Modulation of brain response to emotional conflict as a function of current mood in bipolar disorder: preliminary findings from a follow-up state-based fMRI study

Towards a neurodevelopmental model of bipolar disorder: a critical review of trait- and state-related functional neuroimaging in adolescents and young adults

Neurodevelopmental mechanisms are increasingly implicated in bipolar disorder (BD), highlighting the importance of their study in young persons. Neuroimaging studies have demonstrated a central role for frontotemporal corticolimbic brain systems that subserve processing and regulation of emotions, and processing of reward in adults with BD. As adolescence and young adulthood (AYA) is a time when fully syndromal BD often emerges, and when these brain systems undergo dynamic maturational changes, the AYA epoch is implicated as a critical period in the neurodevelopment of BD. Functional magnetic resonance imaging (fMRI) studies can be especially informative in identifying the functional neuroanatomy in adolescents and young adults with BD (BDAYA) and at high risk for BD (HR-BDAYA) that is related to acute mood states and trait vulnerability to the disorder. The identification of early emerging brain differences, trait- and state-based, can contribute to the elucidation of the developmental neuropathophysiology of BD, and to the generation of treatment and prevention targets. In this critical review, fMRI studies of BDAYA and HR-BDAYA are discussed, and a preliminary neurodevelopmental model is presented based on a convergence of literature that suggests early emerging dysfunction in subcortical (e.g., amygdalar, striatal, thalamic) and caudal and ventral cortical regions, especially ventral prefrontal cortex (vPFC) and insula, and connections among them, persisting as trait-related features. More rostral and dorsal cortical alterations, and bilaterality progress later, with lateralization, and direction of functional imaging findings differing by mood state. Altered functioning of these brain regions, and regions they are strongly connected to, are implicated in the range of symptoms seen in BD, such as the insula in interoception, precentral gyrus in motor changes, and prefrontal cortex in cognition. Current limitations, and outlook on the future use of neuroimaging evidence to inform interventions and prevent the onset of mood episodes in BDAYA, are outlined.

Effects of contextualized emotional conflict control on domain-general conflict control: fMRI evidence of neural network reconfiguration

Domain-general conflict control refers to the cognitive process in which individuals suppress task-irrelevant information and extract task-relevant information. It supports both effective implementation of cognitive conflict control and emotional conflict control. The present study employed functional magnetic resonance imaging and adopted an emotional valence conflict task and the arrow version of the flanker task to induce contextualized emotional conflicts and cognitive conflicts, respectively. The results from the conjunction analysis showed that the multitasking-related activity in the pre-supplementary motor area, bilateral dorsal premotor cortices, the left posterior intraparietal sulcus (IPS), the left anterior IPS and the right inferior occipital gyrus represents common subprocesses for emotional and cognitive conflict control, either in parallel or in close succession. These brain regions were used as nodes in the domain-general conflict control network. The results from the analyses on the brain network connectivity patterns revealed that emotional conflict control reconfigures the domain-general conflict control network in a connective way as evidenced by different communication and stronger connectivity among the domain-general conflict control network. Together, these findings offer the first empirical-based elaboration on the brain network underpinning emotional conflict control and how it reconfigures the domain-general conflict control network in interactive ways.

Is brain perfusion correlated to switching mood states and cognitive impairment in bipolar disorder type I? A longitudinal study using perfusion imaging approach

Type I Bipolar disorder (BD-I) is a neuropsychiatric disorder characterized by manic or mixed-featured episodes, impaired cognitive functioning, and persistent work and social functioning impairment. This study aimed to investigate within-subject; (i) differences in brain perfusion using Single-photon emission computed tomography (SPECT) between manic and euthymic states in BD-I patients; (ii) explore potential associations between altered brain perfusion and cognitive status; and (iii) examine the relationship between cerebral perfusion and mania symptom ratings. Seventeen adult patients diagnosed with BD-I in a manic episode were recruited, and clinical assessments, cognitive tests, and brain perfusion studies were conducted at baseline (mania state) and a follow-up visit 6 months later. The results showed cognitive impairment during the manic episode, which persisted during the euthymic state at follow-up. However, no significant changes in brain perfusion were observed between the manic and euthymic states. During mania, trends toward decreased perfusion in the left cerebellum and right superior parietal lobule were noted. Additionally, trends indicated a higher perfusion imbalance in the left superior and middle frontal gyrus during mania and the right superior and middle frontal gyrus during euthymia. No significant correlations existed between brain perfusion, mania symptom ratings, and cognitive performance, indicating that symptomatology might represent more than neural hemodynamics. These findings suggest that cognitive impairment may persist in BD-I patients and highlight the need for therapeutic interventions targeting cognitive deficits. More extensive studies with extended follow-up periods are warranted further to investigate brain perfusion and cognitive functioning in BD-I patients.

Altered frequency-specific/universal amplitude characteristics of spontaneous brain oscillations in patients with bipolar disorder

The human brain is a dynamic system with intrinsic oscillations in spontaneous neural activity. Whether the dynamic characteristics of these spontaneous oscillations are differentially altered across different frequency bands in patients with bipolar disorder (BD) remains unclear. This study recruited 65 patients with BD and 85 healthy controls (HCs). The entire frequency range of resting-state fMRI data was decomposed into four frequency intervals. Two-way repeated-measures ANCOVA was employed to detect frequency-specific/universal alterations in the dynamic oscillation amplitude in BD. The patients were then divided into two subgroups according to their mood states to explore whether these alterations were independent of their mood states. Finally, other window sizes, step sizes, and window types were tested to replicate all analyses. Frequency-specific abnormality of the dynamic oscillation amplitude was detected within the posterior medial parietal cortex (centered at the precuneus extending to the posterior cingulate cortex). This specific profile indicates decreased amplitudes in the lower frequency bands (slow-5/4) and no amplitude changes in the higher frequency bands (slow-3/2) compared with HCs. Frequency-universal abnormalities of the dynamic oscillation amplitude were also detectable, indicating increased amplitudes in the thalamus and left cerebellum anterior lobe but decreased amplitudes in the medial superior frontal gyrus. These alterations were independent of the patients' mood states and replicable across multiple analytic and parametric settings. In short, frequency-specific/universal amplitude characteristics of spontaneous oscillations were observed in patients with BD. These abnormal characteristics have important implications for specific functional changes in BD from multiple frequency and dynamic perspectives.

