Processing In Bipolar Disorder Research Articles

Auditory-prosodic processing in bipolar disorder; from sensory perception to emotion

ObjectivesAccurate emotion processing is critical to understanding the social world. Despite growing evidence of facial emotion processing impairments in patients with bipolar disorder (BD), comprehensive investigations of emotional prosodic processing is limited. The existing (albeit sparse) literature is inconsistent at best, and confounded by failures to control for the effects of gender or low level sensory-perceptual impairments. The present study sought to address this paucity of research by utilizing a novel behavioural battery to comprehensively investigate the auditory-prosodic profile of BD. MethodsFifty BD patients and 52 healthy controls completed tasks assessing emotional and linguistic prosody, and sensitivity for discriminating tones that deviate in amplitude, duration and pitch. ResultsBD patients were less sensitive than their control counterparts in discriminating amplitude and durational cues but not pitch cues or linguistic prosody. They also demonstrated impaired ability to recognize happy intonations; although this was specific to male's with the disorder. The recognition of happy in the patient group was correlated with pitch and amplitude sensitivity in female patients only. LimitationsThe small sample size of patients after stratification by current mood state prevented us from conducting subgroup comparisons between symptomatic, euthymic and control participants to explicitly examine the effects of mood. ConclusionsOur findings indicate the existence of a female advantage for the processing of emotional prosody in BD, specifically for the processing of happy. Although male BD patients were impaired in their ability to recognize happy prosody, this was unrelated to reduced tone discrimination sensitivity. This study indicates the importance of examining both gender and low order sensory perceptual capacity when examining emotional prosody.

Initial evidence for sex-specific effects of early emotional abuse on affective processing in bipolar disorder

PurposeThis study investigates the effect of sex and childhood trauma on affective processing in bipolar disorder (BPD) patients. MethodsIn a sample of fifty-six BPD patients, we administered the Childhood Trauma Questionnaire (CTQ), and the Iowa Gambling Task (IGT) and the Affective Go/No-Go (AGNG) to measure affective processing. Analysis of Variance (ANOVA) was used to evaluate the effect of sex and childhood trauma on IGT; Repeated-Measures ANOVAs to measure accuracy and bias measures across conditions on the AGNG. ResultsIn the context of childhood abuse, females evidenced a more conservative cognitive style than males by selecting fewer cards from the disadvantageous decks [F(1, 49)=14.218; P<0.001] and showed an improvement throughout the task, as noted in a normal learning curve [F(1.49)=4.385; P=0.041)]. For the AGNG, an interaction specific to the negative valence stimuli on response bias measures was found. Abused females scored higher (mean=8.38; SD=6.39) than abused males (mean=0.69; SD=1.19) [F(1.46)=6.348; P=0.015]. ConclusionSeverity of childhood trauma was significantly different between sexes. In the context of a history of emotional abuse, male bipolar patients tended toward a more risk-taking behavior compared to female. Further investigations are needed to elucidate potential pathophysiological mechanisms underlying this interaction.

Altered affective processing in bipolar disorder: An fMRI study

BackgroundPrevious studies have reported that patients with bipolar disorder (BPD) exhibit altered emotional processing and regulation. However, results remain largely inconsistent across studies. The aim of the current study was to further examine affective processing in patients with bipolar disorder. MethodsTwenty-three patients diagnosed with BPD (Type I) and 18 healthy matched controls completed a backward-masked affect paradigm while undergoing functional magnetic resonance imaging. Participants also completed a computerized, overt task of facial emotional discrimination after scanning. ResultsResults demonstrated altered affective processing of happy and fearful stimuli in bipolar participants in the amygdala, anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC) relative to controls. BPD participants also displayed significant deficits in identifying fearful facial affect. LimitationsThis study has a moderate sample size, and the patients with BPD were significantly older than the healthy control participants; this did not appear to impact results, and although statistically significant, it is not likely biologically significant. ConclusionsThese findings may have implications for patients with BPD, as altered affective processing could result in deficits in reading social cues.

