Exaggerated neural response to emotional faces in patients with bipolar disorder and their first-degree relatives

Common and distinct neural correlates of emotional processing in individuals at familial risk for major depressive disorder and bipolar disorder: A comparative meta-analysis

Individuals at familial risk for mood disorders exhibit deficits in emotional processing and associated brain dysfunction prior to illness onset. However, such brain-behavior abnormalities related to familial predisposition remain poorly understood. To investigate robust abnormal functional activation patterns during emotional processing in unaffected at-risk relatives of patients with major depressive disorder (UAR-MDD) and bipolar disorder (UAR-BD), we performed a meta-analysis of task-based functional magnetic resonance imaging studies using Seed-based d Mapping (SDM) toolbox. Common and distinct patterns of abnormal functional activation between UAR-MDD and UAR-BD were detected via conjunction and differential analyses. A total of 17 studies comparing 481 UAR and 670 healthy controls (HC) were included. Compared with HC, UAR-MDD exhibited hyperactivation in the parahippocampal gyrus, amygdala and cerebellum, while UAR-BD exhibited parahippocampal hyperactivation and hypoactivation in the striatum and middle occipital gyrus (MOG). Conjunction analysis revealed shared hyperactivated PHG in both groups. Differential analysis indicated that the activation patterns of amygdala and MOG significantly differed between UAR-MDD and UAR-BD. These findings provide novel insights into common and distinct neural phenotypes for familial risk and associated risk mechanisms in MDD and BD, which may have implications in guiding precise prevention strategies tailored to the family context.

Distinct functional patterns in child and adolescent bipolar and unipolar depression during emotional processing

Accumulating evidence from functional magnetic resonance imaging studies supported brain dysfunction during emotional processing in bipolar disorder (BD) and major depressive disorder (MDD). However, child and adolescent BD and MDD could display different activation patterns, which have not been fully understood. This study aimed to investigate common and distinct activation patterns of pediatric BD (PBD) and MDD (p-MDD) during emotion processing using meta-analytic approaches. Literature search identified 25 studies, contrasting 252 PBD patients, and 253 healthy controls (HCs) as well as 311 p-MDD patients and 263 HCs. A total of nine meta-analyses were conducted pulling PBD and p-MDD experiments together and separately. The results revealed that PBD and p-MDD showed distinct patterns during negative processing. PBD patients exhibited activity changes in bilateral precuneus, left inferior parietal gyrus, left angular gyrus, and right posterior cingulate cortex while p-MDD patients showed functional disruptions in the left rectus, left triangular part of the inferior frontal gyrus, left orbital frontal cortex, left insula, and left putamen. In conclusion, the activity changes in PBD patients were mainly in regions correlated with emotion perception while the dysfunction among p-MDD patients was in the fronto-limbic circuit and reward-related regions in charge of emotion appraisal and regulation.

How do bipolar disease states affect positive and negative emotion processing? Insights from a meta-analysis on the neural fingerprints of emotional processing

BACKGROUND

Functional magnetic resonance imaging studies on emotion processing in patients with bipolar disorder (BD) show hyperactivity of limbic-striatal brain areas and hypoactivity in inferior frontal areas compared to healthy participants. However, heterogeneous results in patients with different disease states and different valences of emotional stimuli have been identified.

METHODS

To integrate previous results and elucidate the impact of disease state and stimulus valence, we conducted a systematic literature search for journal articles in the Web of Science Core Collection including MEDLINE databases and employed a coordinate-based-meta-analysis of functional-MRI studies comparing emotion processing in BD-patients with healthy participants using seed-based d mapping (SDM) to test for between-subjects-effects. We included 31 studies published before 11/2022 with a total of N = 766 BD-patients and N = 836 controls.

RESULTS

Patients with BD showed hyperactivated regions involved in salience processing of emotional stimuli (e.g., the bilateral insula) and hypoactivation of regions associated with emotion regulation (e.g., inferior frontal gyrus) during emotion processing, compared to healthy participants. A more detailed descriptive analysis revealed a hypoactive (anterior) insula in manic BD-patients specifically for negative in comparison to positive emotion processing.