Normalization of impaired emotion inhibition in bipolar disorder mediated by cholinergic neurotransmission in the cingulate cortex

The muscarinic-cholinergic system is involved in the pathophysiology of bipolar disorder (BD), and contributes to attention and the top-down and bottom-up cognitive and affective mechanisms of emotional processing, functionally altered in BD. Emotion processing can be assessed by the ability to inhibit a response when the content of the image is emotional. Impaired regulatory capacity of cholinergic neurotransmission conferred by reduced M₂-autoreceptor availability is hypothesized to play a role in elevated salience of negative emotional distractors in euthymic BD relative to individuals with no history of mood instability. Thirty-three euthymic BD type-I (DSM-V-TR) and 50 psychiatrically-healthy controls underwent functional magnetic resonance imaging (fMRI) and an emotion-inhibition paradigm before and after intravenous cholinergic challenge using the acetylcholinesterase inhibitor, physostigmine (1 mg), or placebo. Mood, accuracy, and reaction time on either recognizing or inhibiting a response associated with an image involving emotion and regional functional activation were examined for effects of cholinergic challenge physostigmine relative to placebo, prioritizing any interaction with the diagnostic group. Analyses revealed that (1) at baseline, impaired behavioral performance was associated with lower activation in the anterior cingulate cortex in BD relative to controls during emotion processing; (2) physostigmine (vs. placebo) affected behavioral performance during the inhibition of negative emotions, without altering mood, and increased activation in the posterior cingulate cortex in BD (vs. controls); (3) In BD, lower accuracy observed during emotion inhibition of negative emotions was remediated by physostigmine and was associated with cingulate cortex overactivation. Our findings implicate abnormal regulation of cholinergic neurotransmission in the cingulate cortices in BD, which may mediate exaggerated emotional salience processing, a core feature of BD.

Is emotion regulation impacted by executive functions? An experimental study

The ability to exert influence on our emotions plays a significant role in the attainment of our goals. To have control over when and how we experience emotions is thought to be impacted by higher cognitive processes such as executive functions. However, there is inadequate research to support this notion. Hence, we examined the relationship between executive functions - updating, shifting, and inhibition - and emotion regulation strategies - cognitive reappraisal and expressive suppression. We predicted that updating would positively relate to cognitive reappraisal, while inhibition would positively relate to expressive suppression. Shifting would positively relate to both cognitive reappraisal and expressive suppression. Participants completed updating, shifting, and inhibition tasks. Then, they used expressive suppression or cognitive reappraisal strategies in response to unpleasant pictures, accompanied by a physiological recording. Faster updating was associated with a larger heart rate deceleration during reappraisal. Inhibition was associated with more frequent use of suppression. Overall, the results confirm the idea that a higher level of executive functions is partially related to the effective application of emotion regulation strategies. The content of executive function tasks does not affect the association between executive functions and emotion regulation. These findings are important for psychotherapy, as training executive functions could partially help in the treatment of mood-related disorders.

Amygdala in Action: Functional Connectivity during Approach and Avoidance Behaviors

Motivation is an important feature of emotion. By driving approach to positive events and promoting avoidance of negative stimuli, motivation drives adaptive actions and goal pursuit. The amygdala has been associated with a variety of affective processes, particularly the appraisal of stimulus valence that is assumed to play a crucial role in the generation of approach and avoidance behaviors. Here, we measured amygdala functional connectivity patterns while participants played a video game manipulating goal conduciveness through the presence of good, neutral, or bad monsters. As expected, good versus bad monsters elicited opposing motivated behaviors, whereby good monsters induced more approach and bad monsters triggered more avoidance. These opposing directional behaviors were paralleled by increased connectivity between the amygdala and medial brain areas, such as the OFC and posterior cingulate, for good relative to bad, and between amygdala and caudate for bad relative to good monsters. Moreover, in both conditions, individual connectivity strength between the amygdala and medial prefrontal regions was positively correlated with brain scores from a latent component representing efficient goal pursuit, which was identified by a partial least square analysis determining the multivariate association between amygdala connectivity and behavioral motivation indices during gameplay. At the brain level, this latent component highlighted a widespread pattern of amygdala connectivity, including a dorsal frontoparietal network and motor areas. These results suggest that amygdala-medial prefrontal interactions captured the overall subjective relevance of ongoing events, which could consecutively drive the engagement of attentional, executive, and motor circuits necessary for implementing successful goal-pursuit, irrespective of approach or avoidance directions.

Fronto-limbic neural variability as a transdiagnostic correlate of emotion dysregulation

Emotion dysregulation is central to the development and maintenance of psychopathology, and is common across many psychiatric disorders. Neurobiological models of emotion dysregulation involve the fronto-limbic brain network, including in particular the amygdala and prefrontal cortex (PFC). Neural variability has recently been suggested as an index of cognitive flexibility. We hypothesized that within-subject neural variability in the fronto-limbic network would be related to inter-individual variation in emotion dysregulation in the context of low affective control. In a multi-site cohort (N = 166, 93 females) of healthy individuals and individuals with emotional dysregulation (attention deficit/hyperactivity disorder (ADHD), bipolar disorder (BD), and borderline personality disorder (BPD)), we applied partial least squares (PLS), a multivariate data-driven technique, to derive latent components yielding maximal covariance between blood-oxygen level-dependent (BOLD) signal variability at rest and emotion dysregulation, as expressed by affective lability, depression and mania scores. PLS revealed one significant latent component (r = 0.62, p = 0.044), whereby greater emotion dysregulation was associated with increased neural variability in the amygdala, hippocampus, ventromedial, dorsomedial and dorsolateral PFC, insula and motor cortex, and decreased neural variability in occipital regions. This spatial pattern bears a striking resemblance to the fronto-limbic network, which is thought to subserve emotion regulation, and is impaired in individuals with ADHD, BD, and BPD. Our work supports emotion dysregulation as a transdiagnostic dimension with neurobiological underpinnings that transcend diagnostic boundaries, and adds evidence to neural variability being a relevant proxy of neural efficiency.

Alterations in the default mode-salience network circuit provide a potential mechanism supporting negativity bias in depression

Aberrant effective connectivity between default mode (DMN) and salience (SAL) networks may support the tendency of depressed individuals to find it difficult to disengage from self-focused, negatively-biased thinking and may contribute to the onset and maintenance of depression. Assessment of effective connectivity, which can statistically characterize the direction of influence between regions within neural circuits, may provide new insights into the nature of DMN-SAL connectivity disruptions in depression. Functional magnetic resonance imaging (fMRI) was collected from 38 individuals with a history of major depression and 50 healthy comparison participants during completion of an emotion-word Stroop task. Activation within DMN and SAL networks and effective connectivity between DMN and SAL, assessed via Granger causality, were examined. Individuals with a history of depression exhibited greater overall network activation, greater directed connectivity from DMN to SAL, and less directed connectivity from SAL to DMN than healthy comparison participants during negative-word trials. Among individuals with a history of depression, greater DMN-to-SAL connectivity was associated with lower overall network activation and worse task performance during positive-word trials; this pattern was not observed among healthy participants. Present findings indicate that greater network activation and, specifically, influence of DMN on SAL, support negativity bias among previously depressed individuals.