Visual context processing in bipolar disorder: a comparison with schizophrenia

Anomalous perception has been investigated extensively in schizophrenia, but it is unclear whether these impairments are specific to schizophrenia or extend to other psychotic disorders. Recent studies of visual context processing in schizophrenia (Tibber et al., 2013; Yang et al., 2013) point to circumscribed, task-specific abnormalities. Here we examined visual contextual processing across a comprehensive set of visual tasks in individuals with bipolar disorder and compared their performance with that of our previously published results from schizophrenia and healthy participants tested on those same tasks. We quantified the degree to which the surrounding visual context alters a center stimulus' appearance for brightness, size, contrast, orientation and motion. Across these tasks, healthy participants showed robust contextual effects, as indicated by pronounced misperceptions of the center stimuli. Participants with bipolar disorder showed contextual effects similar in magnitude to those found in healthy participants on all tasks. This result differs from what we found in schizophrenia participants (Yang et al., 2013) who showed weakened contextual modulations of contrast but intact contextual modulations of perceived luminance and size. Yet in schizophrenia participants, the magnitude of the contrast illusion did not correlate with symptom measures. Performance on the contrast task by the bipolar disorder group also could not be distinguished from that of the schizophrenia group, and this may be attributed to the result that bipolar patients who presented with greater manic symptoms showed weaker contrast modulation. Thus, contrast gain control may be modulated by clinical state in bipolar disorder. Stronger motion and orientation context effects correlated with worse clinical symptoms across both patient groups and especially in schizophrenia participants. These results highlight the complexity of visual context processing in schizophrenia and bipolar disorder.

The HLA-G low expressor genotype is associated with protection against bipolar disorder

Implication of immune processes in bipolar disorder (BD) has recently gained increasing attention. Tolerogenic molecules, among which HLA-G plays a prominent role, mediate the modulation of such processes. The HLA-G locus is characterized by a high number of polymorphisms including a functionally relevant 14 base pair (bp) insertion/deletion (Ins/Del) allele affecting the HLA-G expression. Here, we analyzed the distribution of this polymorphism in 561 BD patients and 161 healthy and found that the HLA-G 14bp Ins/Ins genotype was significantly more prevalent in healthy controls than in patients (corrected p; pc=0.032) and that the prevalence of such protective genotype is lower among patients born during the winter season as compared to those born in other periods (pc=0.006). Possible mechanisms between low HLA G expression and resistance to infections as well as potential relationships between infections in early life and susceptibility to BD are discussed.

Perturbations de la réactivité émotionnelle et du sommeil dans les troubles bipolaires en période intercritique

Emotional reactivity and sleep constitute key dimensions of bipolar disorder. Emotional reactivity referred to emotion response intensity and emotion response threshold. Higher emotion reactivity is described during both mood episodes and periods of remission in bipolar disorder. As well, sleep disturbances are described during both acute episodes and euthymic periods in bipolar disorder. Links between sleep and emotion regulation start to be studied in general population. Interactions between sleep and emotion systems can rely on shared neuronal structures, which involve limbic system. Future research on sleep and emotion regulation relationships is required in bipolar disorder. A systematic review of the scientific literature was conducted. Studies on emotional reactivity in bipolar disorder during periods of remission were presented. Sleep studies of bipolar disorder during inter-critical periods were discussed too. Researches on interactions between sleep and emotion regulation in general population were presented. Finally, therapeutic applications focusing on sleep and emotional regulation in bipolar disorder were described. Patients with bipolar disorder display disturbances of sleep and emotion reactivity even during periods of remission. Indeed, bipolar patients display more intense and more labile emotions assessed by self-questionnaires, increase positive attribution to neutral stimuli corroborated by startle reflex, functional changing on imagery studies. Sleep disturbances during inter-critical periods refer to clinical poor sleep quality and to increase time in bed, more frequent nocturnal awaking, more variable sleep-wake patterns assessed by actigraphy and polysomnography. In general population some studies have shown the impact of sleep restriction on emotion dysregulation. F-MRI studies show that healthy participants present increase activation of some structures such as amygdala involved in emotion processing. Deregulation of these areas has already been noticed in previous studies of euthymic bipolar patients without sleep restriction procedure. Considering sleep and emotion processes enhance our understanding of medication action mechanisms. Lithium and sodium valproate reduce melatonin light sensitivity and increased the activity period. It can be postulated that these effects on circadian system can impact sleep regulation. Furthermore, an f-MRI study shows that mood stabilizers can reduce amygdala activation of bipolar patients compared to untreated bipolar patients during an emotional task. Emotion and sleep regulation can be targeted by specific psychotherapy. Interpersonal and social rhythm therapy, cognitive behavioral therapy of insomnia and mindfulness applied to bipolar disorder are presented and discussed. Disturbances of sleep and emotional reactivity remain during periods of remission in bipolar disorder. Further research is required to better understand relationships between these two processes in bipolar disorder. Sleep and emotion dysgulations can be targeted by specific psychotherapy. More systematic assessment of sleep an emotional reactivity in remitted bipolar patients can lead to consider and treat this residual symptomatology that could reduce recurrences.