DISCUSSION

This meta-analysis corroborates the overall tenor of existing literature that patients with BD show an increased emotional reactivity (hyperactivity of salience-processing regions) together with a lower (cognitive) control (hypoactivity of brain areas associated with emotion regulation) over emotional states. Our analysis suggests reduced interoceptive processing of negative stimuli in mania, pointing out the need for longitudinal within-subject analyses of emotion processing.

Effect of high-definition transcranial direct current stimulation on improving depression and modulating functional activity in emotion-related cortical-subcortical regions in bipolar depression

Preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for bipolar depression, However, brain correlates of the depression alleviating are unclear. To determine the efficacy and safety of tDCS as an add-on treatment for patients with bipolar depression and further to identify the effect of tDCS on the resting-state brain activities, we recruited fifty patients with bipolar depression to complete the double-blind, sham-controlled and randomized clinical trial. Fourteen sessions of tDCS were performed once a day for 14 days. The anode was placed over F3 with return electrodes placed at FP1, FZ, C3 and F7. Regional homogeneity (ReHo) was examined on 50 patients with bipolar depression before and after 14-day active or sham tDCS. Patients in the active group showed significantly superior alleviating the depression symptoms compared with those receiving sham. The active group after 14-day active tDCS showed increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and decreased ReHo values in subcortical structures including hippocampus, parahippocampa gyrus, amygdala, putamen and lentiform nucleus. The reduction of depression severity showed positive correlation of increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and negative correlation of altered ReHo values in the putamen and lentiform. TDCS was an effective and safe add-on intervention for this small bipolar depression sample. The reduction of depression induced by tDCS is associated with a modulation of neural synchronization in the cortical and subcortical structures (ReHo values) within an emotion-related brain network.

Limbic and cortical regions as functional biomarkers associated with emotion regulation in bipolar disorder: A meta-analysis of neuroimaging studies

BACKGROUND

Bipolar disorder (BD) is a psychiatric disorder characterized by episodes of depression and mania, associated with impaired emotion processing. Several functional MRI (fMRI) studies have been used to investigate the structural and functional alteration in BD. Here, we aim to investigate the current fMRI findings of brain activation during emotion-regulation tasks between BD patients and healthy controls (HC).

METHODS

A systematic search through PubMed database for fMRI studies on bipolar patients and HC yielded 685 studies. We performed an activation likelihood estimation (ALE) on 21 studies for emotion regulation in BD patients and HC. Furthermore, we performed subgroup analyses for task performances in response time and accuracy between bipolar patients and HC.

RESULTS

The total sample included 21 fMRI studies, comprising 543 BD patients, compared to 565 HC. ALE maps for emotion-related tasks showed hyperactivation in BD patients in the caudate, amygdala, precentral gyrus, middle frontal gyri, and sub-gyrus. Whereas hypoactivation was seen in the inferior frontal gyrus and anterior cingulate gyrus.

LIMITATIONS

We could not apply a correction for p-value thresholds, as it needs large number of foci. Second, functional abnormalities were investigated for adult BD patients only, as BD patients have functional differences correlated with age.

CONCLUSIONS

Our results showed that limbic and cortical regions can represent a potential biomarker for the diagnosis and management of BD, by showing clustered brain regions of abnormal patterns of increased activation between BD patients and HC.

Posterior-prefrontal and medial orbitofrontal regions play crucial roles in happiness and sadness recognition

•

Brain areas underlying trade-off relations between emotions were identified.

•

Damage to the PPF area reduces accuracy of happiness recognition.

•

Damage to the PPF increases accuracy of sadness recognition.

•

A similar tendency was observed in orbitofrontal regions for sadness recognition.

•

Only a deficit in sadness, but not happiness, persisted in the chronic phase.