Dynamics of amygdala connectivity in bipolar disorders: a longitudinal study across mood states

Alterations in activity and connectivity of brain circuits implicated in emotion processing and emotion regulation have been observed during resting-state for different clinical phases of bipolar disorders (BD), but longitudinal investigations across different mood states in the same patients are still rare. Furthermore, measuring dynamics of functional connectivity patterns offers a powerful method to explore changes in the brain's intrinsic functional organization across mood states. We used a novel co-activation pattern (CAP) analysis to explore the dynamics of amygdala connectivity at rest in a cohort of 20 BD patients prospectively followed-up and scanned across distinct mood states: euthymia (20 patients; 39 sessions), depression (12 patients; 18 sessions), or mania/hypomania (14 patients; 18 sessions). We compared them to 41 healthy controls scanned once or twice (55 sessions). We characterized temporal aspects of dynamic fluctuations in amygdala connectivity over the whole brain as a function of current mood. We identified six distinct networks describing amygdala connectivity, among which an interoceptive-sensorimotor CAP exhibited more frequent occurrences during hypomania compared to other mood states, and predicted more severe symptoms of irritability and motor agitation. In contrast, a default-mode CAP exhibited more frequent occurrences during depression compared to other mood states and compared to controls, with a positive association with depression severity. Our results reveal distinctive interactions between amygdala and distributed brain networks in different mood states, and foster research on interoception and default-mode systems especially during the manic and depressive phase, respectively. Our study also demonstrates the benefits of assessing brain dynamics in BD.

Dynamic functional brain networks underlying the temporal inertia of negative emotions

Affective inertia represents the lasting impact of transient emotions at one time point on affective state at a subsequent time point. Here we describe the neural underpinnings of inertia following negative emotions elicited by sad events in movies. Using a co-activation pattern analysis of dynamic functional connectivity, we examined the temporal expression and reciprocal interactions among brain-wide networks during movies and subsequent resting periods in twenty healthy subjects. Our findings revealed distinctive spatiotemporal expression of visual (VIS), default mode (DMN), central executive (CEN), and frontoparietal control (FPCN) networks both in negative movies and in rest periods following these movies. We also identified different reciprocal relationships among these networks, in transitions from movie to rest. While FPCN and DMN expression increased during and after negative movies, respectively, FPCN occurrences during the movie predicted lower DMN and higher CEN expression during subsequent rest after neutral movies, but this relationship was reversed after the elicitation of negative emotions. Changes in FPCN and DMN activity correlated with more negative subjective affect. These findings provide new insights into the transient interactions of intrinsic brain networks underpinning the inertia of negative emotions. More specifically, they describe a major role of FPCN in emotion elicitation processes, with prolonged impact on DMN activity in subsequent rest, presumably involved in emotion regulation and restoration of homeostatic balance after negative events.

Functional connectivity between the ventral anterior cingulate and amygdala during implicit emotional conflict regulation and daily-life emotion dysregulation

Emotional conflict adaptation involving ventral anterior cingulate cortex (ACC) suppression of the amygdala is thought to be important in emotion regulation, with evidence of impaired implicit emotion regulation in emotional distress disorders. However, it is unclear how this impairment is associated with daily-life emotion dysregulation in emotional distress disorders. In the current study, female participants with an emotional distress disorder (N = 27) were scanned with MRI while completing an implicit emotion conflict regulation task that involved identifying the facial expression of an image while ignoring an overlaid congruent or incongruent affect label. Participants then completed two weeks of ambulatory assessment of daily-life emotion dysregulation. Consistent with previous research on comorbid emotional distress disorders (Etkin and Schatzberg, 2011), there was no behavioral effect of emotional conflict adaptation (p = .701) but a significant effect of congruent adaptation (p = .006), suggesting impairment is specific to implicit emotional conflict regulation. Additionally, there was no neural evidence of emotional conflict adaptation in the ventral ACC and amygdala (ps > .766). Further, in our primary psychophysiological interactions analyses, we examined ventral ACC-amygdala functional connectivity. As hypothesized, increased ventral ACC-amygdala functional connectivity for emotional conflict adaptation was associated with increased daily-life affective instability (p = .022), but not mean daily-life negative affect (p = .372). Overall, results provide behavioral and neural evidence of impaired implicit emotional conflict adaptation in individuals with emotional distress disorders and suggests that this impairment is related to daily-life affective instability in these disorders.

Inhibition of emotions in healthy aging: age-related differences in brain network connectivity

INTRODUCTION

Successful inhibition of distracting emotions is important for preserving well-being and daily functioning. There is conflicting evidence regarding the impact of healthy aging on emotional inhibition, and possible age-related alterations in the neuronal underpinnings of emotional interference processing are unexplored.

METHODS

Thirty younger (mean age 26 years; 15 women) and 30 older (mean age 71 years; 13 women) healthy adults performed a face-word emotional Stroop task while undergoing functional magnetic resonance imaging of the brain. A resting-state scan was acquired for calculating the amplitude of low-frequency fluctuations as an estimate of vascular reactivity. Comparisons of brain activation during the task were assessed in a whole-brain, voxel-wise analysis, contrasting congruent, and incongruent conditions. The canonical regions of the frontoparietal, salience, dorsal attention, and default mode networks were used as seed regions for assessing functional connectivity within and between large-scale brain networks. Task performance was evaluated using response accuracy and response time.

RESULTS

The older adults had longer response times and lower task accuracy than the younger adults, but the emotional interference effect was not significantly different between the groups. Whole-brain analysis revealed no significant age-related differences in brain activation patterns. Rescaling the data for estimated variability in vascular reactivity did not affect the results. In older adults, there was relatively stronger functional connectivity with the default mode network, the sensorimotor network, and the dorsal attention network for the frontoparietal and salience network seeds during the task. Conversely, younger adults had relatively stronger connections within and between the frontoparietal and salience networks.

CONCLUSION

In this first fMRI study of emotional Stroop interference in older and younger adults, we found that the emotional interference effect was unchanged in healthy aging and replicated the finding from non-emotional task studies that older adults have greater between-network and less within-network connectivity compared to younger adults.

