Sustained attention deficit in bipolar disorder

Supra-second interval timing in bipolar disorder: examining the role of disorder sub-type, mood, and medication status

BACKGROUND

Widely reported by bipolar disorder (BD) patients, cognitive symptoms, including deficits in executive function, memory, attention, and timing are under-studied. Work suggests that individuals with BD show impairments in interval timing tasks, including supra-second, sub-second, and implicit motor timing compared to the neuronormative population. However, how time perception differs within individuals with BD based on disorder sub-type (BDI vs II), depressed mood, or antipsychotic medication-use has not been thoroughly investigated. The present work administered a supra-second interval timing task concurrent with electroencephalography (EEG) to patients with BD and a neuronormative comparison group. As this task is known to elicit frontal theta oscillations, signal from the frontal (Fz) lead was analyzed at rest and during the task.

RESULTS

Results suggest that individuals with BD show impairments in supra-second interval timing and reduced frontal theta power during the task compared to neuronormative controls. However, within BD sub-groups, neither time perception nor frontal theta differed in accordance with BD sub-type, depressed mood, or antipsychotic medication use.

CONCLUSIONS

This work suggests that BD sub-type, depressed mood status or antipsychotic medication use does not alter timing profile or frontal theta activity. Together with previous work, these findings point to timing impairments in BD patients across a wide range of modalities and durations indicating that an altered ability to assess the passage of time may be a fundamental cognitive abnormality in BD.

Clinical neuropsychological characteristics of bipolar disorder, with a focus on cognitive and linguistic pattern: a conceptual analysis

Neuropsychology is an academic discipline that investigates the intricate interplay between the brain, mind, and behavior. It accomplishes this by examining the underlying structure and activities of the brain, with a particular focus on psychological phenomena such as language, motivation, memory, attention, thinking, consciousness, learning, and efficacy. The assessment of neuropsychological changes in individuals diagnosed with bipolar disorder has received limited attention in comparison to other psychiatric conditions, such as schizophrenia, for instance. Nevertheless, there has been a growing interest in the etiological implications, therapies, preventions, and prognostic factors related to social competence and the quality of life of patients. The objective of this review is to compile and analyze the existing research conducted thus far on the association between cognitive abnormalities and bipolar disorder. This study has examined research conducted across many stages of the condition, including depression and mania. Additionally, it has explored comparative studies involving people with schizophrenia, as well as the potential impact of psychopharmaceutical interventions.

Prefrontal, parietal, and limbic condition-dependent differences in bipolar disorder: a large-scale meta-analysis of functional neuroimaging studies

BACKGROUND

Over the past few decades, neuroimaging research in Bipolar Disorder (BD) has identified neural differences underlying cognitive and emotional processing. However, substantial clinical and methodological heterogeneity present across neuroimaging experiments potentially hinders the identification of consistent neural biomarkers of BD. This meta-analysis aims to comprehensively reassess brain activation and connectivity in BD in order to identify replicable differences that converge across and within resting-state, cognitive, and emotional neuroimaging experiments.

METHODS

Neuroimaging experiments (using fMRI, PET, or arterial spin labeling) reporting whole-brain results in adults with BD and controls published from December 1999-June 18, 2019 were identified via PubMed search. Coordinates showing significant activation and/or connectivity differences between BD participants and controls during resting-state, emotional, or cognitive tasks were extracted. Four parallel, independent meta-analyses were calculated using the revised activation likelihood estimation algorithm: all experiment types, all resting-state experiments, all cognitive experiments, and all emotional experiments. To confirm reliability of identified clusters, two different meta-analytic significance tests were employed.

RESULTS

205 published studies yielding 506 individual neuroimaging experiments (150 resting-state, 134 cognitive, 222 emotional) comprising 5745 BD and 8023 control participants were included. Five regions survived both significance tests. Individuals with BD showed functional differences in the right posterior cingulate cortex during resting-state experiments, the left amygdala during emotional experiments, including those using a mixed (positive/negative) valence manipulation, and the left superior and right inferior parietal lobules during cognitive experiments, while hyperactivating the left medial orbitofrontal cortex during cognitive experiments. Across all experiments, there was convergence in the right caudate extending to the ventral striatum, surviving only one significance test.

CONCLUSIONS

Our findings indicate reproducible localization of prefrontal, parietal, and limbic differences distinguishing BD from control participants that are condition-dependent, despite heterogeneity, and point towards a framework for identifying reproducible differences in BD that may guide diagnosis and treatment.

Relationship between baseline cognition and 18-month treatment response in bipolar disorder

BACKGROUND

To date, few studies have examined baseline cognitive function as a predictor of clinical outcome following treatment in bipolar disorder (BD). The aim of this analysis was therefore to examine the relationship between baseline cognitive function and treatment outcome in a sample of young adults with BD receiving Interpersonal Social Rhythm Therapy (IPSRT) or Specialist Supportive Care (SSC) with adjunctive pharmacotherapy.

METHODS

Eighty-six BD patients underwent baseline cognitive testing and completed 18 months of IPSRT or SCC. Univariate analyses examined the relationship between baseline cognitive function (global and individual cognitive domains) and change in mood symptom burden, and psychosocial functioning, from baseline to treatment-end.

RESULTS

Baseline global cognition was not predictive of change in mood symptom burden over 18 months of treatment. However, poorer baseline psychomotor speed performance was associated with less improvement in mood symptom burden at treatment-end. Neither baseline global cognition nor individual cognitive domain scores were associated with change in psychosocial functioning.

LIMITATIONS

Due to the exploratory nature of the study, correction was not made for multiple comparisons. Data was obtained from a relatively small sample and has been the subject of prior analysis, thereby increasing the likelihood of chance findings.

CONCLUSION

Although global cognition was not associated with outcome, when examining individual domains, poorer baseline psychomotor speed predicted less change in mood symptom burden following 18-months of psychotherapy and pharmacotherapy. This suggests that pre-treatment measures of psychomotor speed may help to identify those who require additional, and more targeted, intervention. Further large-scale research is required.

The Role of Sleep Patterns from Childhood to Adolescence in Vigilant Attention

Only a few studies addressed age-related changes from childhood to adolescence in sleep patterns, sleepiness, and attention. Vigilant attention plays a key role in cognitive performance. While its nature and course have been investigated broadly among adults, only limited research has been conducted on its development between childhood and adolescence. The main aim of the current study was to replicate previous findings about the effects of sleep loss on age-related changes in vigilance attention performance and sleepiness in a natural setting. A total of 104 children and adolescents (46 children aged 6-9 and 58 adolescents aged 13-19) wore an actigraph for a continuous five to seven nights, including weekdays and weekends. Subjective sleepiness (Karolinska Sleepiness Scale) and a Psychomotor Vigilance Test (PVT-B) were measured on two school days and one non-school day. Findings showed that PVT-B performance differed by age group, with adolescents outperforming children in PVT-B measures in spite of their elevated subjective sleepiness. Adolescents demonstrated less sleep time and increased sleepiness. Although PVT-B performance was better among adolescents, a within-subject analysis revealed that adolescents performed better on PVT measures on weekends than on weekdays. The results are discussed in relation to the synaptic elimination model.

Neuropsychological aspects of bipolar disorder

Bipolar disorder (BD) is a chronic condition with serious consequences on the health and functionality of patients who suffer from it, with a high heritability and segregation, and aprevalence of between 1% and 2%. Neuropsychological deficits have been implicated as a very important issue related to BD prognosis, so a review was conducted of these deficits, the related factors and their functional consequences. It has been determined that the presence of neuropsychological deficits can vary in patients with BD according to their mood state, with a great influence of depressive symptoms on the cognitive variability of patients with respect to the general population and differences with respect to patients in the manic phase. In euthymic patients, the most affected cognitive domains are those of memory, attention, and executive function, associated with a more severe disease, sociodemographic vulnerability factors, and stable over time. A relationship has been found between poor cognitive performance, especially executive dysfunction, and objective functional deficit. Furthermore, cognitive differences have been outlined between BD and other serious mental illnesses that are described in this review.