The core brain regions responsible for basic human emotions are not yet fully understood. We investigated the key areas responsible for emotion recognition of facial expressions of happiness and sadness using data obtained from patients who underwent local brain resection. A total of 44 patients with right cerebral hemispheric brain tumors and 33 healthy volunteers were enrolled and subjected to a facial expression recognition test. Voxel-based lesion-symptom mapping was performed to investigate the relationship between the accuracy of emotion recognition and the resected regions. Consequently, trade-off relationships were discovered: the posterior-prefrontal region was related to a low score of happiness recognition and a high score of sadness recognition (disorder-of-happiness group), whereas the medial orbitofrontal region was related to a low score of sadness recognition and a high score of happiness recognition (disorder-of-sadness group). The emotion recognition score in both the happiness and sadness disorder groups was significantly lower than that in the control group (p = 0.0009 and p = 0.021, respectively). Interestingly, the deficit in happiness recognition was temporary, whereas the deficit in sadness recognition persisted during the chronic phase. Using graph theoretical analysis, we identified structural connectivity between the posterior-prefrontal and medial orbitofrontal regions. When either of these regions was damaged, the tract volume connecting them was significantly reduced (p = 0.013). These results indicate that the posterior-prefrontal and medial orbitofrontal regions may be crucial for maintaining a balance between happiness and sadness recognition in humans. Investigating the clinical impact of certain area resections using lesion studies combined with connectivity analysis is a useful neuroimaging method for understanding neural networks.

Accelerated cortical thinning and volume reduction over time in young people at high genetic risk for bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a familial psychiatric disorder associated with frontotemporal and subcortical brain abnormalities. It is unclear whether such abnormalities are present in relatives without BD, and little is known about structural brain trajectories in those at risk.

METHOD

Neuroimaging was conducted at baseline and at 2-year follow-up interval in 90 high-risk individuals with a first-degree BD relative (HR), and 56 participants with no family history of mental illness who could have non-BD diagnoses. All 146 subjects were aged 12-30 years at baseline. We examined longitudinal change in gray and white matter volume, cortical thickness, and surface area in the frontotemporal cortex and subcortical regions.

RESULTS

Compared to controls, HR participants showed accelerated cortical thinning and volume reduction in right lateralised frontal regions, including the inferior frontal gyrus, lateral orbitofrontal cortex, frontal pole and rostral middle frontal gyrus. Independent of time, the HR group had greater cortical thickness in the left caudal anterior cingulate cortex, larger volume in the right medial orbitofrontal cortex and greater area of right accumbens, compared to controls. This pattern was evident even in those without the new onset of psychopathology during the inter-scan interval.

CONCLUSIONS

This study suggests that differences previously observed in BD are developing prior to the onset of the disorder. The pattern of pathological acceleration of cortical thinning is likely consistent with a disturbance of molecular mechanisms responsible for normal cortical thinning. We also demonstrate that neuroanatomical differences in HR individuals may be progressive in some regions and stable in others.

Amygdala structure and function in paediatric bipolar disorder and high-risk youth: A systematic review of magnetic resonance imaging findings

OBJECTIVE

Converging evidence from structural and functional magnetic resonance imaging (MRI) studies points to amygdala alteration as crucial in the development of paediatric bipolar disorder (pBP). The high number of recent studies prompted us to comprehensively evaluate findings. We aimed to systematically review structural and functional MRI studies investigating the amygdala in patients with pBP and in youth at high-risk (HR) for developing pBP.

METHODS

We searched PubMed from any time to 25 September 2020 using: 'amygdala AND (MRI OR magnetic resonance imaging) AND bipolar AND (pediatr* OR child OR children OR childhood OR adolescent OR adolescents OR adolescence OR young OR familial OR at-risk OR sibling* OR offspring OR high risk)'. In this review, we adhered to the PRISMA statement.

RESULTS

Amygdala hyperactivity to emotional stimuli is the most commonly reported finding in youth with pBP and HR compared to healthy peers (HC), whereas findings from structural MRI studies are inconsistent.

CONCLUSIONS

Hyperactivation of the amygdala might be an endophenotype of pBP.

Evaluating endophenotypes for bipolar disorder

BACKGROUND

Phenotypic heterogeneity is a major impediment to the elucidation of the neurobiology and genetics of bipolar disorder. Endophenotype could help in reducing heterogeneity by defining biological traits that are more direct expressions of gene effects. The aim of this review is to examine the recent literature on clinical, epidemiological, neurobiological, and genetic findings and to select and evaluate candidate endophenotypes for bipolar disorder. Evaluating putative endophenotype could be helpful in better understanding the neurobiology of bipolar disorder by improving the definition of bipolar-related phenotypes in genetic studies. In this manner, research on endophenotypes could be useful to improve psychopathological diagnostics in the long-run by dissecting psychiatric macro phenotypes into biologically valid components.