Rumination in major depressive and bipolar disorder - a meta-analysis

BACKGROUND

rumination, defined as repetitive thoughts about emotionally relevant experiences, has been linked extensively with mood disorders, especially major depressive disorder (MDD).¹ However, there is a growing body of evidence suggesting the importance of rumination in bipolar disorder (BD)² as well.

METHODS

we searched for studies that investigated rumination in both BD and MDD in four databases. Our systematic search identified 12 studies with an overall sample size of 2071 clinical patients.

RESULTS

results demonstrated no significant difference in the ruminative tendencies of the two patient groups when all rumination measures were included. We tested for the effect of rumination subtype, BD subgroups, and the current mood state of BD and MDD patients. There were no significant differences in terms of depressive rumination, however, BD patients reported more rumination on positive affect. This difference remained significant when examining in BD-I³ and BD-II⁴ patient groups, with similar effect sizes.

LIMITATIONS

due to the lack of sufficient data in the literature, only a few self-report studies qualified to be included in our analysis. Thus additional moderating factors, such as the current mood state of the two patient groups could not be analyzed.

CONCLUSIONS

this review demonstrates that rumination is a significant process in both MDD and BD, highlighting the importance of interventions to reduce rumination in mood disorders. The two patient groups share several commonalities in terms of rumination, however, rumination subtype was found to be an important moderating variable underlining a difference in rumination on positive affect.

Disturbances of Dynamic Function in Patients With Bipolar Disorder I and Its Relationship With Executive-Function Deficit

Abnormity in brain regional function and inter-regional cooperation have been linked with the dysfunction during cognitive and emotional processing in bipolar disorder (BD) patients. Recent evidences have suggested that brain function is not static but temporal dynamic. In present study, we aimed to characterize the temporal dynamics of regional function and inter-regional cooperation in BD and its relationship with executive dysfunction, an important deficit in BD. Resting-state functional MRI was performed in patients with bipolar I disorder (BDI) (n = 18) and healthy controls (HCs, n = 19). We first assessed local-function temporal variety with dynamic amplitude of low-frequency fluctuation (dALFF). Region with significant inter-groups difference in dALFF was chosen as a seed to calculate inter-regions connective temporal variety with dynamic functional connectivity (dFC). The executive function was measured by Verbal Fluency Test (VFT). The relationship between executive function and brain dynamics were examined. Compared with HC, the BDI group showed decreased dALFF (less temporal variability) in the posterior cingulate cortex (PCC) and decreased dFC between PCC and medial prefrontal cortex (mPFC). The PCC-mPFC dFC was positively associated with VFT in BDI patients, but not in HC. These findings implicated the reduced temporal variability in local region and inter-regions cooperation in BDI, which may be a neural substrate of executive-function deficit in BDI.

Resting-state functional connectivity of emotion regulation networks in euthymic and non-euthymic bipolar disorder patients

Background

Previous functional magnetic resonance imaging studies in bipolar disorder (BD) have evidenced changes in functional connectivity (FC) in brain areas associated with emotion processing, but how these changes vary with mood state and specific clinical symptoms is not fully understood.

Methods

We investigated resting-state FC between a priori regions of interest (ROIs) from the default-mode network and key structures for emotion processing and regulation in 27 BD patients and 27 matched healthy controls. We further compared connectivity patterns in subgroups of 15 euthymic and 12 non-euthymic patients and tested for correlations of the connectivity strength with measures of mood, anxiety, and rumination tendency. No correction for multiple comparisons was applied given the small population sample and pre-defined target ROIs.

Results

Overall, regardless of mood state, BD patients exhibited increased FC of the left amygdala with left sgACC and PCC, relative to controls. In addition, non-euthymic BD patients showed distinctive decrease in FC between right amygdala and sgACC, whereas euthymic patients showed lower FC between PCC and sgACC. Euthymic patients also displayed increased FC between sgACC and right VLPFC. The sgACC–PCC and sgACC–left amygdala connections were modulated by rumination tendency in non-euthymic patients, whereas the sgACC-VLPFC connection was modulated by both the current mood and tendency to ruminate.

Conclusions

Our results suggest that sgACC-amygdala coupling is critically affected during mood episodes, and that FC of sgACC play a pivotal role in mood normalization through its interactions with the VLPFC and PCC. However, these preliminary findings require replication with larger samples of patients.

Escitalopram ameliorates differences in neural activity between healthy comparison and major depressive disorder groups on an fMRI Emotional conflict task: A CAN-BIND-1 study

BACKGROUND

Identifying objective biomarkers can assist in predicting remission/non-remission to treatment, improving remission rates, and reducing illness burden in major depressive disorder (MDD).

METHODS

Sixteen MDD 8-week remitters (MDD-8), twelve 16-week remitters (MDD-16), 14 non-remitters (MDD-NR) and 30 healthy comparison participants (HC) completed a functional magnetic resonance imaging emotional conflict task at baseline, prior to treatment with escitalopram, and 8 weeks after treatment initiation. Patients were followed 16 weeks to assess remitter status.

RESULTS

All groups demonstrated emotional Stroop in reaction time (RT) at baseline and Week 8. There were no baseline differences between HC and MDD-8, MDD-16, or MDD-NR in RT or accuracy. By Week 8, MDD-8 demonstrated poorer accuracy compared to HC. Compared to HC, the baseline blood-oxygen level dependent (BOLD) signal was decreased in MDD-8 in brain-stem and thalamus; in MDD-16 in lateral occipital cortex, middle temporal gyrus, and cuneal cortex; in MDD-NR in lingual and occipital fusiform gyri, thalamus, putamen, caudate, cingulate gyrus, insula, cuneal cortex, and middle temporal gyrus. By Week 8, there were no BOLD activity differences between MDD groups and HC.

LIMITATIONS

The Emotional Conflict Task lacks a neutral (non-emotional) condition, restricting interpretation of how mood may influence perception of non-emotionally valenced stimuli.

CONCLUSIONS

The Emotional Conflict Task is not an objective biomarker for remission trajectory in patients with MDD receiving escitalopram treatment. Escitalopram may have influenced emotion recognition in MDD groups in terms of augmented accuracy and BOLD signal in response to an Emotional Conflict Task, following 8 weeks of escitalopram treatment.

Reduced accuracy accompanied by reduced neural activity during the performance of an emotional conflict task by unmedicated patients with major depression: A CAN-BIND fMRI study

METHODS

We studied 48 MDD and 30 HC who performed an emotional conflict task in a functional magnetic resonance imaging (fMRI) scanner.