Inflammation, Attention, and Processing Speed in Patients With Breast Cancer Before and After Chemotherapy

BACKGROUND

Inflammation may contribute to cognitive difficulties in patients with breast cancer. We tested 2 hypotheses: inflammation is elevated in patients with breast cancer vs noncancer control participants and inflammation in patients is associated with worse attention and processing speed over the course of chemotherapy.

METHODS

Serum cytokines (interleukin [IL]-4, 6, 8, 10; tumor necrosis factor [TNF]-α) and soluble receptors [sTNFRI, II]) were measured in 519 females with breast cancer before and after chemotherapy and 338 females without cancer serving as control participants. Attention and processing speed were measured by Rapid Visual Processing (RVP), Backward Counting (BCT), and Trail Making-A (TMT-A) tests. Linear regression models examined patient vs control cytokines and receptor levels, adjusting for covariates. Linear regression models also examined relationships between patient cytokines and receptor levels and test performance, adjusting for age, body mass index, anxiety, depression, cognitive reserve, and chemotherapy duration. Statistical tests were 2-sided (α = .05).

RESULTS

sTNFRI and sTNFRII increased over time in patients relative to controls, whereas IL-4, IL-6, and IL-10 decreased. Prechemotherapy, higher IL-8 associated with worse BCT (β = 0.610, SE = 0.241, P = .01); higher IL-4 (β = -1.098, SE = 0.516, P = .03) and IL-10 (β = -0.835, SE = 0.414, P = .04) associated with better TMT-A. Postchemotherapy, higher IL-8 (β = 0.841, SE = 0.260, P = .001), sTNFRI (β = 6.638, SE = 2.208, P = .003), and sTNFRII (β = 0.913, SE = 0.455, P = .045) associated with worse BCT; higher sTNFRII also associated with worse RVP (β = -1.316, SE = 0.587, P = .03). At prechemotherapy, higher IL-4 predicted RVP improvement over time (β = 0.820, SE = 0.336, P = .02); higher sTNFRI predicted worse BCT over time (β = 5.566, SE = 2.367, P = .02). Longitudinally, increases in IL-4 associated with BCT improvement (β = -0.564, SE = 0.253, P = .03).

CONCLUSIONS

Generally, worse attention and processing speed were associated with higher inflammatory cytokines and receptors and lower anti-inflammatory cytokines in patients; future confirmatory studies are needed.

Single episode brief psychotic disorder versus bipolar disorder: A diffusion tensor imaging and executive functions study

BACKGROUND

Despite fast progress in neuroscientific approaches, the neurobiological continuum links psychotic spectrum, and affective disorder is obscure. White matter WM abnormalities found utilizing Diffusion Tensor Imaging (DTI) showing impaired communication in both disorders have been consistently demonstrated; however, direct comparisons of findings between them are scarce. This study aims to study WM abnormalities in single episode bipolar I disorder, and single episode brief psychotic disorder related to healthy control with the association of executive function.

METHODS

A cross-sectional case-control study was used to assess 60 subjects divided into 20 patients with single episode bipolar I disorder, 20 individuals with single episode brief psychotic disorder (both groups of patients were in remission), and 20 healthy controls. The present study examined the superior longitudinal fasciculus (SLF), and cingulum bundle fractional anisotropy (FA) determined from DTI images symmetrically and connected these results with cognitive functions as assessed by the trail making test (TMT) and Wisconsin card sorting test (WCST).

RESULTS

DTI data indicated that the psychotic group had a significant decrease in FA of the right SLF (p-value less than 0.001), left SLF (p-value less than 0.001), and left cingulum (p-value less than 0.001) than the bipolar I group. In terms of executive functioning, the psychotic group performed significantly worse than the bipolar I group on the TMT part B (p-value less than 0.001), the WCST (number of classifications fulfilled) (p-value less than 0.001), and perseverative errors (p-value less than 0.001).

CONCLUSION

Even after clinical remission, individuals with single episode brief psychotic disorder had more pronounced white matter impairments and executive function deficiencies than individuals with single episode bipolar I disorder.

BIPOLAR DISORDER, MOOD STABILIZERS AND COGNITIVE FLEXIBILITY: TRANSLATIONALLY DISSECTING ILLNESS FROM DRUG EFFECTS

Bipolar disorder (BD) effects on cognition are confounded by the putative cognitive impact of its major pharmacological treatments, given the neurotrophic potential of mood stabilizers, particularly lithium. We examined the area of cognitive flexibility (CF), aiming to disentangle BD from medication effects, using translational methodology. CF was assessed by CANTAB-IED (intra- extra-dimensional shift; Study 1, euthymic BD participants) and its animal analogue (Study 2, rats). Both studies included groups (1) control, (2) lithium, chronic, current treatment (LI-CHRON-C, A: >2 years, N=32; B: 2 months, N=11); (3) valproate, chronic, current treatment (VPA-CHRON-C, A: >2 years, N=30; B: 2 months, N=12). Study 2 included 2 additional groups; Group 4: LI-CHRON-PAST (2 months, stopped 1 month pretest, N=13); Group 5: LI-ACUTE (LI on test days only, N=13). In Study 1, neither total nor stage (discrimination: D; reversal R; intra- extra-dimensional shifts: IED) IED errors differed between groups [(Kruskal-Wallis: H(2, N= 94) 0.95 > p > 0.65]. Similarly in Study 2, errors did not differentiate the 5 pharmacological groups. Differences emerged only between LI-ACUTE and Controls in response latencies (D, R, IED ANOVAS: 0.002 > p > 0.0003; contrasts D, R: p = 0.002, 0.0001). In conclusion, LI and VPA BD patients were indistinguishable from Controls in IED errors, as were animals treated with LI-CHRON, current or past, or VPA-CHRON-C vs Controls. LI-ACUTE treatment produced significant latency deficits vs. Controls. Within the limitations of translational comparisons, our results suggest that the normal CF noted in euthymic BDs is not attributable to mood stabilizer effects.

Effect of Distractors on Sustained Attention and Hyperactivity in Youth With Attention Deficit Hyperactivity Disorder Using a Mobile Virtual Reality School Program

OBJECTIVE

This study examined whether distractors in virtual reality (VR) environment affected the attention and hyperactivity in children and adolescents with ADHD.

METHOD

A total of 40 students (21 ADHD, 19 controls) aged between 9 and 17 years participated in this study. A rapid visual information processing task utilizing VR (VR-RVP) was performed under two conditions (no-distractor and distractor condition). Task performance and head movement during each condition were compared, and additional analyses were conducted after grouping participants into two developmental stages.

RESULTS

Children with ADHD performed comparably to the controls under the distractor condition, but had poorer performance under the no-distractor condition. They displayed more head movement under the distractor condition than in the no-distractor condition.

CONCLUSION

VR is possibly a useful tool for investigating the effect of distractors on individuals with ADHD, and children with ADHD are more vulnerable to a low-level stimulation situation than normal children in VR.

