews, self-reports, and a subset of tests from the Cambridge Automatic Neurocognitive Test Assessment Battery (CANTAB) assessing cognitive flexibility/reversal learning (intradimensional/extradimensional; IED), working memory (spatial span; SSP), and planning and organization (Stocking of Cambridge; SOC).

RESULTS

Hierarchical regression analyses indicated that, after controlling for appropriate covariates, diagnostic status predicted impaired performance on both the IED (reversal learning only) and SOC (planning and organization) but failed to predict cognitive flexibility or working memory capacity. Correlational analyses revealed that pulling severity was strongly related to working memory capacity, while disparate relationships between pulling styles (automatic, focused pulling) were evident with respect to working memory and planning and organization.

CONCLUSIONS

Children with HPD performed more poorly on tasks of executive functioning as compared to controls. Correlational analyses suggest potentially distinct pathophysiology underlying automatic and focused pulling warranting further research. Limitations and future areas of inquiry are discussed.

Associations of age with reward delay discounting and response inhibition in adolescents with bipolar disorders

OBJECTIVES

Bipolar disorders' (BD) onset before age 18 is a potential marker for a more severe illness course. Adolescence is also a period of significant normative maturation of inhibitory control and reward-relevant decision-making processes, such as decreased delay discounting (i.e., decreased preference for smaller, immediate versus larger, delayed rewards). Adults with BD exhibit elevated delay discounting rates. Very little is known about developmental changes in delay discounting in adolescents with BD, or about associations between inhibitory control and delay discounting in BD. The present study addresses these questions.

METHODS

The sample included 78 participants, ages 13 to 23, with BD or without history of mental illness. Group differences and group by age interaction effects on delay discounting (32 BD, 32 controls with valid responses), probability discounting (34 BD, 37 controls) and inhibitory control indices (34 BD, 38 controls) were assessed.

RESULTS

Among healthy controls, less discounting of delayed rewards was associated with older age, whereas adolescents with BD did not show age-related associations. There were no group differences in probability discounting or inhibitory control.

LIMITATIONS

The cross-sectional nature of the study cannot fully rule out the less likely interpretation of group differences in cohort effects.

CONCLUSIONS

The lack of age-related improvement in delay tolerance in BD suggests disrupted development of executive control processes within reward contexts, which in turn may contribute to understanding more severe course of pediatric onset BD. Longitudinal studies are needed to examine delay discounting in relation to maturation of neural reward systems among adolescents with BD.

Cognitive Flexibility and Social Responsiveness in Children and Adolescents with Tourette Syndrome

This study examined cognitive flexibility and social responsiveness in children and adolescents with Tourette Syndrome (TS). Thirty one subjects with TS were compared to 32 age-matched healthy controls. Assessments included semi-structured interviews to assess psychopathology, parent-rated Social Responsiveness Scale (SRS) and a brief neuropsychological battery selected as measures of cognitive flexibility. Completion time for both Trail Making Tests (TMT-A and TMT-B) were significantly longer for TS group than controls, however the difference in perseverative errors on Wisconsin Card Sorting Test (WCST) was not significant. SRS total score was significantly higher in the TS group compared to controls, indicating greater impairment in social responsiveness. Group difference for TMTs and SRS failed to reach significance after controlling for co-occurring conditions. Clinicians might consider social impairment in the evaluation plan of children and adolescents with Tourette syndrome.

Cognitive remediation: potential novel brain-based treatment for bipolar disorder in children and adolescents

Bipolar disorder (BD) is among the most impairing psychiatric disorders affecting children and adolescents, despite our best psychopharmacological and psychotherapeutic treatments. Cognitive remediation, defined as a behavioral intervention designed to improve cognitive functions so as to reduce psychiatric illness, is an emerging brain-based treatment approach that has thus far not been studied in pediatric BD. The present article reviews the basic principles of cognitive remediation, describes what is known about cognitive remediation in psychiatric disorders, and delineates potential brain/behavior alterations implicated in pediatric BD that might be targets for cognitive remediation. Emerging data show that cognitive remediation may be useful in children and adults with schizophrenia, ADHD, and anxiety disorders, and in adults with BD. Potential targets for cognitive remediation in pediatric BD include face processing, response inhibition, frustration, and cognitive flexibility. Further study is warranted to determine if cognitive remediation for these targets, or others, may serve as a novel, brain-based treatment for pediatric BD.