Evidence of diagnostic specificity in the neural correlates of facial affect processing in bipolar disorder and schizophrenia: a meta-analysis of functional imaging studies

Schizophrenia (SZ) and bipolar disorder (BD) may overlap in etiology and phenomenology but differ with regard to emotional processing. We used facial affect as a probe for emotional processing to determine whether there are diagnosis-related differences between SZ and BD in the function of the underlying neural circuitry. Functional magnetic resonance imaging (fMRI) studies published up to 30 April 2012 investigating facial affect processing in patients with SZ or BD were identified through computerized and manual literature searches. Activation foci from 29 studies encompassing 483 healthy individuals, 268 patients with SZ and 267 patients with BD were subjected to voxel-based quantitative meta-analysis using activation likelihood estimation (ALE). Compared to healthy individuals, when emotional facial stimuli were contrasted to neutral stimuli, patients with BD showed overactivation within the parahippocampus/amygdala and thalamus and reduced engagement within the ventrolateral prefrontal cortex (PFC) whereas patients with SZ showed underactivation throughout the entire facial affect processing network and increased activation in visual processing regions within the cuneus. Patients with BD showed greater thalamic engagement compared to patients with SZ; in the reverse comparison, patients with SZ showed greater engagement in posterior associative visual cortices. During facial affect processing, patients with BD show overactivation in subcortical regions and underactivation in prefrontal regions of the facial affect processing network, consistent with the notion of reduced emotional regulation. By contrast, overactivation within visual processing regions coupled with reduced engagement of facial affect processing regions points to abnormal visual integration as the core underlying deficit in SZ.

The impact of CACNA1C allelic variation on effective connectivity during emotional processing in bipolar disorder

The impact of CACNA1C allelic variation on effective connectivity during emotional processing in bipolar disorder

Event-related potential examination of facial affect processing in bipolar disorder and schizophrenia

Patients with bipolar disorder exhibit consistent deficits in facial affect identification at both behavioral and neural levels. However, little is known about which stages of facial affect processing are dysfunctional. Event-related potentials (ERPs), including amplitude and latency, were used to evaluate two stages of facial affect processing: N170 to examine structural encoding of facial features and N250 to examine decoding of facial features in 57 bipolar disorder patients, 30 schizophrenia patients and 30 healthy controls. Three conditions were administered: participants were asked to identify the emotion of a face, the gender of a face, or whether a building was one or two stories tall. Schizophrenia patients' emotion identification accuracy was lower than that of bipolar patients and healthy controls. N170 amplitude was significantly smaller in schizophrenia patients compared to bipolar patients and healthy controls, which did not differ from each other. Both patient groups had significantly longer N170 latency compared to healthy controls. For N250, both patient groups showed significantly smaller amplitudes compared with controls, but did not differ from each other. Bipolar patients showed longer N250 latency than healthy controls; patient groups did not differ from each other. Bipolar disorder patients have relatively intact structural encoding of faces (N170) but are impaired when decoding facial features for complex judgments about faces (N250 latency and amplitude), such as identifying emotion or gender.

Trait and state corticostriatal dysfunction in bipolar disorder during emotional face processing