RESULTS

On the emotional conflict task, MDD and HC demonstrated a robust emotional Stroop effect in reaction time and accuracy. Overall, accuracy was lower in MDD compared to HC with no significant reaction time differences. The fMRI data indicated lower BOLD activation in MDD compared to HC on comparisons of all trials, congruent, incongruent, and incongruent > congruent trials in regions including right inferior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus. Behavioural and neuroimaging data indicated no group differences in fearful versus happy face processing.

LIMITATIONS

Inclusion of a neutral condition may have provided a valuable contrast to how MDD and HC process stimuli without emotional valence compared to stimuli with a strong emotional valence.

CONCLUSIONS

MDD and HC demonstrated a robust emotional Stroop effect. Compared to HC, MDD demonstrated an overall reduced accuracy on the emotional conflict task and reduced BOLD activity in regions important for face perception and emotion information processing, with no differences in responding to fearful versus happy faces. These findings provide support for the theory of emotion context insensitivity in individuals with depression.

Longitudinal brain functional changes between mania and euthymia in bipolar disorder

OBJECTIVES

While widespread cortical and subcortical brain functional abnormalities have been found in bipolar disorder, the changes that take place between illness phases and recovery are less clearly documented. Only a small number of longitudinal studies of manic patients, in particular, have been carried out.

METHODS

Twenty-six bipolar patients underwent fMRI during performance of the n-back working memory task when manic and again after recovery. Twenty-six matched healthy controls were also scanned on two occasions. Task-related activations and de-activations were examined.

RESULTS

When manic, the patients showed clusters of significantly reduced activation in the left dorsolateral prefrontal cortex (DLPFC)/precentral cortex and the parietal cortex/superior precuneus bilaterally. They also showed failure of de-activation in the ventromedial frontal cortex (vmPFC). After recovery, activation in the left DLPFC/precentral cortex and in the bilateral parietal cortex/superior precuneus clusters increased significantly. However, failure of de-activation remained present in the vmPFC.

CONCLUSIONS

Recovery from mania is associated with normalization of DLPFC and parietal hypoactivation, but not with vmPFC failure of de-activation, which accordingly appears to represent a trait abnormality in the disorder.

Correlation between Intrinsic Brain Activity and Thyroid-Stimulating Hormone Level in Unmedicated Bipolar II Depression

BACKGROUND/AIMS

Although abnormalities of amplitude of low-frequency fluctuations (ALFF) and hormone levels of hypothalamus-pituitary-thyroid axis have been reported in patients with bipolar disorder (BD), the association between abnormal ALFF and serum thyroid hormone levels remains unknown.

METHOD

A total of 90 patients with unmedicated BD II depression and 100 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging, and then routine band (0.01-0.1 Hz), slow-5 band (0.01-0.027 Hz), and slow-4 band (0.027-0.073 Hz) ALFF analysis were performed. Additionally, serum thyroid hormone levels including free tri-iodothyronine (FT3), total tri-iodothyronine (TT3), free thyroxin (FT4), total thyroxin (TT4), and thyroid-stimulating hormone (TSH) were detected. The correlation between abnormal serum thyroid hormone levels and ALFF values in patients with BD II depression was calculated.

RESULTS

Compared with the HCs, patients with BD II depression showed decreased ALFF in bilateral precuneus (PCu)/posterior cingulate cortex (PCC) in routine and slow-4 frequency bands, decreased ALFF in the right PCu, and increased ALFF in the right middle occipital gyrus (MOG) in the slow-5 frequency band. Additionally, patients with BD II depression showed lower TSH level than HCs, and TSH level was positively correlated with ALFF values in the bilateral PCu/PCC in the routine frequency band.

CONCLUSIONS

These findings suggest that patients with BD II depression display intrinsic activity abnormalities, mainly in the PCu/PCC and MOG, which are associated with specific frequency bands. Moreover, altered intrinsic activity in the PCu/PCC may be related to TSH levels in bipolar II depression.

Volumetric MRI Analysis of a Case of Severe Ventriculomegaly

We present a case of a 60-year-old male referred to a tertiary psychiatric facility for diagnostic assessment due to low mood and behavioral changes. Neurological examination of the patient was unremarkable. Magnetic resonance imaging (MRI) indicated overt ventriculomegaly with gross dilatation of lateral and third ventricles. Manual segmentation of gray matter, white matter and cerebrospinal fluid demonstrated that the patient had a ventricular volume almost 46 times greater than that of healthy volunteers in the same age range. Despite his striking degree of ventriculomegaly and cortical thinning, he presented primarily with psychiatric and cognitive complaints. These represented a major neurocognitive disorder. His behavior improved with a structured environment and routine instituted by the treating team. This is a dramatic example of the brain's response to extreme structural remodeling. Elements of pluripotentiality may counteract degeneracy to preserve functions in cases of serious structural stress in the brain. Changes in the neural circuitry of emotional processing, and/or disruption in signaling pathways important for synaptogenesis may influence depression pathophysiology. How this circuitry is modified in cases of extreme structural stress such as long-standing overt ventriculomegaly, is unclear. This case demonstrates the ability of the brain to generate a normal phenotype despite structural changes that seem incompatible with advanced cognitive function, illustrating the substantial potential for adaptability and plasticity in the brain.

A domain-general brain network underlying emotional and cognitive interference processing: evidence from coordinate-based and functional connectivity meta-analyses

The inability to control or inhibit emotional distractors characterizes a range of psychiatric disorders. Despite the use of a variety of task paradigms to determine the mechanisms underlying the control of emotional interference, a precise characterization of the brain regions and networks that support emotional interference processing remains elusive. Here, we performed coordinate-based and functional connectivity meta-analyses to determine the brain networks underlying emotional interference. Paradigms addressing interference processing in the cognitive or emotional domain were included in the meta-analyses, particularly the Stroop, Flanker, and Simon tasks. Our results revealed a consistent involvement of the bilateral dorsal anterior cingulate cortex, anterior insula, left inferior frontal gyrus, and superior parietal lobule during emotional interference. Follow-up conjunction analyses identified correspondence in these regions between emotional and cognitive interference processing. Finally, the patterns of functional connectivity of these regions were examined using resting-state functional connectivity and meta-analytic connectivity modeling. These regions were strongly connected as a distributed system, primarily mapping onto fronto-parietal control, ventral attention, and dorsal attention networks. Together, the present findings indicate that a domain-general neural system is engaged across multiple types of interference processing and that regulating emotional and cognitive interference depends on interactions between large-scale distributed brain networks.