The rat's not for turning: Dissociating the psychological components of cognitive inflexibility

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Non-rewarded or irrelevant prior associations are important for flexible responding.

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Associations of reward and non-reward in reversal learning are neurally dissociable.

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Disruption of prior irrelevant or rewarded associations cause pathological deficits.

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Experimental paradigms of cognitive flexibility can be improved to aid translation.

Executive function is commonly assessed by assays of cognitive flexibility such as reversal learning and attentional set-shifting. Disrupted performance in these assays, apparent in many neuropsychiatric disorders, is frequently interpreted as inability to overcome prior associations with reward.

However, non-rewarded or irrelevant associations may be of considerable importance in both discrimination learning and cognitive flexibility. Non-rewarded associations can have greater influence on choice behaviour than rewarded associations in discrimination learning. Pathology-related deficits in cognitive flexibility can produce selective disruptions to both the processing of irrelevant associations and associations with reward. Genetic and pharmacological animal models demonstrate that modulation of reversal learning may result from alterations in either rewarded or non-rewarded associations.

Successful performance in assays of cognitive flexibility can therefore depend on a combination of rewarded, non-rewarded, and irrelevant associations derived from previous learning, accounting for some inconsistencies observed in the literature. Taking this combination into account may increase the validity of animal models and may also reveal pathology-specific differences in problem solving and executive function.

Comorbidity in pediatric bipolar disorder: prevalence, clinical impact, etiology and treatment

BACKGROUND

Research on pediatric bipolar disorder (PBD) is providing a plethora of empirical findings regarding its comorbidity. We addressed this question through a systematic review concerning the prevalence, clinical impact, etiology and treatment of main comorbid disorders involved.

METHOD

A comprehensive database search was performed from 1990 to August 2014. Overall, 167 studies fulfilled the inclusion criteria.

RESULTS

Bipolar youth tend to suffer from comorbid disorders, with highest weighted mean prevalence rate arising from anxiety disorders (54%), followed by attention deficit hyperactivity disorder (ADHD) (48%), disruptive behavior disorders (31%), and substance use disorders (SUD) (31%). Furthermore, evidence indicates that ADHD and anxiety disorders negatively affect the symptomatology, neurocognitive profile, clinical course and the global functioning of PBD. Likewise, several theories have been posited to explain comorbidity rates in PBD, specifically common risk factors, one disorder being a risk factor for the other and nosological artefacts. Lastly, randomized controlled trials highlight a stronger therapeutic response to stimulants and atomoxetine (vs. placebo) as adjunctive interventions for comorbid ADHD symptoms. In addition, research focused on the treatment of other comorbid disorders postulates some benefits from mood stabilizers and/or SGA.

LIMITATIONS

Epidemiologic follow-up studies are needed to avoid the risk of nosological artefacts. Likewise, more research is needed on pervasive developmental disorders and anxiety disorders, especially regarding their etiology and treatment.

CONCLUSIONS

Psychiatric comorbidity is highly prevalent and is associated with a deleterious clinical effect on pediatric bipolarity. Different etiological pathways may explain the presence of these comorbid disorders among bipolar youth. Standardized treatments are providing ongoing data regarding their effectiveness for these comorbidities among bipolar youth.

The neurocognitive functioning in bipolar disorder: a systematic review of data

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.

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.