Convergent evidence supports limbic, anterior paralimbic, and prefrontal cortex (PFC) abnormalities in emotional processing in bipolar disorder (BD) and suggests that some abnormalities are mood-state dependent and others persist into euthymia. However, few studies have assessed elevated, depressed, and euthymic mood states while individuals processed emotional stimuli of varying valence to investigate trait- and state-related neural system responses. Here, regional brain responses to positive, negative, and neutral emotional stimuli were assessed in individuals with BD during elevated, depressed, and euthymic mood states. One hundred and thirty-four subjects participated in functional magnetic resonance imaging scanning while processing faces depicting happy, fearful, and neutral expressions: 76 with BD (18 in elevated mood states, 19 depressed, 39 euthymic) and 58 healthy comparison (HC) individuals. Analyses were performed for BD trait- and mood state-related features. Ventral anterior cingulate cortex (VACC), orbitofrontal cortex (OFC), and ventral striatum responses to happy and neutral faces were decreased in the BD group, compared to the HC group, and were not influenced by mood state. Elevated mood states were associated with decreased right rostral PFC activation to fearful and neutral faces, and depression was associated with increased left OFC activation to fearful faces. The findings suggest that abnormal VACC, OFC, and ventral striatum responses to happy and neutral stimuli are trait features of BD. Acute mood states may be associated with additional lateralized abnormalities of diminished right rostral PFC responses to fearful and neutral stimuli in elevated states and increased left OFC responses to fearful stimuli in depressed states.

Amygdala activity and prefrontal cortex–amygdala effective connectivity to emerging emotional faces distinguish remitted and depressed mood states in bipolar disorder

Few studies have employed effective connectivity (EC) to examine the functional integrity of neural circuitry supporting abnormal emotion processing in bipolar disorder (BD), a key feature of the illness. We used Granger Causality Mapping (GCM) to map EC between the prefrontal cortex (PFC) and bilateral amygdala and a novel paradigm to assess emotion processing in adults with BD. Thirty-one remitted adults with BD [(remitted BD), mean age = 32 years], 21 adults with BD in a depressed episode [(depressed BD), mean age = 33 years], and 25 healthy control participants [(HC), mean age = 31 years] performed a block-design emotion processing task requiring color-labeling of a color flash superimposed on a task-irrelevant face morphing from neutral to emotional (happy, sad, angry, or fearful). GCM measured EC preceding (top-down) and following (bottom-up) activity between the PFC and the left and right amygdalae. Our findings indicated patterns of abnormally elevated bilateral amygdala activity in response to emerging fearful, sad, and angry facial expressions in remitted-BD subjects versus HC, and abnormally elevated right amygdala activity to emerging fearful faces in depressed-BD subjects versus HC. We also showed distinguishable patterns of abnormal EC between the amygdala and dorsomedial and ventrolateral PFC, especially to emerging happy and sad facial expressions in remitted-BD and depressed-BD subjects. EC measures of neural system level functioning can further understanding of neural mechanisms associated with abnormal emotion processing and regulation in BD. Our findings suggest major differences in recruitment of amygdala-PFC circuitry, supporting implicit emotion processing between remitted-BD and depressed-BD subjects, which may underlie changes from remission to depression in BD.

Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study

BackgroundCognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients.Methods12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated.Results(1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex.ConclusionsIndividuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.

Delayed early face processing in bipolar disorder

Bipolar disorder primarily encompasses mood symptom states of depression and mania separated by symptom-free euthymia, and patients also exhibit cognitive deficits that include face processing. However, there is minimal extant event-related potential (ERP) research investigating the time course of these impairments. The aim of the present study was to contribute to a greater understanding of the specific stages of face processing that are impaired in bipolar disorder. Bipolar and age-matched and sex-matched control individuals completed an emotional go/no-go paradigm involving happy and sad face stimuli during ERP acquisition. Amplitudes and latencies of frontocentral P80, N120 and vertex positive potential (VPP) ERP components were analysed in response to 'go' stimuli. Across groups, VPP latencies were reduced in response to sad compared with happy face stimuli. Between groups, individuals with bipolar disorder demonstrated overall increased latencies in P80 and VPP ERP components. Current and previous studies suggest that patients with bipolar disorder exhibit early visual processing deficits, but the present study contributes new evidence of a deficit in the visual P80 ERP. Delayed neural responses may be an ERP correlate of white matter deficits that have previously been identified. Furthermore, implications for early visual impairments may involve behavioural symptoms downstream.