MAIN BODY

The associations among the psychopathological and biological endophenotypes are discussed with respect to specificity, temporal stability, heritability, familiarity, and clinical and biological plausibility. Numerous findings regarding brain function, brain structure, neuropsychology and altered neurochemical pathways in patients with bipolar disorder and their relatives deserve further investigation. Overall, major findings suggest a developmental origin of this disorder as all the candidate endophenotypes that we have been able to select are present both in the early stages of the disorder as well as in subjects at risk.

CONCLUSIONS

Among the stronger candidate endophenotypes, we suggest circadian rhythm instability, dysmodulation of emotion and reward, altered neuroimmune state, attention and executive dysfunctions, anterior cingulate cortex thickness and early white matter abnormalities. In particular, early white matter abnormalities could be the result of a vulnerable brain on which new stressors are added in young adulthood which favours the onset of the disorder. Possible pathways that lead to a vulnerable brain are discussed starting from the data about molecular and imaging endophenotypes of bipolar disorder.

Deficits in explicit emotion regulation in bipolar disorder: a systematic review

Background

This study aimed to compile and synthesize studies investigating explicit emotion regulation in patients with bipolar disorder and individuals at risk of developing bipolar disorder. The importance of explicit emotion regulation arises from its potential role as a marker for bipolar disorders in individuals at risk and its potent role in therapy for bipolar disorder patients.

Methods

To obtain an exhaustive compilation of studies dealing specifically with explicit emotion regulation in bipolar disorder, we conducted a systematic literature search in four databases. In the 15 studies we included in our review, the emotion-regulation strategies maintenance, distraction, and reappraisal (self-focused and situation-focused) were investigated partly on a purely behavioral level and partly in conjunction with neural measures. The samples used in the identified studies included individuals at increased risk of bipolar disorder, patients with current affective episodes, and patients with euthymic mood state.

Results

In summary, the reviewed studies' results indicate impairments in explicit emotion regulation in individuals at risk for bipolar disorder, patients with manic and depressive episodes, and euthymic patients. These deficits manifest in subjective behavioral measures as well as in neural aberrations. Further, our review reveals a discrepancy between behavioral and neural findings regarding explicit emotion regulation in individuals at risk for bipolar disorders and euthymic patients. While these groups often do not differ significantly in behavioral measures from healthy and low-risk individuals, neural differences are mainly found in frontostriatal networks.

Conclusion

We conclude that these neural aberrations are a potentially sensitive measure of the probability of occurrence and recurrence of symptoms of bipolar disorders and that strengthening this frontostriatal route is a potentially protective measure for individuals at risk and patients who have bipolar disorders.

The emotional face of anorexia nervosa: The neural correlates of emotional processing

Social-emotional processing difficulties have been reported in Anorexia Nervosa (AN), yet the neural correlates remain unclear. Previous neuroimaging work is sparse and has not used functional connectivity paradigms to more fully explore the neural correlates of emotional difficulties. Fifty-seven acutely unwell AN (AAN) women, 60 weight-recovered AN (WR) women and 69 healthy control (HC) women categorised the gender of a series of emotional faces while undergoing Functional Magnetic Resonance Imaging. The mean age of the AAN group was 19.40 (2.83), WR 18.37 (3.59) and HC 19.37 (3.36). A whole brain and psychophysical interaction connectivity approach was used. Parameter estimates from significant clusters were extracted and correlated with clinical symptoms. Whilst no group level differences in whole brain activation were demonstrated, significant group level functional connectivity differences emerged. WR participants showed increased connectivity between the bilateral occipital face area and the cingulate, precentral gyri, superior, middle, medial and inferior frontal gyri compared to AAN and HC when viewing happy valenced faces. Eating disorder symptoms and parameter estimates were positively correlated. Our findings characterise the neural basis of social-emotional processing in a large sample of individuals with AN.