Reward dysregulation and mood symptoms in an adolescent outpatient sample

Research on bipolar spectrum disorders (BPSD) in adolescence has burgeoned in the last decade, but continued work is needed to identify endophenotypic markers associated with illness onset and course. The present study examined reward dysregulation--measured via the behavioral activation system (BAS)--as one putative marker of BPSD in adolescence. A diverse group of 425 outpatient adolescents between 11 and 17 years of age (52 % male) completed the Behavioral Inhibition and Activation Scale (BIS-BAS) scale to measure reward dysregulation. Semi-structured interviews determined diagnoses and severity of mood symptoms. Parent-reported BAS was associated with increased symptoms of mania, and parent and adolescent-reported BAS were associated with symptoms of depression. Parent-reported BIS scores were associated with increased symptoms of mania. Results held independent of diagnostic status. Furthermore, parent BIS/BAS reports were stronger predictors for manic symptoms compared to adolescent-reports. Results extend work in adults with BPSD, suggesting a transdiagnostic association between reward dysregulation and mood symptom severity in adolescence.

A developmental study on the neural circuitry mediating response flexibility in bipolar disorder

Cross-sectional neuroimaging studies are an important first step in examining developmental differences in brain function between adults and youth with bipolar disorder (BD). Impaired response flexibility may contribute to reduced ability to modify goal-directed behavior in BD appropriately. We compared neural circuitry mediating this process in child (CBD) vs. adult BD (ABD) and age-matched healthy subjects. fMRI data from 15 CBD, 23 ABD, 20 healthy children, and 27 healthy adults were acquired during a response flexibility paradigm, a task where subjects inhibit a prepotent response and execute an alternative response. When successfully executing an alternate response, CBD showed frontal, parietal, and temporal hyperactivation relative to healthy children and ABD, while ABD hypoactivated these regions relative to healthy adults. Previous studies of response flexibility in healthy volunteers revealed frontal, temporal, and parietal cortex hyperactivation in children and hypoactivation in adults. Relative to age-matched healthy subjects, we found hyperactivation in these regions in CBD and hypoactivation in ABD. This suggests that our findings in patients may represent the extreme extension of the age-related response flexibility activation differences found in healthy subjects. Future studies should use longitudinal fMRI to examine the developmental trajectory of the neural circuitry mediating response flexibility in BD.

Family functioning deficits in bipolar disorder and ADHD in youth

BACKGROUND

Rates of diagnosis and treatment for bipolar disorder (BD) in youth continue to rise. Researchers and clinicians experience difficulty differentiating between BD in youth and other conditions that are commonly comorbid or share similar clinical features with BD, especially attention-deficit/hyperactivity disorder (ADHD). Comparative studies of the phenomenology and psychosocial correlates of these conditions help to address this. Family functioning is an important topic for both BD and ADHD since both are associated with numerous family-related deficits. One previous study suggested that manic/hypomanic youths'family functioning differed from ADHD and typically developing control (TDC) groups. However, many family functioning studies with BD and ADHD youth have methodological limitations or fail to use comprehensive, validated measures.

METHODS

This investigation used adolescent report on the Family Assessment Device (FAD), based on the McMaster Model of family functioning. Youth were recruited in BD (n=30), ADHD (n=36), and TDC (n=41) groups.

RESULTS

Groups were similar on most demographic variables, but The TDC group scored somewhat higher than the others on IQ and socioeconomic status. FAD results indicated that BD and ADHD groups scored worse than TDC on the General Functioning and Roles scales of the FAD. In addition, the BD group showed impairment on the Problem Solving scale relative to TDC.

LIMITATIONS

sample size, lack of parent report, ADHD comorbidity in BD group.

CONCLUSIONS

Family functioning deficits distinguish both clinical groups from TDC, and problem-solving dysfunction may be specific to BD. These findings may apply to treatment models for both conditions.