Orbital and Medial Prefrontal Cortex Functional Connectivity of Major Depression Vulnerability and Disease

BACKGROUND

Pathophysiology models of major depression (MD) center on the dysfunction of various cortical areas within the orbital and medial prefrontal cortex. While independent structural and functional abnormalities in these areas are consistent findings in MD, the complex interactions among them and the rest of the cortex remain largely unexplored.

METHODS

We used resting-state functional magnetic resonance imaging connectivity to systematically map alterations in the communication between orbital and medial prefrontal cortex fields and the rest of the brain in MD. Functional connectivity (FC) maps from participants with current MD (n = 35), unaffected first-degree relatives (n = 36), and healthy control subjects (n = 38) were subjected to conjunction analyses to distinguish FC markers of MD vulnerability and FC markers of MD disease.

RESULTS

FC abnormalities in MD vulnerability were found for dorsal medial wall regions and the anterior insula and concerned altered communication of these areas with the inferior parietal cortex and dorsal posterior cingulate, occipital areas and the brainstem. FC aberrations in current MD included the anterior insula, rostral and dorsal anterior cingulate cortex, and lateral orbitofrontal areas and concerned altered communication with the dorsal striatum, the cerebellum, the precuneus, the anterior prefrontal cortex, somatomotor cortex, dorsolateral prefrontal cortex, and visual areas in the occipital and inferior temporal lobes.

CONCLUSIONS

Functionally delineated parcellation maps can be used to identify putative connectivity markers in extended cortical regions such as the orbital and medial prefrontal cortex. The anterior insula and the rostral anterior cingulate cortex play a central role in the pathophysiology of MD, being consistently implicated both in the MD vulnerability and MD disease states.

Relationship of executive functioning deficits to N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) in youth with bipolar disorder

BACKGROUND

Although cognitive deficits in bipolar disorder (BD) have been repeatedly observed, our understanding of these impairments at a mechanistic level remains limited. Few studies that investigated cognitive impairments in bipolar illness have examined the association with brain biochemistry. This pilot study utilized proton magnetic resonance spectroscopy (¹H-MRS) to evaluate the relationship between neurocognitive performance and brain metabolites in youth with BD.

METHODS

Thirty participants, twenty depressed BD participants and ten healthy comparison participants, ages 13-21, completed mood and executive function measures. ¹H-MRS data were also acquired from the anterior cingulate cortex (ACC) using two-dimensional (2D) J-resolved ¹H-MRS sequence. Proton metabolites including N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) were quantified for both groups.

RESULTS

Participants with BD performed significantly lower on executive functioning measures than comparison participants. There were significant positive correlations between Wisconsin Card Sorting Test (WCST) performance and NAA (p < .001) and GABA (p < .01) in the ACC in bipolar youth, such that as WCST performance increased, both NAA and GABA levels increased.

LIMITATIONS

Small sample size and lack of control for medications.

CONCLUSIONS

These findings build on previous observations of biochemical alterations associated with BD and indicate that executive functioning deficits in bipolar youth are correlated with NAA and GABA. These results suggest that cognitive deficits occur early in the course of illness and may reflect risk factors associated with altered neurochemistry. Further investigation of the relationship between brain metabolites and cognition in BD may lead to important information for developing novel, targeted interventions.

Meta-analysis of regional white matter volume in bipolar disorder with replication in an independent sample using coordinates, T-maps, and individual MRI data

Converging evidence suggests that bipolar disorder (BD) is associated with white matter (WM) abnormalities. Meta-analyses of voxel based morphometry (VBM) data is commonly performed using published coordinates, however this method is limited since it ignores non-significant data. Obtaining statistical maps from studies (T-maps) as well as raw MRI datasets increases accuracy and allows for a comprehensive analysis of clinical variables. We obtained coordinate data (7-studies), T-Maps (12-studies, including unpublished data) and raw MRI datasets (5-studies) and analysed the 24 studies using Seed-based d Mapping (SDM). A VBM analysis was conducted to verify the results in an independent sample. The meta-analysis revealed decreased WM volume in the posterior corpus callosum extending to WM in the posterior cingulate cortex. This region was significantly reduced in volume in BD patients in the independent dataset (p=0.003) but there was no association with clinical variables. We identified a robust WM volume abnormality in BD patients that may represent a trait marker of the disease and used a novel methodology to validate the findings.

Meta-analysis of functional magnetic resonance imaging studies of timing and cognitive control in schizophrenia and bipolar disorder: Evidence of a primary time deficit

Schizophrenia (SZ) and Bipolar Disorder (BD) are associated with deficits in both timing and cognitive control functions. However, the underlying neurological dysfunctions remain poorly understood. The main goal of this study was to identify brain structures activated both by increases in cognitive activity and during timing tasks in patients with SZ and BD relative to controls. We conducted two signed differential mapping (SDM) meta-analyses of functional magnetic resonance imaging studies assessing the brain response to increasing levels of cognitive difficulty: one concerned SZ, and the other BD patients. We conducted a similar SDM meta-analysis on neuroimaging of timing in SZ (no studies in BD could be included). Finally, we carried out a multimodal meta-analysis to identify common brain regions in the findings of the two previous meta-analyses. We found that SZ patients showed hypoactivation in timing-related cortical-subcortical areas. The dysfunction observed during timing partially coincided with deficits for cognitive control functions. We hypothesize that a dysfunctional temporal/cognitive control network underlies the persistent cognitive impairment observed in SZ.

The influence of emotional interference on cognitive control: A meta-analysis of neuroimaging studies using the emotional Stroop task

The neural correlates underlying the influence of emotional interference on cognitive control remain a topic of discussion. Here, we assessed 16 neuroimaging studies that used an emotional Stroop task and that reported a significant interaction effect between emotion (stimulus type) and cognitive conflict. There were a total of 330 participants, equaling 132 foci for an activation likelihood estimation (ALE) analysis. Results revealed consistent brain activation patterns related to emotionally-salient stimuli (as compared to emotionally-neutral trials) during cognitive conflict trials [incongruent trials (with task-irrelevant information interfering), versus congruent/baseline trials (less disturbance from task-irrelevant information)], that span the lateral prefrontal cortex (dorsolateral prefrontal cortex and inferior frontal gyrus), the medial prefrontal cortex, and the dorsal anterior cingulate cortex. Comparing mild emotional interference trials (without semantic conflict) versus intense emotional interference trials (with semantic conflict), revealed that while concurrent activation in similar brain regions as mentioned above was found for intense emotional interference trials, activation for mild emotional interference trials was only found in the precentral/postcentral gyrus. These data provide evidence for the potential neural mechanisms underlying emotional interference on cognitive control, and further elucidate an important distinction in brain activation patterns for different levels of emotional conflict across emotional Stroop tasks.