Amygdala connectivity during emotional face perception in psychotic disorders

Emotional face perception (EFP) deficits have been identified as a significant feature of psychotic disorders and are associated with symptoms and real-world functioning in these disorders. The amygdala is frequently implicated in EFP and bears extensive structural connectivity with other brain regions supporting EFP. Amygdala functional connectivity during attentional control of implicitly processed emotional faces in psychotic disorders is well examined. However, it is unclear whether amygdala functional connectivity while explicitly processing emotional faces contributes to EFP deficits in psychotic disorders. Further, it is unclear whether these connectivity differences are associated with symptoms or functioning and if these relationships are transdiagnostic across psychotic disorders. We used functional magnetic resonance imaging (fMRI) and seed-based functional connectivity analyses to examine connectivity of amygdala to other regions of the face processing network during an EFP task. The sample consisted of 55 cases with psychotic disorders and 29 participants with no history of psychosis (NP). Results indicated that, compared to NP, cases showed worse accuracy, greater inferior frontal gyrus (IFG) activation, and greater amygdala-insula connectivity while matching emotional and neutral faces. Additionally, worse accuracy, greater IFG activation, greater amygdala-insula and amygdala-IFG connectivity during emotional vs. neutral faces was associated with worse negative symptoms and greater deficits in social and global functioning in cases. Importantly, these relationships transcended diagnostic categories, and applied across psychotic disorders. The present study presents compelling evidence relating alterations in amygdala functional connectivity during explicit EFP with clinical and functioning deficits seen across psychotic disorders.

The activity and connectivity of the facial emotion processing neural circuitry in bipolar disorder: a systematic review

BACKGROUND

Facial emotion processing abnormalities may be a trait feature of bipolar disorder (BD). These social cognitive impairments may be due to alterations in the neural processing of facial affective information in visual ("core"), and limbic and prefrontal ("extended") networks, however, the precise neurobiological mechanism(s) underlying these symptoms are unclear.

METHODS

We conducted a systematic review to appraise the literature on the activity and connectivity of the facial emotion processing neural circuitry in BD. Two reviewers undertook a search of the electronic databases PubMed, Scopus and PsycINFO, to identify relevant literature published since inception up until September 2019. Study eligibility criteria included; BD participants, neuroimaging, and facial emotion processing tasks.

RESULTS

Out of an initial yield of 6121 articles, 66 were eligible for inclusion in this review. We identified differences in neural activity and connectivity within and between occipitotemporal, limbic, and prefrontal regions, in response to facial affective stimuli, in BD compared to healthy controls.

LIMITATIONS

The methodologies used across studies varied considerably.

CONCLUSIONS

The findings from this review suggest abnormalities in both the activity and connectivity of facial emotion processing neural circuitry in BD. It is recommended that future research aims to further define the connectivity and spatiotemporal course of neural events within and between occipitotemporal, limbic, and prefrontal regions.

Where does fear originate in the brain? A coordinate-based meta-analysis of explicit and implicit fear processing

Processing of fear is of crucial importance for human survival and it can generally occur at explicit and implicit conditions. It is worth noting that explicit and implicit fear processing produces different behavioral and neurophysiological outcomes. The present study capitalizes on the Activation Likelihood Estimation (ALE) method of meta-analysis to identify: (a) the "core" network of fear processing in healthy individuals; (b) common and specific neural activations associated with explicit and implicit processing of fear. Following PRISMA guidelines, a total of 92 fMRI and PET studies were included in the meta-analysis. The overall analysis show that the core fear network comprises the amygdala, pulvinar, and fronto-occipital regions. Both implicit and explicit fear processing activated amygdala, declive, fusiform gyrus, and middle frontal gyrus, suggesting that these two types of fear processing share a common neural substrate. Explicit fear processing elicited more activations at the pulvinar and parahippocampal gyrus, suggesting visual attention/orientation and contextual association play important roles during explicit fear processing. In contrast, implicit fear processing elicited more activations at the cerebellum-amygdala-cortical pathway, indicating an 'alarm' system underlying implicit fear processing. These findings have shed light on the neural mechanism underlying fear processing at different levels of awareness.