Assessment of Attentional Processes in Patients with Anxiety-Depressive Disorders Using Virtual Reality

To characterize the attention deficits in one-hundred-fifteen participants, comprising two types of clinical profiles (affective and anxiety disorder), through a test of continuous VR execution. Method: Three tests (i.e., Nesplora Aquarium, BDI, and STAI) were used to obtain a standardized measure of attention, as well as the existence and severity of depression and anxiety, respectively. Results: Significant differences (CI = 95%) were found between the control group and the group with depression, in variables related to the speed of visual processing (p = 0.008) in the absence of distractors (p = 0.041) and during the first dual execution task (p = 0.011). For scores related to sustained attention, patients with depression and those with anxiety did not differ from controls. Our results suggest attentional deficits in both clinical populations when performing a continuous performance test that involved the participation of the central executive system of working memory.

Executive Functions Influence on Memory Process in Patients with Paranoid Schizophrenia and Bipolar Disorders with and without Psychotic Symptoms. A Pilot Study

The objective of the present study was to evaluate whether declarative memory deficits are related to executive function deficits (EF), since they could be a consequence of a poor organization of the material to memorize. This interaction between both cognitive processes can be studied simultaneously in a single task such as the Test of Memory Strategies (TSM). 23 patients with paranoid schizophrenic disorder, 11 with bipolar disorder with psychotic symptoms, 13 with bipolar disorder without psychotic symptoms and 15 healthy subjects were evaluated with the TSM; with the memory test Texts A and B (subtest of the Barcelona neuropsychological assessment battery), which assesses short-term and immediate recall without the influence of EF; and with the Trail Making Test (TMT): Part A (sustained attention) and Part B (executive control). The patients groups and the control group showed an improvement in memory performance across each of the TSM conditions. However, this facilitating effect of the strategies differed among the groups (the patients with higher EF deficits showed less improvement). Regarding these results, we conclude that this cognitive process cannot be independent of EF. However, due to the pilot nature of this study, it would be recommended to replicate these findings in new studies.

The Attentional Boost Effect in Young and Adult Euthymic Bipolar Patients and Healthy Controls

In the Attentional Boost Effect (ABE), stimuli encoded with to-be-responded targets are later recognized more accurately than stimuli encoded with to-be-ignored distractors. While this effect is robust in young adults, evidence regarding healthy older adults and clinical populations is sparse. The present study investigated whether a significant ABE is present in bipolar patients (BP), who, even in the euthymic phase, suffer from attentional deficits, and whether the effect is modulated by age. Young and adult euthymic BP and healthy controls (HC) presented with a sequence of pictures paired with target or distractor squares were asked to pay attention to the pictures and press the spacebar when a target square appeared. After a 15-min interval, their memory of the pictures was tested in a recognition task. The performance in the detection task was lower in BP than in HC, in both age groups. More importantly, neither young nor adult BP exhibited a significant ABE; for HC, a robust ABE was only found in young participants. The results suggest that the increase in the attentional demands of the detection task in BP and in adult HC draws resources away from the encoding of target-associated stimuli, resulting in elimination of the ABE. Clinical implications are discussed.

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.

Cognitive Impairment Among Tunisian Bipolar Patients: a Case-Control Study

Studies exploring the cognitive performance of bipolar patients have mainly been conducted in Western countries. To our knowledge, no surveys have been reported to date in Tunisia. The present work aimed to evaluate the cognitive functions, in the three domains of memory, attention and executive functions, among a sample of Tunisian individuals with bipolar disorder, during the remission period, compared to healthy control subjects. We found that Cognitive functions in euthymic patients with bipolar disorder were significantly more impaired than in controls, apart from the working memory that did not show a significant difference between the two groups. Our findings confirm cognitive deficits associated with bipolar disorder, even at a distance from the symptomatic phases of the disease. Thus, these anomalies may be considered as a trait marker of the disease. A better understanding of cognitive decline certainly allows for better management of psychiatric pathologies, thus improving patients' social skills and quality of life.

Neuroprogression as an Illness Trajectory in Bipolar Disorder: A Selective Review of the Current Literature

Bipolar disorder (BD) is a chronic and disabling psychiatric condition that is linked to significant disability and psychosocial impairment. Although current neuropsychological, molecular, and neuroimaging evidence support the existence of neuroprogression and its effects on the course and outcome of this condition, whether and to what extent neuroprogressive changes may impact the illness trajectory is still poorly understood. Thus, this selective review was aimed toward comprehensively and critically investigating the link between BD and neurodegeneration based on the currently available evidence. According to the most relevant findings of the present review, most of the existing neuropsychological, neuroimaging, and molecular evidence demonstrates the existence of neuroprogression, at least in a subgroup of BD patients. These studies mainly focused on the most relevant effects of neuroprogression on the course and outcome of BD. The main implications of this assumption are discussed in light of specific shortcomings/limitations, such as the inability to carry out a meta-analysis, the inclusion of studies with small sample sizes, retrospective study designs, and different longitudinal investigations at various time points.

The influence of social, psychological, and cognitive factors on the clinical course in older patients with bipolar disorder

OBJECTIVES

Research on factors that contribute to recurrence in older adults with bipolar disorder (OABD) is sparse. Previous research showed that clinical factors (e.g., age of onset, lifetime psychotic features, and suicide risk) were not associated with the recurrence in OABD. In younger adults, worse social functioning, coping style, and worse cognitive functioning are found to be associated with an unfavorable course of bipolar disorder. Therefore, this study is focusing on social, psychological, and cognitive factors in OABD. More insight in these factors is essential in order to develop and further specify preventive and treatment interventions.

METHODS

Data were used from the Dutch Older Bipolars (DOBi) cohort study. We included 64 patients for 3-year follow-up measurements, who were divided in a recurrent group and a nonrecurrent group. Logistic regression analyses were conducted to assess associations between social, psychological, and cognitive factors, and nonrecurrence.

RESULTS

39.1% reported at least one recurrence during the 3-year follow-up period. No significant associations were found between the social, psychological, and cognitive factors and having a recurrence during the follow-up period.

DISCUSSION

Participants in the recurrent group were younger, more often female and less likely to have children. Our results suggest that results from the adult bipolar disorder population cannot be extrapolated to OABD patients, underlining the need for longitudinal studies in OABD.

A Multimethod Examination of Sensitivity to Reward and Sensitivity to Punishment in Bipolar Disorder and Alcohol Dependence: Results from a 2 × 2 Factorial Design

INTRODUCTION

Shared neurobehavioral characteristics of bipolar disorder (BD) and alcohol dependence (AD), including heightened sensitivity to reward (SR), may account for high rates of BD and AD co-occurrence (BD + AD). However, empirical research is lacking. The present multimethod investigation examined SR and sensitivity to punishment (SP) among these patient groups using a reliable and well-validated self-report questionnaire of SR and SP along with a laboratory task specifically designed to distinguish SR and SP activation.

METHODS

One-hundred participants formed 4 groups: BD + AD (n = 40), BD (n = 18), AD (n = 25), and healthy controls (n = 17). Clinical interviews were administered, and participants completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSR-Q) and the Point Score Reaction Test behavioral task. Pearson correlations, hierarchical linear regression, and 2 × 2 factorial general linear modeling with Bonferroni-corrected pairwise comparisons were performed.

RESULTS

BD and AD main effects were significant on self-reported SR and SP; however, BD × AD interactions were not. BD + AD individuals were significantly higher on self-reported SR than BD and AD individuals, yet all clinical groups were similar on SP. Behavioral response times did not distinguish groups nor did they associate with self-report data.

DISCUSSION/CONCLUSION

BD and AD had additive, rather than interactive, effects on self-reported SR and SP. The methods employed, paired with their application to the present sample, may account for a lack of positive findings with behavioral data.