Dissociable patterns of medial prefrontal and amygdala activity to face identityversusemotion in bipolar disorder

Individuals with bipolar disorder demonstrate abnormal social function. Neuroimaging studies in bipolar disorder have shown functional abnormalities in neural circuitry supporting face emotion processing, but have not examined face identity processing, a key component of social function. We aimed to elucidate functional abnormalities in neural circuitry supporting face emotion and face identity processing in bipolar disorder. Twenty-seven individuals with bipolar disorder I currently euthymic and 27 healthy controls participated in an implicit face processing, block-design paradigm. Participants labeled color flashes that were superimposed on dynamically changing background faces comprising morphs either from neutral to prototypical emotion (happy, sad, angry and fearful) or from one identity to another identity depicting a neutral face. Whole-brain and amygdala region-of-interest (ROI) activities were compared between groups. There was no significant between-group difference looking across both emerging face emotion and identity. During processing of all emerging emotions, euthymic individuals with bipolar disorder showed significantly greater amygdala activity. During facial identity and also happy face processing, euthymic individuals with bipolar disorder showed significantly greater amygdala and medial prefrontal cortical activity compared with controls. This is the first study to examine neural circuitry supporting face identity and face emotion processing in bipolar disorder. Our findings of abnormally elevated activity in amygdala and medial prefrontal cortex (mPFC) during face identity and happy face emotion processing suggest functional abnormalities in key regions previously implicated in social processing. This may be of future importance toward examining the abnormal self-related processing, grandiosity and social dysfunction seen in bipolar disorder.

Common and distinct neural correlates of emotional processing in Bipolar Disorder and Major Depressive Disorder: A voxel-based meta-analysis of functional magnetic resonance imaging studies

Neuroimaging studies have consistently shown functional brain abnormalities in patients with Bipolar Disorder (BD) and Major Depressive Disorder (MDD). However, the extent to which these two disorders are associated with similar or distinct neural changes remains unclear. We conducted a systematic review of functional magnetic resonance imaging studies comparing BD and MDD patients to healthy participants using facial affect processing paradigms. Relevant spatial coordinates from twenty original studies were subjected to quantitative Activation Likelihood Estimation meta-analyses based on 168 BD and 189 MDD patients and 344 healthy controls. We identified common and distinct patterns of neural engagement for BD and MDD within the facial affect processing network. Both disorders were associated with increased engagement of limbic regions. Diagnosis-specific differences were observed in cortical, thalamic and striatal regions. Decreased ventrolateral prefrontal cortical engagement was associated with BD while relative hypoactivation of the sensorimotor cortices was seen in MDD. Increased responsiveness in the thalamus and basal ganglia were associated with BD. These findings were modulated by stimulus valence. These data suggest that whereas limbic overactivation is reported consistently in patients with mood disorders, future research should consider the relevance of a wider network of regions in formulating conceptual models of BD and MDD.

Neural correlates of emotional face processing in bipolar disorder: An event-related potential study

Behavioural and imaging studies report that individuals with bipolar disorder (BD) exhibit impairments in emotional face processing. However, few studies have studied the temporal characteristics of these impairments, and event-related potential (ERP) studies that investigate emotion perception in BD are rare. The aim of our study was to explore these processes as indexed by the face-specific P100 and N170 ERP components in a BD cohort. Eighteen subjects diagnosed with BD and 18 age- and sex-matched healthy volunteers completed an emotional go/no-go inhibition task during electroencephalogram (EEG) and ERP acquisition. Patients demonstrated faster responses to happy compared to sad faces, whereas control data revealed no emotional discrimination. Errors of omission were more frequent in the BD group in both emotion conditions, but there were no between-group differences in commission errors. Significant differences were found between groups in P100 amplitude variation across levels of affect, with the BD group exhibiting greater responses to happy compared to sad faces. Conversely, the control cohort failed to demonstrate a differentiation between emotions. A statistically significant between-group effect was also found for N170 amplitudes, indicating reduced responses in the BD group. Future studies should ideally recruit BD patients across all three mood states (manic, depressive, and euthymic) with greater scrutiny of the effects of psychotropic medication. These ERP results primarily suggest an emotion-sensitive face processing impairment in BD whereby patients are initially more attuned to positive emotions as indicated by the P100 ERP component, and this may contribute to the emergence of bipolar-like symptoms.