Perceptual Differences in Emotionally Ambiguous Neutral Faces Among Individuals Displaying Clinically Significant Insomnia Symptoms

Many psychiatric populations present deficits in the processing of neutral faces. While insomnia is associated with perceptual alterations of facially expressed fear, sadness, and happiness, the perception of neutral faces have not been explored in this population. This study compared normal sleepers and individuals experiencing insomnia symptoms in their expression intensity ratings of neutral faces. A total of 56 normal sleepers scoring <5 on the Insomnia Severity Index and 58 individuals experiencing clinically significant insomnia symptoms scoring ≥15 on the Insomnia Severity Index (19.24 ± 3.53) observed 12 neutral facial photographs from the Karolinska Directed Emotional Faces database. Participants rated the extent to which each face appeared as attractive, sad, happy, trustworthy, approachable, healthy, and sociable. The results revelated a main effect of group, F(1,117) = 4.04, p = .047, and expression, F(7, 819) = 39.08, p = .001, on intensity ratings. While no significant Group × Expression interaction was confirmed, F(7,819)=1.03, p = .41, simple effects analysis determined that those experiencing insomnia symptoms rated neutral faces as significantly more attractive (34.30 ± 14.82; t(117) = -2.73, p = .007; Cohen's d = 0.50) and happy (34.83 ± 13.87; t(117) = -2.23, p = .028; Cohen's d = 0.41) compared with normal sleepers (Attractive: 26.89 ± 14.76; Happy: 28.90 ± 12.48). The present outcomes tentatively suggest that individuals experiencing clinically significant insomnia symptoms differentially perceive neutral faces when compared with normal sleepers. These outcomes present potentially negative psychosocial implications for those with insomnia.

Aberrant cognition in newly diagnosed patients with bipolar disorder and their unaffected relatives

BACKGROUND

Patients with bipolar disorder (BD) experience persistent impairments in both affective and non-affective cognitive function, which is associated with a worse course of illness and poor functional outcomes. Nevertheless, the temporal progression of cognitive dysfunction in BD remains unclear and the identification of objective endophenotypes can inform the aetiology of BD.

METHODS

The present study is a cross-sectional investigation of cognitive baseline data from the longitudinal Bipolar Illness Onset-study. One hundred seventy-two remitted patients newly diagnosed with BD, 52 of their unaffected relatives (UR), and 110 healthy controls (HC) were compared on a large battery of behavioural cognitive tasks tapping into non-affective (i.e. neurocognitive) and affective (i.e. emotion processing and regulation) cognition.

RESULTS

Relative to HCs, patients with BD exhibited global neurocognitive deficits (ps < 0.001), as well as aberrant emotion processing and regulation (ps ⩽ 0.011); including decreased emotional reactivity to positive social scenarios, impaired ability to down-regulate positive emotion, as well as a specific deficit in the ability to recognise surprised facial expressions. Their URs also showed a trend towards difficulties identifying surprised faces (p = 0.075). No other differences in cognitive function were found for URs compared to HCs.

CONCLUSIONS

Neurocognitive deficits and impairments within emotion processing and regulation may be illness-related deficits of BD that present after illness-onset, whereas processing of emotional faces may represent an early risk marker of BD. However, longitudinal studies are needed to examine the association between cognitive impairments and illness progression in BD.

Facial emotion recognition deficits in patients with bipolar disorder and their healthy parents

BACKGROUND

There is evidence on deficits in facial emotion recognition (FER) in patients with bipolar disorder (BD), and these deficits may be present in individuals with genetic risk for BD. This study investigated facial emotion identification and discrimination abilities in patients with BD, their parents, and healthy controls.

MATERIALS AND METHODS

This study included 38 patients with bipolar I disorder and 30 healthy controls for patients as well as 30 healthy mothers and 30 healthy fathers of these patients and 30 healthy controls who matched the mothers and fathers for age, gender, and education (total 188 participants). Facial Emotion Identification and Discrimination Tests were applied to all participants; the Hamilton Depression Rating Scale and Young Mania Rating Scale were applied to patients and their control group.

RESULTS

Facial Emotion Identification and Discrimination Test scores of patients and their parents were reasonably lower than their matching control groups. Moreover, we found that difficulty in FER affected more emotions in mothers than in fathers and mothers performed significantly worse than patients in the identification of angry and embarrassed faces.

CONCLUSION

These findings indicate that parents of patients with BD have impairment with recognizing facial emotions and suggest that there may be an association between FER of patients with BD and that of their mothers.