Assessing the validity of the Self-Report Webexec Questionnaire: Self-report vs performance neurocognitive inferences

The Webexec is a self-reported neuropsychological measure, which previous research suggests is associated with personality and executive functions. Though the Webexec could be useful for brief neuropsychological assessment, there is limited literature examining its validity. The current study's purpose was to determine Webexec's validity and association with mood symptomatology in two Historically Black College or University (HBCU) undergraduate student samples. Study 1 employed a neurocognitive battery for convergent validity testing, while the second study utilized psychological measures to determine the Webexec's association with mood-based symptomatology. Study 1 included 149 participants, with a mean age of 20.08 (SD = 1.75) years. Participants completed a demographic questionnaire, the Webexec, and a neuropsychological battery. The neuropsychological battery measured verbal fluency, visual scanning, and working memory. The Webexec was positively associated with working memory (r = 0.18, p = 0.03), but no other neuropsychological measures. Study 2 utilized an online survey with 799 HBCU participants. Results suggest Webexec was associated with depressive symptomatology (r = 0.41, p = 0.01), anxiety symptomatology (r = 0.39, p = 0.01), and impulsivity (r = 0.21, p = 0.01). Taken together, results from both studies suggest the Webexec is not consistently associated with performance measures of executive function and maybe more consistent with self-reported psychological symptoms.

White matter abnormalities and cognitive function in euthymic patients with bipolar disorder and major depressive disorder

OBJECTIVES

In recent years, a growing number of diffusion tensor imaging (DTI) studies have compared white matter integrity between patients with major depressive disorder (MDD) and bipolar disorder (BD). However, few studies have examined the pathophysiological significance of different degrees of white matter abnormalities between the two disorders. The present study comprehensively assessed white matter integrity among healthy controls (HC) and euthymic patients with MDD and BD using whole-brain tractography and examined associations between white matter integrity and cognitive functioning.

METHODS

We performed neurocognitive examinations and DTI with 30 HCs, 30 patients with MDD, and 30 patients with BD. We statistically evaluated white matter integrity and cognitive function differences across the three groups, assessing associations between white matter integrities and cognitive function.

RESULTS

The BD group showed lower fractional anisotropy (FA) for the corpus callosum body, as well as lower, sustained attention and set-shifting scores compared to the other groups. FA for the left body of the corpus callosum was correlated with sustained attention in patients with BD.

CONCLUSIONS

The significant reduction of white matter integrity in the corpus callosum in BD, compared to MDD, was associated with an impairment of sustained attention. This result promotes the understanding of the significance of white matter integrity in mood disorders.

Default mode network activity in bipolar disorder

Since its discovery in 1997, the default mode network (DMN) and its components have been extensively studied in both healthy individuals and psychiatric patients. Several studies have investigated possible DMN alterations in specific mental conditions such as bipolar disorder (BD). In this review, we describe current evidence from resting-state functional magnetic resonance imaging studies with the aim to understand possible changes in the functioning of the DMN in BD. Overall, several types of analyses including seed-based and independent component have been conducted on heterogeneous groups of patients highlighting different results. Despite the differences, findings seem to indicate that BD is associated with alterations in both frontal and posterior DMN structures, mainly in the prefrontal, posterior cingulate and inferior parietal cortices. We conclude this review by suggesting possible future research directions.

Exercise is medicine: a new perspective for health promotion in bipolar disorder

INTRODUCTION

Similar effects in reducing the symptoms of the mood disorder are reported in the literature compared the action of drugs and aerobic exercise sessions, demonstrating the potential of exercise in the control and mood stabilization. Therefore, there are many reasons to believe that the increased cardiorespiratory fitness (VO_2max) can be an important means of protection and a reducing potential of physical and mental damage in bipolar disorders (BD). This review will highlight the current pattern of response of exercise on the pathophysiology of BD, relating the possible mechanisms, and hypotheses based on exercises.

AREAS COVERED

The mechanism of monoaminergic action and its relationship with exercise, role of physical conditioning and increased VO_2Max on neurotrophin release, and new perspectives on long-term exercise will be reviewed.

EXPERT OPINION

The adaptations to training, although little explored in the context of BD, can induce the expression of substances that co-regulate several processes related to the pathophysiology of BD. Furthermore, high intensity interval training (HIIT) can also be adjusted to improve the physical fitness and health in patients with BD. Future research is needed to adopt a training strategy that is both time efficient and adequate for the population in question.

Predictive factors of functional outcome in patients with bipolar I disorder: a five-year follow-up

BACKGROUND

Functional impairment is commonly encountered among patients with bipolar disorder (BD) during periods of remission. The distribution of the impairment of the functional outcome is heterogeneous. The objective of this current investigation was to identify neurocognitive and clinical predictors of psychosocial functioning in a sample of patients with BD.

METHODS

Seventy-six patients (59.2% females) and 40 healthy controls (50% females), aged 18 to 55 years, were assessed using a comprehensive neurocognitive battery (six neurocognitive domains), and the Functioning Assessment Short Test (FAST), at baseline and after a 5-year follow-up. Stepwise regression models were used to identify predictor variables related to psychosocial functioning.

RESULTS

The number of hospitalizations during the follow-up, the change occurred in the neurocognitive composite index (NCI change), and NCI at baseline explained 30.8% of the variance of functioning. The number of hospitalizations during the follow-up was the variable that explained a greater percentage of the variance (16.9%). Verbal memory at baseline and the change in sustained attention during the follow-up explained 10% and 5.9% of the variance of the psychosocial functioning, respectively.

LIMITATIONS

The interval of 5 years between the two assessments could be too short to detect a possible progression in functional outcome for the overall sample.

CONCLUSIONS

The clinical course during the follow-up is the factor that has a greater impact on psychosocial functioning in patients with BD. Thus, the interventions aimed to promote prevention of relapses should be considered as essential for avoiding functional impairment in these patients.

Prefrontal cortical activation during working memory task anticipation contributes to discrimination between bipolar and unipolar depression

Distinguishing bipolar disorder (BD) from major depressive disorder (MDD) is clinically challenging, especially during depressive episodes. While both groups are characterized by aberrant working memory and anticipatory processing, the role of these processes in discriminating BD from MDD remains unexplored. In this study, we examine how brain activation corresponding to anticipation of and performance on easy vs. difficult working memory tasks with emotional stimuli contributes to discrimination among BD, MDD, and healthy controls (HC). Depressed individuals with BD (n = 18), MDD (n = 23), and HC (n = 23) were scanned while performing a working memory task in which they had to first anticipate performance on 1-back (easy) or 2-back (difficult) tasks with happy, fearful, or neutral faces, and then, perform the task. Anticipation-related and task-related brain activation was measured in the whole brain using functional magnetic resonance imagining. We used an elastic-net regression for variable selection, and a random forest classifier for BD vs. MDD classification. The former selected the activation differences (1-back minus 2-back) in the lateral and medial prefrontal cortices (PFC) during task anticipation and performance on the working memory tasks with fearful and neutral faces as variables relevant for BD vs. MDD classification. BD vs. MDD were classified with 70.7% accuracy (p < 0.01) based on the neuroimaging measures alone, with 80.5% accuracy (p = 0.001) based on clinical measures alone, and with 85.4% accuracy (p < 0.001) based on clinical and neuroimaging measures together. These findings suggest that PFC activation during working memory task anticipation and performance may be an important biological marker distinguishing BD from MDD.