Impairments in “top-down” processing in bipolar disorder: A simultaneous fMRI–GSR study

Understanding the underlying neurobiology of bipolar disorder especially in the euthymic state is essential to furthering our understanding of pertinent psychiatric questions involving the observed symptomatology of the illness. In this study we investigated the mechanisms that underpin the modulation of affect in bipolar disorder to examine the contributions of cortico-limbic brain networks in the processing of affect. We employed a simultaneous functional magnetic resonance imaging and galvanic skin response methodology to investigate top-down networks in euthymic bipolar patients and healthy controls. Galvanic skin responsivity was used to partition neural epochs in which arousal pertaining to the appreciation of disgust stimuli was processed. The results of this study demonstrate that patients with bipolar disorder exhibited impairments in the recruitment of top-down brain networks and as such were unable to engage, to the same extent as matched controls, essential prefrontal processing needed to evaluate emotional salience. Partitioning top-down networks on the basis of arousal measures provided a context within which the modulation of brain networks specialised for the processing of emotion, as well as their interplay with other brain regions including the frontal lobes, could be studied.

Circadian rhythms and sleep in bipolar disorder

Biological rhythm pathways are highlighted in a number of etiological models of bipolar disorder, and the management of circadian instability appears in consensus treatment guidelines. There are, however, significant conceptual and empirical limitations on our understanding of a hypothesised link between circadian, sleep, and emotion regulation processes in bipolar disorder. The aim of this article is to articulate the limits of scientific knowledge in relation to this hypothesis. A critical evaluation of various literatures was undertaken. The basic science of circadian and sleep processes, their involvement in normal emotion regulation, and the types of evidence suggesting circadian/sleep involvement in bipolar disorder are reviewed. Multiple lines of evidence suggest that circadian and sleep-wake processes are causally involved in bipolar disorder. These processes demonstrably interact with other neurobiological pathways known to be important in bipolar disorder, but are unique in that they are open to behavioural manipulation. Further research into biological rhythm pathways to bipolar disorder is warranted. Person-environment feedback loops are fundamental to circadian adaptation, and models of circadian pathogenesis (and treatment) should recognize this complexity.

Early life stressors and genetic influences on the development of bipolar disorder: The roles of childhood abuse and brain-derived neurotrophic factor

Objectives Although there is increasing research exploring the psychosocial influences and biological underpinnings of bipolar disorder, relatively few studies have specifically examined the interplay between these factors in the development of this illness. Social–biological models within a developmental psychopathology perspective are necessary to advance our understanding of the processes involved in the onset and course of bipolar disorder. This article presents a review of the empirical literature linking childhood abuse to bipolar disorder, the research to date on the possible role of brain-derived neurotrophic factor (BDNF) in the development of this disorder, followed by a discussion of how childhood abuse may interact with BDNF. Methods A literature search was conducted using Psycinfo to identify relevant articles on childhood abuse, BDNF, and bipolar disorder. Results The extant research implicates both childhood abuse and BDNF in the etiology of bipolar disorder. Specifically, there is growing evidence associating early abuse to the development of bipolar disorder. Similarly, the BDNF Val66 allele has been linked with increased susceptibility to bipolar disorder. Based on existing research, a genetic diathesis-transactional stress model is proposed incorporating childhood abuse and the BDNF gene in the pathogenesis of bipolar disorder. Conclusions Although there is some support for this model, the relatively modest amount of relevant literature highlights the need for further research. An integrative theoretical framework including both social and biological processes in bipolar disorder is important for the development of effective prevention and treatment strategies for this disorder.

Perturbed reward processing in pediatric bipolar disorder: an antisaccade study

Pediatric bipolar disorder is a severe and impairing illness. Characterizing the impact of pediatric bipolar disorder on cognitive function might aid in understanding the phenomenology of the disorder. While previous studies of pediatric bipolar disorder have reported deficits in cognitive control and reward behavior, little is understood about how affective processes influence behavioral control. Relative to prior studies using manual-response paradigms, eye movement tasks provide a more precise assessment of reward sensitivity and cognitive and motor control. The current study compares 20 youths with bipolar disorder (mean age = 13.9 years ± 2.22) and 23 healthy subjects (mean age = 13.8 years ± 2.49) on a mixed pro-antisaccade task with monetary incentives. On both types of saccades, participants were presented with three types of incentives: those where subjects can win money, lose money, or neither win nor lose money. Impaired reward processing was found in youths with bipolar disorder relative to controls, particularly on antisaccades. This difference was reflected in lower error rates during incentive trials in the control but not in the bipolar disorder group. By comparison, no group differences were found on prosaccade trials. The results provide further evidence for deficits in cognitive and reward processing in bipolar disorder.