Neural Systems Underlying Emotional and Non-emotional Interference Processing: An ALE Meta-Analysis of Functional Neuroimaging Studies

Understanding how the nature of interference might influence the recruitments of the neural systems is considered as the key to understanding cognitive control. Although, interference processing in the emotional domain has recently attracted great interest, the question of whether there are separable neural patterns for emotional and non-emotional interference processing remains open. Here, we performed an activation likelihood estimation meta-analysis of 78 neuroimaging experiments, and examined common and distinct neural systems for emotional and non-emotional interference processing. We examined brain activation in three domains of interference processing: emotional verbal interference in the face-word conflict task, non-emotional verbal interference in the color-word Stroop task, and non-emotional spatial interference in the Simon, SRC and Flanker tasks. Our results show that the dorsal anterior cingulate cortex (ACC) was recruited for both emotional and non-emotional interference. In addition, the right anterior insula, presupplementary motor area (pre-SMA), and right inferior frontal gyrus (IFG) were activated by interference processing across both emotional and non-emotional domains. In light of these results, we propose that the anterior insular cortex may serve to integrate information from different dimensions and work together with the dorsal ACC to detect and monitor conflicts, whereas pre-SMA and right IFG may be recruited to inhibit inappropriate responses. In contrast, the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC) showed different degrees of activation and distinct lateralization patterns for different processing domains, which suggests that these regions may implement cognitive control based on the specific task requirements.

Distinguishing medication-free subjects with unipolar disorder from subjects with bipolar disorder: state matters

OBJECTIVES

Recent studies have indicated that pattern recognition techniques of functional magnetic resonance imaging (fMRI) data for individual classification may be valuable for distinguishing between major depressive disorder (MDD) and bipolar disorder (BD). Importantly, medication may have affected previous classification results as subjects with MDD and BD use different classes of medication. Furthermore, almost all studies have investigated only depressed subjects. Therefore, we focused on medication-free subjects. We additionally investigated whether classification would be mood state independent by including depressed and remitted subjects alike.

METHODS

We applied Gaussian process classifiers to investigate the discriminatory power of structural MRI (gray matter volumes of emotion regulation areas) and resting-state fMRI (resting-state networks implicated in mood disorders: default mode network [DMN], salience network [SN], and lateralized frontoparietal networks [FPNs]) in depressed (n=42) and remitted (n=49) medication-free subjects with MDD and BD.

RESULTS

Depressed subjects with MDD and BD could be classified based on the gray matter volumes of emotion regulation areas as well as DMN functional connectivity with 69.1% prediction accuracy. Prediction accuracy using the FPNs and SN did not exceed chance level. It was not possible to discriminate between remitted subjects with MDD and BD.

CONCLUSIONS

For the first time, we showed that medication-free subjects with MDD and BD can be differentiated based on structural MRI as well as resting-state functional connectivity. Importantly, the results indicated that research concerning diagnostic neuroimaging tools distinguishing between MDD and BD should consider mood state as only depressed subjects with MDD and BD could be correctly classified. Future studies, in larger samples are needed to investigate whether the results can be generalized to medication-naïve or first-episode subjects.

The neural networks of subjectively evaluated emotional conflicts

Previous work on the neural underpinnings of emotional conflict processing has largely focused on designs that instruct participants to ignore a distracter which conflicts with a target. In contrast, this study investigated the noninstructed experience and evaluation of an emotional conflict, where positive or negative cues can be subjectively prioritized. To this end, healthy participants freely watched short film scenes that evoked emotional conflicts while their BOLD responses were measured. Participants' individual ratings of conflict and valence perception during the film scenes were collected immediately afterwards, and the individual ratings were regressed against the BOLD data. Our analyses revealed that (a) amygdala and medial prefrontal cortex were significantly involved in prioritizing positive or negative cues, but not in subjective evaluations of conflict per se, and (b) superior temporal sulcus (STS) and inferior parietal lobule (IPL), which have been implicated in social cognition and emotion control, were involved in both prioritizing positive or negative cues and subjectively evaluating conflict, and may thus constitute "hubs" or "switches" in emotional conflict processing. Psychophysiological interaction (PPI) analyses further revealed stronger functional connectivity between IPL and ventral prefrontal-medial parietal areas in prioritizing negative cues, and stronger connectivity between STS and dorsal-rostral prefrontal-medial parietal areas in prioritizing positive cues. In sum, our results suggest that IPL and STS are important in the subjective evaluation of complex conflicts and influence valence prioritization via prefrontal and parietal control centers. Hum Brain Mapp 37:2234-2246, 2016. © 2016 Wiley Periodicals, Inc.

Neuropsychological underpinnings of the dynamics of bipolar disorder

Although we have gained enormous insights into neurobiological and psychological underpinnings of bipolar disorder (BD) symptoms, our knowledge concerning pathogenic mechanisms initiating recurrent affective episodes is still fragmentary. Previous research has highlighted the role of significant life events and social rhythm in recurrent episodes of mania and depression. However, most studies share the drawback of retrospective self-report data, which are prone to recall biases and limited introspective abilities. Therefore, more objective data, such as neuropsychological and neurobiological measures are needed to further unravel the pathogenic mechanisms of the dynamics of bipolar disorder. Previous research has highlighted disturbed emotional reactivity as well as impaired emotion regulation and impulse control as major behavioural characteristics of BD and aberrancies in prefrontal-limbic-striatal networks that have been proposed to be the correlates of these behavioural alterations. However, longitudinal studies assessing these neural and behavioural alterations are rare. Future research should therefore adopt prospective study designs including behavioural and neuroimaging measures underlying cognitive, emotional and motivational deficits in bipolar disorder. Particularly, these measures should be collected continuously at multiple time points as implemented in modern ambulatory assessment tools.

The role of negative mood induction on working memory capacity in individuals putatively at risk for bipolar disorder: A pilot study

OBJECTIVE

Bipolar disorder (BD) is characterized by cognitive deficits. Usually individuals at risk for BD do not exhibit such deficits but they might be evident under cognitive or emotionally stressful conditions. To our knowledge this is the first study examining working memory capacity under mood induction in individuals at risk for BD.

METHODS

Using the Hypomanic Personality Scale (HPS) 68 participants out of an initial pool of 148 students were divided into groups at high and low risk for BD. They completed twice a Dual Task Paradigm (DTP) task assessed under high and low cognitive load prior to and following a negative mood induction.