How to improve clinical practice on involuntary hospital admissions of psychiatric patients: Suggestions from the EUNOMIA study

Number and procedures of involuntary hospital admissions vary in Europe according to the different socio-cultural contexts. The European Commission has funded the EUNOMIA study in 12 European countries in order to develop European recommendations for good clinical practice in involuntary hospital admissions. The recommendations have been developed with the direct and active involvement of national leaders and key professionals, who worked out national recommendations, subsequently summarized into a European document, through the use of specific categories. The need for standardizing the involuntary hospital admission has been highlighted by all centers. In the final recommendations, it has been stressed the need to: providing information to patients about the reasons for hospitalization and its presumable duration; protecting patients’ rights during hospitalization; encouraging the involvement of family members; improving the communication between community and hospital teams; organizing meetings, seminars and focus-groups with users; developing training courses for involved professionals on the management of aggressive behaviors, clinical aspects of major mental disorders, the legal and administrative aspects of involuntary hospital admissions, on communication skills. The results showed the huge variation of involuntary hospital admissions in Europe and the importance of developing guidelines on this procedure.

Manipulation ability of internal representation in patients with euthymic bipolar I disorder and schizophrenia using a mental rotation task

BACKGROUND

A growing body of literature has suggested that effective emotion regulation is influenced by cognitive function. Maintenance and manipulation of internal representations occur in working memory (WM), and impairments of WM have been reported in patients with bipolar disorder.

METHODS

We examined the manipulation ability of internal representations in WM using mental rotation (MR) tasks, and compared the task performances of euthymic bipolar I disorder patients to those of schizophrenia patients and healthy controls. In this study, 20 euthymic bipolar I disorder patients, 20 schizophrenia patients, and 38 healthy controls were recruited. People and letter MR tasks were employed to evaluate the ability of WM manipulation.

RESULTS

Compared to healthy controls, euthymic bipolar I disorder patients showed substantially higher error rates of people MR task and slower responses in both people and letter MR tasks. Schizophrenia patients showed no difference in error rate and response time in MR tasks compared to healthy controls; however, they showed significantly slower responses in people MR task compared to controls. MR task performance was not different between euthymic bipolar and schizophrenia patients.

CONCLUSION

Our study results indicate that manipulation of internal representation, especially in the egocentric MR, is impaired in bipolar disorder even in the emotionally-stable state. We speculate that impaired imagery manipulation might be related to alterations in empathic ability, susceptibility of mental imagery, and emotion regulation strategies observed in bipolar disorder.

Elated or sad mood induction affects the attention of patients with a bipolar disorder less than that of patients with a depressive disorder

Introduction: The role of acute mood states as mediating factors in cognitive impairment in patients with mania or depression is not sufficiently clear. Similarly, the extent to which cognitive impairment is trait or state-specific remains an open question. Therefore, the aim of this study was to investigate the effect of a mood-induction on attention in patients with an affective disorder.Methods: Twenty-two depressed bipolar patients, 10 manic bipolar patients, 17 with a depressive episode (MDE), and 24 healthy controls performed the Attention-Network-Test (ANT). In a within-participants design, elated and sad moods were induced by an autobiographic recall and measured on a self-report scale. Subsequently, participants performed the ANT again.Results: The modulating effect of the elated mood induction on attention was small. Only the MDE group displayed moderate improvements in selective attention and tonic alertness. Surprisingly, after the sad mood induction, patients with MDE improved moderately on phasic and tonic alertness. Phasic alertness was also enhanced in patients with mania. Finally, after the mood induction, patients with MDE showed the largest variability in attentional performance.Conclusions: Results showed only small effects of mood induction on attention. This supports the view that attention deficits reflect trait variables.

Affective cognition in bipolar disorder: A systematic review by the ISBD targeting cognition task force

BACKGROUND

Impairments in affective cognition are part of the neurocognitive profile and possible treatment targets in bipolar disorder (BD), but the findings are heterogeneous. The International Society of Bipolar Disorder (ISBD) Targeting Cognition Task Force conducted a systematic review to (i) identify the most consistent findings in affective cognition in BD, and (ii) provide suggestions for affective cognitive domains for future study and meta-analyses.

METHODS

The review included original studies reporting behavioral measures of affective cognition in BD patients vs controls following the procedures of the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement. Searches were conducted on PubMed/MEDLINE, EMBASE, and PsychInfo from inception until November 2018.

RESULTS

A total of 106 articles were included (of which nine included data for several affective domains); 41 studies assessed emotional face processing; 23 studies investigated reactivity to emotional words and images; 3 investigated explicit emotion regulation; 17 assessed implicit emotion regulation; 31 assessed reward processing and affective decision making. In general, findings were inconsistent. The most consistent findings were trait-related difficulties in facial emotion recognition and implicit emotion regulation, and impairments in reward processing and affective decision making during mood episodes. Studies using eye-tracking and facial emotion analysis revealed subtle trait-related abnormalities in emotional reactivity.

CONCLUSION

The ISBD Task Force recommends facial expression recognition, implicit emotion regulation, and reward processing as domains for future research and meta-analyses. An important step to aid comparability between studies in the field would be to reach consensus on an affective cognition test battery for BD.

Neurocognitive Predictors of Clinical Improvement in Selective Serotonin Reuptake Inhibitor-Treated Adolescents with Major Depressive Disorder

OBJECTIVES

Numerous studies have suggested cognitive deficits as consistently associated with adolescent depression. No study to date, however, has assessed neurocognitive predictors of selective serotonin reuptake inhibitor (SSRI) treatment response in adolescents with depression. This study examined neurocognitive tasks at baseline as predictors of clinical improvement with SSRI treatment (fluoxetine) at week 6 and 12 in an adolescent population.

METHODS

Adolescents with depression were recruited from a child and adolescent psychiatry outpatient clinic at a university medical center. Twenty-four adolescents (mean age 14.8 years) with Major Depressive Disorder completed tasks of the Cambridge Neuropsychological Test Automated Battery, including visual memory, executive functioning, sustained attention, and impulsivity. Depression severity, measured by the Children's Depression Rating Scale-Revised (CDRS-R), was assessed at week 6 and 12 and clinical improvement was defined as percentage (%) change in CDRS-R from baseline.

RESULTS

Clinical improvement is noted at both week 6 (mean % change in CDRS-R [M] = 46.8, standard deviation [SD] = 51.9) and week 12 (M = 87.9, SD = 57.2). Results reveal that less difficulty in sustained attention (p = 0.02), lower impulsivity (p = 0.00), and better planning (p = 0.04) at baseline were predictors of greater clinical improvement at week 6. Lower impulsivity at baseline remained significantly predictive of clinical improvement at week 12 (p = 0.01).

CONCLUSION

Neurocognitive assessments could potentially help identify a subset of depressed adolescents who may not respond to conventional SSRI treatment and who may be better candidates for alternative or augmentation treatments.

Association of subthreshold manic symptoms and cognitive impairments in euthymic patients with bipolar disorder I

Cognitive impairments exist during the euthymic period of bipolar disorder (BD). However, the impact of clinical factors (e.g., subthreshold symptoms and body mass index) on cognitive function in euthymic patients with bipolar disorder I is inconsistent. This cross-sectional study included 83 patients with euthymic BD I and 115 healthy controls. The Repeatable Battery for the Assessment of Neuropsychological Status indices were used to assess cognitive function. We assessed the relationship between cognitive function and clinical impact factors. Performance in language abilities, attention, and immediate memory was worse in euthymic BD I. Spearman's correlation revealed that indices for immediate memory and attention were negatively correlated with subthreshold manic symptoms, and indices for delayed memory were positively correlated with years of education. Linear regressions indicated that subthreshold manic symptoms were the best predictors of immediate memory and attention. Years of education predicted performance in most cognitive domains, except immediate memory. Individuals with euthymic BD I exhibited cognitive deficits in language learning, attention, and immediate memory. Our study highlights the importance of the effect of subthreshold manic symptoms on cognitive function in remitted BD; these symptoms should receive more attention and be targeted in personalized clinical therapeutic interventions.