The contingent negative variation in remitted paediatric bipolar patients: no evidence of abnormality

Although the Contingent Negative Variation (CNV) paradigm has been useful in schizophrenia, limited research involving such paradigm in subjects with Bipolar Disorder (BD) has produced contradictory findings. To the best of our knowledge, no study has investigated CNV in Paediatric Bipolar Disorder (PBD) subjects. Thirty remitted PBD patients and thirty matched healthy control group subjects participated in the study. No significant between group main effect could be found for either CNV latency or amplitude. We propose that CNV is unlikely to be a true endophenotype of BD. However, absence of CNV finding during euthymic phase in BD may help us in advancing our understanding of BD and such finding may, in fact, have some specificity with regard to differentiating BD from schizophrenia.

Genetic and neurocognitive foundations of emotion abnormalities in bipolar disorder

INTRODUCTION

Bipolar Disorder (BD) is a serious mood disorder, the aetiology of which is still unclear. The disorder is characterised by extreme mood variability in which patients fluctuate between markedly euphoric, irritable, and elevated states to periods of severe depression. The current research literature shows that BD patients demonstrate compromised neurocognitive ability in addition to these mood symptoms. Viable candidate genes implicated in neurocognitive and socioemotional processes may explain the development of these core emotion abnormalities. Additionally, links between faulty neurocognition and impaired socioemotional ability complement genetic explanations of BD pathogenesis. This review examines associations between cognition indexing prefrontal neural regions and socioemotional impairments including emotion processing and regulation. A review of the effect of COMT and TPH2 on these functions is also explored.

METHODS

Major computer databases including PsycINFO, Google Scholar, and Medline were consulted in order to conduct a comprehensive review of the genetic and cognitive literature in BD.

RESULTS

This review determines that COMT and TPH2 genetic variants contribute susceptibility to abnormal prefrontal neurocognitive function which oversees the processing and regulation of emotion. This provides for greater understanding of some of the emotional and cognitive symptoms in BD.

CONCLUSIONS

Current findings in this direction show promise, although the literature is still in its infancy and further empirical research is required to investigate these links explicitly.

Negative emotion impairs working memory in pediatric patients with bipolar disorder type I

BACKGROUND

We investigated affect recognition and the impact of emotional valence on working memory (using happy, angry, and neutral faces) in pediatric patients with bipolar disorder (BD) and healthy control (HC) subjects.

METHOD

Subjects (N=70) consisted of unmedicated patients with BD type I (BD I, n=23) and type II (BD II, n=16) and matched HC subjects (n=31). All subjects completed tasks of emotion recognition (Chicago Pediatric Emotional Acuity Task; Chicago PEAT) and working memory for happy, angry, and neutral faces (Affective N-Back Memory Task; ANMT).

RESULTS

Compared to HC subjects, BD patients performed significantly more poorly when identifying the intensity of happy and angry expressions on the Chicago PEAT, and demonstrated working-memory impairments regardless of the type of facial emotional stimuli. Pediatric BD patients displayed the most impaired accuracy and reaction time performance with negative facial stimuli relative to neutral stimuli, but did not display this pattern with positive stimuli. Only BD I patients displayed working-memory deficits, while both BD I and BD II patients displayed emotion-identification impairments. Results remained significant after controlling for co-morbid ADHD and mood state.

CONCLUSIONS

Both BD I and BD II youth demonstrate emotion-identification deficits. BD youth also demonstrate working-memory impairments for facial stimuli irrespective of emotional valence; however, working-memory deficits were the most pronounced with negative emotional stimuli. These deficits appear to be specific to BD I patients, and suggest therefore that a more severe form of illness is characterized by more severe social-cognitive impairment.