RESULTS

As expected stimuli incongruency, high cognitive load and mood induction increased response times. Contrary to our hypothesis the mood induction did not differentially affect at-risk individuals. However, they generally reacted faster to neutral stimuli compared to those at low risk.

CONCLUSIONS

While we replicated former results related to the DTP, we did not find evidence for the hypothesis that individuals putatively at risk for BD will be more affected by negative mood when doing such a cognitive task. Replication using a larger sample is needed which should also examine whether changes in positive mood might more relevant in the context of risk for mania.

Cerebral Correlates of Abnormal Emotion Conflict Processing in Euthymic Bipolar Patients: A Functional MRI Study

BACKGROUND

Patients with bipolar disorder experience cognitive and emotional impairment that may persist even during the euthymic state of the disease. These persistent symptoms in bipolar patients (BP) may be characterized by disturbances of emotion regulation and related fronto-limbic brain circuitry. The present study aims to investigate the modulation of fronto-limbic activity and connectivity in BP by the processing of emotional conflict.

METHODS

Fourteen euthymic BP and 13 matched healthy subjects (HS) underwent functional magnetic resonance imaging (fMRI) while performing a word-face emotional Stroop task designed to dissociate the monitoring/generation of emotional conflict from its resolution. Functional connectivity was determined by means of psychophysiological interaction (PPI) approach.

RESULTS

Relative to HS, BP were slower to process incongruent stimuli, reflecting higher amount of behavioral interference during emotional Stroop. Furthermore, BP showed decreased activation of the right dorsolateral prefrontal cortex (DLPFC) during the monitoring and a lack of bilateral amygdala deactivation during the resolution of the emotional conflict. In addition, during conflict monitoring, BP showed abnormal positive connectivity between the right DLPFC and several regions of the default mode network.

CONCLUSIONS

Overall, our results highlighted dysfunctional processing of the emotion conflict in euthymic BP that may be subtended by abnormal activity and connectivity of the DLPFC during the conflict monitoring, which, in turn, leads to failure of amygdala deactivation during the resolution of the conflict. Emotional dysregulation in BP may be underpinned by a lack of top-down cognitive control and a difficulty to focus on the task due to persistent self-oriented attention.

Recent Advances in Laboratory Assessment of Emotion Regulation

Over the past 15 years, the emotion regulation perspective has been widely integrated into theoretical and applied contexts in clinical psychology and beyond. Recent refinements to behavioral, subjective, psychophysiological and neuroimaging methods allow emotion regulation to be captured and assessed in the laboratory with greater precision. Technological advances enabling investigators to leverage information from multiple modalities are increasingly accessible, and as such, will further efforts to generate testable hypotheses about specific mechanisms implicated in emotion regulation and difficulties therein. In combination with theory-driven design, progressively sophisticated methods for laboratory assessment have potential to further emotion regulation as both a valid scientific construct and a useful paradigm for human emotion and behavior that has applicability to both clinical and non-clinical contexts.

Functional connectivity mapping of regions associated with self- and other-processing

Neuroscience literature increasingly suggests a conceptual self composed of interacting neural regions, rather than independent local activations, yet such claims have yet to be investigated. We, thus, combined task-dependent meta-analytic connectivity modeling (MACM) with task-independent resting-state (RS) connectivity analysis to delineate the neural network of the self, across both states. Given psychological evidence implicating the self's interdependence on social information, we also delineated the neural network underlying conceptual other-processing. To elucidate the relation between the self-/other-networks and their function, we mined the MACM metadata to generate a cognitive-behavioral profile for an empirically identified region specific to conceptual self, the pregenual anterior cingulate (pACC), and conceptual other, posterior cingulate/precuneus (PCC/PC). Mining of 7,200 published, task-dependent, neuroimaging studies, using healthy human subjects, yielded 193 studies activating the self-related seed and were conjoined with RS connectivity analysis to delineate a differentiated self-network composed of the pACC (seed) and anterior insula, relative to other functional connectivity. Additionally, 106 studies activating the other-related seed were conjoined with RS connectivity analysis to delineate a differentiated other-network of PCC/PC (seed) and angular gyrus/temporoparietal junction, relative to self-functional connectivity. The self-network seed related to emotional conflict resolution and motivational processing, whereas the other-network seed related to socially oriented processing and contextual information integration. Notably, our findings revealed shared RS connectivity between ensuing self-/other-networks within the ventromedial prefrontal cortex and medial orbitofrontal cortex, suggesting self-updating via integration of self-relevant social information. We, therefore, present initial neurobiological evidence corroborating the increasing claims of an intricate self-network, the architecture of which may promote social value processing.

Dissociable patterns in the control of emotional interference in adults with attention-deficit/hyperactivity disorder (ADHD) and in adults with alcohol dependence

Objectives

To effectively manage current task demands, attention must be focused on task-relevant information while task-irrelevant information is rejected. However, in everyday life, people must cope with emotions, which may interfere with actual task demands and may challenge functional attention allocation. Control of interfering emotions has been associated with the proper functioning of the dorsolateral prefrontal cortex (DLPFC). As DLPFC dysfunction is evident in subjects with ADHD and in subjects with alcohol dependence, the current study sought to examine the bottom-up effect of emotional distraction on task performance in both disorders.

Methods

Male adults with ADHD (n = 22), male adults with alcohol dependence (n = 16), and healthy controls (n = 30) performed an emotional working memory task (n-back task). In the background of the task, we presented neutral and negative stimuli that varied in emotional saliency.

Results

In both clinical groups, a working memory deficit was evident. Moreover, both clinical groups displayed deficient emotional interference control. The n-back performance of the controls was not affected by the emotional distractors, whereas that of subjects with ADHD deteriorated in the presence of low salient distractors, and that of alcoholics did not deteriorate until high salient distractors were presented. Subsequent to task performance, subjects with ADHD accurately recognized more distractors than did alcoholics and controls. In alcoholics, picture recognition accuracy was negatively associated with n-back performance, suggesting a functional association between the ability to suppress emotional distractors and successful task performance. In subjects with ADHD, performance accuracy was negatively associated with ADHD inattentive symptoms, suggesting that inattention contributes to the performance deficit.

Conclusions

Subjects with ADHD and alcoholics both display an emotional interference control deficit, which is especially pronounced in subjects with ADHD. Beyond dysfunctional attention allocation processes, a more general attention deficit seems to contribute to the more pronounced performance deficit pattern in ADHD.