Neurocognitive profile of patients with Bipolar Affective Disorder in the euthymic phase

Bipolar disorder is a chronic psychiatric condition characterized by episodes of elevated/irritable and depressed moods resulting in the loss of more disability-adjusted life years (DALYs) than other major conditions. The neurocognitive impairments in these patients interfere with sustained goal-directed performance and achievement even during the euthymic phase of the illness.

METHODOLOGY

The study aimed to explore the neurocognitive profile of patients in their euthymic phase. We matched 30 patients diagnosed with Bipolar Affective Disorder (BD) in the age range of 20-40 years with 30 healthy controls (with no axis I or II diagnosis, assessed on MINI) matched on age, gender, and education. The neurocognitive profile was assessed using NIMHANS Neuropsychology Battery.

RESULTS

Euthymic phase patients with bipolar disorder had statistically significant low scores on the speed of processing information as compared to healthy controls. Although impaired in BD group, no statistically significant difference was found between the two groups on executive functions and memory.

CONCLUSION

The findings of the study suggest that cognitive retraining aimed at ameliorating these deficits can be a used as an essential intervention in rehabilitation programs to successfully reintegrate patients with the bipolar affective disorder into the society. The research also indicates that despite the symptomatic recovery between the episodes, impairments in the speed of processing information continue to disrupt performance in patients with Bipolar Disorder.

Dynamic sustained attention markers differentiate atypical development: The case of Williams syndrome and Down's syndrome

Impaired sustained attention is considered an important factor in determining poor functional outcomes across multiple cognitive and behavioural disorders. Sustained attention is compromised for both children with Williams syndrome (WS) and Down's syndrome (DS), but specific difficulties remain poorly understood because of limitations in how sustained attention has been assessed thus far.

In the current study, we compared the performance of typically developing children (N = 99), children with WS (N = 25), and children with DS (N = 18), on a Continuous Performance Task – a standard tool for measuring sustained attention. In contrast to previous studies, primarily focused on overall differences in mean performance, we estimated the extent to which performance changed over time on task, thus focusing directly on the sustained element of performance. Children with WS and children with DS performed more poorly overall compared to typically developing children. Importantly, measures specific to changes over time differentiated between children with the two syndromes. Children with WS showed a decrement in performance, whereas children with Down's syndrome demonstrated non-specific poor performance. In addition, our measure of change in performance predicted teacher-rated attention deficits symptoms across the full sample.

An approach that captures dynamic changes in performance over assessments may be fruitful for investigating similarities and differences in sustained attention for other atypically developing populations.

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Impaired sustained attention is a key factor in determining poor functional outcomes.

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Children with WS or DS performed more poorly overall than neurotypical children.

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In addition, children with WS showed a decrement in performance over time.

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In contrast, children with DS demonstrated non-specific poor performance.

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Our dynamic sustained attention measure predicted teacher-rated attention symptoms.

Trauma-related psychiatric and behavioral conditions are uniquely associated with sustained attention dysfunction

OBJECTIVE

It is increasingly recognized that trauma victims, particularly Veterans, have co-occurring psychological and physical conditions that impact cognition, especially the domains of sustained attention and executive functioning. Although previous work has generally attempted to isolate the unique cognitive effects of common combat-related comorbidities, less work has been done to examine how these conditions co-occur, and whether unique cognitive signatures accompany certain clinical combinations.

METHOD

To address this gap, we examined how several deployment-related conditions were associated with performance on a well-validated measure of sustained attention (i.e., gradual onset continuous performance task [gradCPT]) and a battery of standard neuropsychological measures in 123 Veterans from the Translational Research Center for TBI and Stress Disorders. Initially, a Principal component analysis was conducted to investigate how comorbid conditions grouped together.

RESULTS

Several sustained attention measures from the gradCPT were differentially associated with four unique combinations of trauma-related pathology. Specifically, a somatic component representing the combination of current pain, sleep disturbance, and mild traumatic brain injury was associated with a higher rate of failures of attentional engagement. On the other hand, a comorbid posttraumatic stress disorder (PTSD) and mood disorder component (moodPTSD), as well as a substance use disorder component, were associated with higher rates of inhibitory control failures. Increased attentional instability was associated with moodPTSD as well as an anxiety disorder component. In contrast, the cognitive effects of deployment-related trauma were not observed on standard neuropsychological measures.

CONCLUSION

These findings suggest that unique combinations of trauma-related pathology have dissociable effects on sustained attentional control. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Emotional asymmetries in refractory medial temporal and frontal lobe epilepsy: Their impact on predicting lateralization and localization of seizures

BACKGROUND

Emotional disturbances have been reported in patients with epilepsy. Although conflicting results emanate from relevant studies, depressive symptoms are seen more often in temporal lobe epilepsy (TLE) whereas, hypomanic/manic symptoms usually accompany frontal lobe epilepsy (FLE); the above psychiatric symptoms are especially seen in refractory epilepsy. However, neocortical TLE and medial TLE are considered as distinct epileptic syndromes, and there is limited literature on comparison of affective traits in medial TLE (MTLE) and FLE.

AIM

In the present study, we sought to investigate affective traits among epilepsy surgery candidates suffering refractory left medial TLE (LMTLE), right medial TLE (RMTLE), left FLE (LFLE), and right FLE (RFLE).

RESULTS

Our results revealed that patients with MTLE scored significantly higher than the ones with FLE in depression, anxiety, asthenia, and melancholia as measured by the Symptoms Rating Scale for Depression and Anxiety (SRSDA), while patients with FLE scored significantly higher in mania than those with MTLE. Moreover, patients with MTLE scored significantly higher than their FLE counterparts on the anxiety scale of the State Trait Personality Inventory (STPI)-trait version. When laterality of the seizure focus was taken into account, no differences were found among both patients with MTLE and patients with FLE, with exception for the Trail Making Test part B (TMT-B) in which patients with RMTLE performed significantly worse than patients with LMTLE. Seizure frequency was higher for FLE.

CONCLUSIONS

We provide evidence for an anterior-frontal versus a posterior-medial temporal cerebral functional asymmetry with regard to the manifestation of manic and depressive emotional traits in FLE and MTLE, respectively. Our results are mainly discussed within the frame of their contribution in localizing and to a lesser extent in lateralizing seizures foci in epilepsy surgery candidates. We suggest that this is of great importance in the context of preoperative monitoring of epilepsy surgery, especially when neuropsychologists are called upon to provide anatomical information in defining the functional deficit zone.

Differential effects of unipolar versus bipolar depression on episodic memory updating

Episodic memories, when reactivated, can be modified or updated by new learning. Since such dynamic memory processes remain largely unexplored in psychiatric disorders, we examined the impact of depression on episodic memory updating. Unipolar and bipolar depression patients, and age/education matched controls, first learned a set of objects (List-1). Two days later, participants in all three groups were either reminded of the first learning session or not followed by the learning of a new set of objects (List-2). Forty-eight hours later, List-1 recall was impaired in unipolar and bipolar patients compared to control participants. Further, as expected, control participants who received a reminder spontaneously recalled items from List-2 during recall of List-1, indicative of an updated List-1 memory. Such spontaneous intrusions were also seen in the unipolar and bipolar patients that received the reminder, suggesting that memory updating was unaffected in these two patient groups despite impaired recall of List 1. Unexpectedly, we observed a trend towards higher intrusions, albeit statistically insignificant, not only in the reminder but also in the no-reminder subgroups of bipolar patients. We probed this further in a second cohort by testing recall of List-2, which was also impaired in both depression groups. Again bipolar patients showed intrusions, but this time in the reverse order from List-1 into List-2, independent of a reminder. Taken together, despite impaired recall, updating of episodic memories was intact and unidirectional in unipolar depression. In contrast, indiscriminate updating, as evidenced by bidirectional interference between episodic memories, was seen in bipolar depression. These findings reveal a novel distinction between unipolar versus bipolar depression using a reactivation-dependent memory updating paradigm.