Reduced functional connectivity of prefrontal regions and amygdala within affect and working memory networks in pediatric bipolar disorder

This study examined whether adolescents with pediatric bipolar disorder (PBD) have abnormal regional functional connectivity in distributed brain networks during an affective working memory task. Adolescents with PBD (n=41) and healthy controls (HC; n=16) performed a two-back functional magnetic resonance imaging working memory task with blocks of either angry or neutral faces. Independent component analysis methodology identified two temporally independent and functionally connected brain networks that showed differential functional connectivity in PBD and HC. Within a network for "affect evaluation and regulation," PBD showed decreased functional connectivity relative to HC in regions involved in emotion processing such as the right amygdala, and in emotion regulation regions such as the right ventrolateral prefrontal cortex (VLPFC), while functional connectivity was increased in emotion evaluation regions such as the bilateral medial PFC. Furthermore, in an "Affective Working Memory Network," PBD exhibited greater connectivity relative to HC in left dorsolateral PFC (DLPFC), caudate, and right VLPFC; and simultaneously reduced connectivity in emotion processing regions, such as the right amygdala, bilateral temporal regions, and the junction of DLPFC/VLPFC, which interfaces affective and cognitive processes. Dysfunction in network engagement in PBD patients illustrates that they are expending greater effort in face emotion evaluation, while being less able to engage affect regulation regions.

Cognitive dysfunction is worse among pediatric patients with bipolar disorder Type I than Type II

BACKGROUND

  Impaired profiles of neurocognitive function have been consistently demonstrated among pediatric patients with bipolar disorder (BD), and may aid in the identification of endophenotypes across subtypes of the disorder. This study aims to determine phenotypic cognitive profiles of patients with BD Type I and II.

METHODS

  Subjects (N = 79) consisted of BD I (n = 27) and BD II (n = 19) patients and demographic and intellectually matched healthy controls (HC; n = 33) that completed a battery of neurocognitive tasks.

RESULTS

  Bipolar disorder Type I patients performed significantly more poorly compared to HC on all domains of cognitive function including attention, executive function, working memory, visual memory, and verbal learning and memory. BD I patients also performed more poorly compared to BD II patients on all domains of cognitive functioning with the exception of working memory, whereas BD II patients did poorly relative to HC only on verbal learning and memory.

CONCLUSIONS

  Findings from the current study indicate that BD I patients are characterized by more severe cognitive impairment relative to BD II patients who show an intermediate pattern of performance between BD I patients and HC. Verbal learning and memory may effectively differentiate pediatric BD patients and controls, regardless of the subtype of BD, and may serve as a cognitive endophenotype for the disorder. Additionally, these findings move us closer to developing effective cognitive interventions tailored to specific subtypes of pediatric BD patients.

Sensitivity to positive and negative feedback in euthymic patients with bipolar I disorder: the last episode makes the difference

OBJECTIVES

It is unclear whether abnormalities in cognition and motivation, such as altered feedback processing, observed during euthymia represent trait markers of bipolar I disorder (BD-I) or scars from previous episodes that also occur in major depression (MD). The present research examines how previous episodes influence sensitivity to positive and negative feedback, applying multiple hierarchical regression analysis with number of past depressive and manic episodes, residual mood symptoms, affective quality of the last episode, time in remission, medication, illness severity, and age as predictors.

METHODS

The study included 23 euthymic patients with BD-I, 19 remitted patients with MD, and 19 healthy persons who underwent a task which discriminates whether persons learn better from negative or positive feedback.

RESULTS

For both models, predicting sensitivity to positive [F((5,60)) = 6.50, p = 0.001, adjusted R(2) = 0.22] and negative feedback [F((5,60)) = 5.12, p = 0.001, adjusted R(2) = 0.22], the quality of the last affective episode was the only significant predictor. BD-I patients who last experienced a manic episode learned well from positive but not negative feedback, whereas BD-I patients who last experienced a depressive episode showed the opposite pattern.

CONCLUSIONS

Our data identify differences in response to positive and negative consequences carrying over into the euthymic state that are qualitatively related to the polarity of the preceding episode, whereas other disease-related variables had no significant influence. This sheds new light on previous inconsistent data in euthymic BD-I patients and could also guide tailored treatment.