Attentional engagement increases inferior frontal gyrus activity and mutes limbic activity in pediatric bipolar disorder: Meta-analyses of fMRI studies

OBJECTIVES

Attention deficit has been shown to exist in adult and pediatric bipolar disorder across the life span. Given that emotion dysregulation is central to bipolar disorder, this study hypothesizes that emotional circuitry regions are altered along with anomalies in the attentional systems during cognitive deployment in bipolar disorder.

METHODS

An activation likelihood estimation meta-analysis of attentional activities using GingerALE software was completed for adult and pediatric bipolar disorder populations in all published studies till December 2017. The meta-analysis of all fMRI studies included a total of ten pediatric studies (comprised of pediatric bipolar disorder (PBD) and typically developing (TD) groups) and nine adult patient studies (comprised of adult bipolar disorder (ABD) and healthy control (HC) groups).

RESULTS

While engaged in attentional tasks, increased activation was seen in inferior frontal gyrus with decreased activation in limbic regions in subjects with PBD, relative to TD. Differential patterns of underactivity were also noted in the dorsal attentional system i.e., frontostriatal circuit (dorsolateral prefrontal cortex, anterior cingulate cortex, right lentiform nucleus and right globus pallidus) in PBD patients relative to the TD. However, we did not see any significant differences between the adult groups i.e., ABD vs. HC.

CONCLUSIONS

In PBD, deploying attentional system potentially improves the fronto-limbic affective circuitry function, despite impaired dorsal attentional system i.e., fronto-striatal circuitry. In contrast, these neural correlates underlying attentional engagement appeared to be not significant in adult BD.

LIMITATIONS

We examined the PBD vs. TD and the ABD vs. HC separately instead of four-way contrast (dual meta-analytic study). Also, attentional tasks were not unidimensional and tend to capture selective and sustained attention along with response inhibition, thereby recruiting multiple brain circuits.

Individual differences in sustained attention are associated with cortical thickness

Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta-analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention performance. Sustained attention was measured using the gradual onset continuous performance task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high-resolution structural MRI scans. Whole-brain vertex-wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network-based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.

High-frequency repetitive transcranial magnetic stimulation (rTMS) improves neurocognitive function in bipolar disorder

BACKGROUND

Patients with bipolar disorder (BD) present widespread and significant neurocognitive impairments during all stages of the disorder. Repetitive transcranial magnetic stimulation (rTMS) has been used to improve clinical outcomes in common psychiatric diseases, such as depression, anxiety disorders, schizophrenia, and BD. Whether rTMS can improve cognitive function in BD patients remains unclear. The present study explored the regulatory effects of rTMS on cognitive function in patients with BD.

METHODS

Fifty-two eligible subjects with BD were randomly assigned to receive active or sham rTMS via high-speed magnetic stimulator with a figure-of-eight coil for 10 consecutive days. In the active rTMS group, a total of 25,000 stimuli were applied over the left dorsolateral prefrontal cortex at 110% of the motor threshold. The sham group received corresponding sham stimulation. Clinical manifestations and cognitive functions were assessed using a modified 24-item Hamilton Depression Rating Scale (HDRS), the Young Mania Rating Scale (YMRS), and the MATRICS Consensus Cognitive Battery (MCCB).

RESULTS

Ten consecutive days of high-frequency active rTMS improved scores on the Wechsler Memory Scale-III Spatial Span, and the MCCB Category Fluency subtest, without intolerable adverse effects. No significant differences in HDRS or YMRS scores were found between groups.

LIMITATIONS

No follow-up after the intervention. The effect of the drug on cognitive function in subjects was not excluded.

CONCLUSIONS

Short-term rTMS can improve cognitive function in BD patients.

CHRM2 Genotype Affects Inhibitory Control Mechanisms During Cognitive Flexibility

The cholinergic system is one of the most important neurotransmitter systems, but knowledge about the relevance of the cholinergic muscarinergic receptor system for cognitive functions is still scarce. Evidence suggests that the cholinergic muscarinic 2 receptor (CHRM2) plays an important role in the processing of cueing/prior information that help to increase the efficacy of lower-level attentional processes. In the current study, we investigated whether this is also the case for higher-level cognitive flexibility mechanisms. To this end, we tested N = 210 healthy adults with a backward inhibition task, in which prior information needs to be used to guide cognitive flexibility mechanisms. Testing different polymorphisms of the CHRM2 gene, we found that variation in this gene play a role in cognitive flexibility. It could be demonstrated that rs8191992 TT genotype carriers are better able to suppress no longer relevant information and to use prior information for cognitive flexibility, compared to A allele carriers. We further found that rs2350780 GG genotype carriers performed worse than A allele carriers. The results broaden the relevance of the CHRM2 system for cognitive functions beyond attentional selection processes. Corroborating recent theories on the relevance of the cholinergic system for cognitive processes, these results suggest that CHRM2 is important to process of "prior information" needed to inform subsequent cognitive operations. Considering the importance of prior information for adaptive behavioral control, it is possible that CHRM2 also modulates other instances of higher-level cognitive processes as long as these require the processing of "prior information."

Neurocognitive Endophenotypes of Schizophrenia and Bipolar Disorder and Possible Associations with FKBP Variant rs3800373

Introduction

Schizophrenia(SCZ) and Bipolar disorder (BD) are frequently occurring and impairing disorders that affect around 1% of the population. Important endophenotypes in the genetic research of SCZ and BD are cognitive functions. Core symptoms for SCZ and BD are impairments in working memory, declarative memory and attention, all of which fulfill the criteria for an endophenotype. The FK506 Binding Protein 5 (FKBP5) gene codes for a co-chaperone of the glucocorticoid receptor and has been reported to be associated with cognition.

Aim

The aims of our research were to determine the degree of cognitive impairment in patients suffering from SCZ and BD and to explore the association of the FKBP5 variant rs3800373 genotype with the cognitive endophenotypes.

Material and Methods

Patients and healthy controls were recruited over a period of two years from the Psychiatric Clinic, Clinical Center University of Sarajevo. Genotyping and neuropsychological assessments were performed for 263 subjects (129 SCZ, 53 BD, and 81 healthy controls [HC]). Neuropsychological assessments were performed for all patients with the Trail Making Test-A&B (TMT-A&B) and Digit-span forward&backwards tasks. The single nucleotide polymorphism (SNP) rs3800373 in the FKBP5 gene was genotyped using Infinium PsychArray Bead Chips.

Results and Conclusion

SCZ and BD patients performed lower than HC in the TMT-A&B and in the Digit-span backwards task, while no differences were observed between SCZ and BD patients. While SCZ patients performed lower than HC in the Digit-span forwards task, there were no differences between BD and HC or between BD and SCZ. Rs 3800373 was not associated with performance in the TMT-A&B or Digit-span forwards&backwards tasks. SCZ and BD share largely overlapping neurocognitive characteristics. Rs3800373 was not associated with performance in the neuropsychological tests. However, given the limited sample size, the results do not exclude an association with the rs3800373 variant in a larger sample. Furthermore, as the analysis was limited to one SNP, the results cannot be generalized to other genetic variants in FKBP5.

The relationship between cognitive and social functioning in older patients with bipolar disorder

OBJECTIVES

Patients with bipolar disorder (BD) show specific cognitive impairments, especially in the domains of attention, executive functioning and memory. Social and occupational problems seem to exist in 30-60% of BD patients. This study analysed the relationship between cognitive and social functioning in older age BD (OABD) patients.

METHODS

This study included 63 OABD patients (aged > 60). Cognitive functioning was measured by an extensive neuropsychological assessment including global cognitive functioning, attention, learning and memory, executive functioning and verbal fluency. Social functioning, was obtained by clinical interview, including global social functioning, meaningful contacts and social participation. Linear regression analyses were conducted between cognitive performance and social functioning and the role of depression severity and disease duration was explored.

RESULTS

Global social functioning, number of meaningful contacts and social participation were not interrelated. Global cognitive functioning, learning and memory and executive functioning were positively associated with global social functioning. No associations were found between cognitive functioning and social participation or meaningful contacts. Depression severity and disease duration were no effect modifiers.

LIMITATIONS

Limitations include the use of a sample with relatively low cognitive and social impairments and the use of a cross-sectional research design.

CONCLUSIONS

Global social functioning judged by the clinician was found to be independent of social functioning defined by the number of social contacts and social participation as reported by the patient. Global social functioning was related to cognitive functioning. An integrative treatment intervention including cognitive training and addressing social functioning may improve daily functioning in OABD patients.

An Initial Examination of Performance on Two Versions of the Iowa Gambling Task

Objective

To examine differences between two versions of the Iowa Gambling Task (IGT).

Method

A total of 282 undergraduate students completed one of two versions of the IGT: the original version from 1994 (n = 132), or the 2007 version available through Psychological Assessment Resources (PAR) (n = 150).

Results

PAR (2007 version) IGT participants decided more advantageously (i.e., selected more from the small immediate reward but long-term positive/gain decks than the large immediate reward but long-term negative/loss decks) than original IGT participants during Trials 21-60. This difference was likely due to fewer Deck B selections by the PAR IGT participants during the early (Trials 1-40) and later (Trials 41-100) trials.

Conclusions

The PAR IGT may result in a greater ability to make future-oriented, advantageous decisions more quickly than on the original IGT. Implications for future assessment of decision-making impairments in clinical and research settings are discussed.

Dynamic ErbB4 Activity in Hippocampal-Prefrontal Synchrony and Top-Down Attention in Rodents

Top-down attention is crucial for meaningful behaviors and impaired in various mental disorders. However, its underpinning regulatory mechanisms are poorly understood. We demonstrate that the hippocampal-prefrontal synchrony associates with levels of top-down attention. Both attention and synchrony are reduced in mutant mice of ErbB4, a receptor of neuregulin-1. We used chemical genetic and optogenetic approaches to inactivate ErbB4 kinase and ErbB4+ interneurons, respectively, both of which reduce gamma-aminobutyric acid (GABA) activity. Such inhibitions in the hippocampus impair both hippocampal-prefrontal synchrony and top-down attention, whereas those in the prefrontal cortex alter attention, but not synchrony. These observations identify a role of ErbB4-dependent GABA activity in the hippocampus in synchronizing the hippocampal-prefrontal pathway and demonstrate that acute, dynamic ErbB4 signaling is required to command top-down attention. Because both neuregulin-1 and ErbB4 are susceptibility genes of schizophrenia and major depression, our study contributes to a better understanding of these disorders. VIDEO ABSTRACT.

Theta Oscillations Organize Spiking Activity in Higher-Order Visual Thalamus during Sustained Attention

Higher-order visual thalamus plays a fundamental but poorly understood role in attention-demanding tasks. To investigate how neuronal dynamics in higher-order visual thalamus are modulated by sustained attention, we performed multichannel electrophysiological recordings in the lateral posterior-pulvinar complex (LP/pulvinar) in the ferret (Mustela putorius furo). We recorded single unit activity and local field potential (LFP) during the performance of the five-choice serial reaction time task (5-CSRTT), which is used in both humans and animals as an assay of sustained attention. We found that half of the units exhibited an increasing firing rate during the delay period before stimulus onset (attention-modulated units). In contrast, the non-attention-modulated units responded to the stimulus, but not during the delay period. Spike-field coherence (SFC) of only the attention-modulated neurons significantly increased from the start of the delay period until screen touch, predominantly in the θ frequency band. In addition, θ power and θ/γ phase amplitude coupling (PAC) were elevated throughout the delay period. Our findings suggest that the θ oscillation plays a central role in orchestrating thalamic signaling during sustained attention.

The Effects of Martial Arts Training on Attentional Networks in Typical Adults

There is substantial evidence that training in Martial Arts is associated with improvements in cognitive function in children; but little has been studied in healthy adults. Here, we studied the impact of extensive training in Martial Arts on cognitive control in adults. To do so, we used the Attention Network Test (ANT) to test two different groups of participants: with at least 2 years of Martial Arts experience, and with no experience with the sport. Participants were screened from a wider sample of over 500 participants who volunteered to participate. 48 participants were selected: 21 in the Martial Arts group (mean age = 19.68) and 27 in the Non-Martial Arts group (mean age = 19.63). The two groups were matched on a number of demographic variables that included Age and BMI, following the results of a previous pilot study where these factors were found to significantly impact the ANT measures. An effect of Martial Arts experience was found on the Alert network, but not the Orienting or Executive ones. More specifically, Martial Artists showed improved performance when alert had to be sustained endogenously, performing more like the control group when an exogenous cue was provided. This result was further confirmed by a negative correlation between number of years of Martial Arts experience and the costs due to the lack of an exogenous cue suggesting that the longer a person takes part in the sport, the better their endogenous alert is. Results are interpreted in the context of the impact of training a particular attentional state in specific neurocognitive pathways.

Tracking behavioral and neural fluctuations during sustained attention: A robust replication and extension

Novel paradigms have allowed for more precise measurements of sustained attention ability and fluctuations in sustained attention over time, as well as the neural basis of fluctuations and lapses in performance. However, in recent years, concerns have arisen over the replicability of neuroimaging studies and psychology more broadly, particularly given the typically small sample sizes. One recently developed paradigm, the gradual-onset continuous performance task (gradCPT) has been validated behaviorally in large samples of participants. Yet neuroimaging studies investigating the neural basis of performance on this task have only been collected in small samples. The present study completed both a robust replication of the original neuroimaging findings and extended previous results from the gradCPT task using a large sample of 140 Veteran participants. Results replicate findings that fluctuations in attentional stability are tracked over time by BOLD activity in task positive (e.g., dorsal and ventral attention networks) and task negative (e.g., default network) regions. Extending prior results, we relate this coupling between attentional stability and on-going brain activity to overall sustained attention ability and demonstrate that this coupling strength, along with across-network coupling, could be used to predict individual differences in performance. Additionally, the results extend previous findings by demonstrating that temporal dynamics across the default and dorsal attention networks are associated with lapse-likelihood on subsequent trials. This study demonstrates the reliability of the gradCPT, and underscores the utility of this paradigm in understanding attentional fluctuations, as well as individual variation and deficits in sustained attention.

Neural systems underlying affective disorders

Three main approaches are used to explore the neural correlates of mood disorder: neuropsychological studies, neuroimaging studies and post-mortem investigations. Lesion studies implicate disturbances in the frontal lobe, basal ganglia, striatum and anterior temporal cortex. Early neurocognitive and neuropathological investigations led to a ‘hypofrontality’ hypothesis of unipolar and bipolar depression, but functional neuroimaging has revealed a more complex picture. Thus, increased metabolism may occur in the subgenual anterior cingulate gyrus in resting-state studies of depression and sad-mood induction. Antidepressants may reduce this activity. Amygdala hyperactivation also is associated with affective disorders. Task-related studies reveal abnormal biases in memory, the experience of pleasure and the perception of emotional facial expressions. There is still little clarity whether the abnormalities in brain activation represent state or trait characteristics of affective disorders.