The impact of familial risk and early life adversity on emotion and reward processing networks in youth at-risk for bipolar disorder

A recently developed risk calculator for bipolar disorder (BD) accounts for clinical and parental psychopathology. Yet, it is understood that both familial predisposition and early life adversity contribute to the development of BD. How the interplay between these two factors influence emotion and reward processing networks in youth at risk for BD remains unclear. In this exploratory analysis, offspring of BD parents performed emotion and reward processing tasks while undergoing a fMRI scan. Risk calculator score was used to assess risk for developing BD in the next 5 years. Environmental risk was tabulated using the Stressful Life Events Schedule (SLES). Emotion and reward processing networks were investigated for genetic and/or environment interactions. Interaction effects were found between risk calculator scores, negative SLES score and activity in right amygdala and bilateral fusiform gyri during the emotion processing task, as well as activity in the fronto-, striatal, and parietal regions during the reward processing task. Our findings are preliminary; however, they support the unique and interactive contributions of both familial and environmental risk factors on emotion and reward processing within OBP. They also identify potential neural targets to guide development of interventions for youth at greatest risk for psychiatric disorders.

Genetic Predisposition and Disease Expression of Bipolar Disorder Reflected in Shape Changes of the Anterior Limbic Network

Bipolar disorder (BD) is a genetically and phenotypically complex psychiatric disease. Although previous studies have suggested that the relatives of BD patients have an increased risk of experiencing affective disturbances, most relatives who have similar genotypes may not manifest the disorder. We aim to identify the neuroimaging alterations—specifically, the cortical folding structures of the anterior limbic network (ALN)—in BD patients and their siblings, compared to healthy controls. The shared alterations in patients and their siblings may indicate the hereditary predisposition of BD, and the altered cortical structures unique to BD patients may be a probe of BD expression. High-resolution, T1-weighted magnetic resonance images for 17 euthymic patients with BD, 17 unaffected siblings of BD patients, and 22 healthy controls were acquired. We categorized the cortical regions within the ALN into sulcal and gyral areas, based on the shape index, followed by the measurement of the folding degree, using the curvedness. Our results revealed that the changes in cortical folding in the orbitofrontal and temporal regions were associated with a hereditary predisposition to BD. Cortical folding structures in multiple regions of the ALN, particularly in the striatal–thalamic circuit and anterior cingulate cortex, could be used to differentiate BD patients from healthy controls and unaffected siblings. We concluded that the cortical folding structures of ALN can provide potential biomarkers for clinical diagnosis of BD and differentiation from the unaffected siblings.

Neural response to emotional faces in monozygotic twins: association with familial risk of affective disorders

BACKGROUND

Aberrant neural and cognitive response to emotional faces has been observed in people at familial risk of an affective disorder. In this functional MRI study of monozygotic twins, we explored neural correlates of the attentional avoidance of emotional faces that we had previously observed in high-risk versus affected twins, and whether an abnormal neural response to emotional faces represents a risk endophenotype.

METHODS

We recruited unaffected monozygotic twins with a co-twin history of mood episodes (high-risk), monozygotic twins with previous mood episodes (affected) and monozygotic twins with no personal or first-degree history of mood episodes (low-risk) between December 2014 and January 2017 based on a nationwide register linkage. Participants viewed fearful and happy faces while performing a gender discrimination task during functional MRI (fMRI) and performed emotional faces dot-probe and facial expression recognition tasks outside the scanner.

RESULTS

A total of 129 monozygotic twins underwent whole-brain fMRI. Highrisk twins (n = 38) displayed greater medial and superior prefrontal response to emotional faces than affected twins (n = 62). This greater activity correlated with stronger attentional avoidance of emotional faces in high-risk twins. In contrast, high-risk and affected twins showed no aberrant neural activity to emotional faces compared with low-risk twins (n = 29).

LIMITATIONS

A limitation of this study was its cross-sectional design.

CONCLUSION

Greater recruitment of the medial and superior prefrontal cortex during implicit emotion processing in high-risk versus affected twins may represent a compensatory or resilience mechanism. In contrast, aberrant neural response to emotional faces does not seem to be a risk endophenotype for affective disorders.

Nonlinear dynamics of mood regulation in unaffected first-degree relatives of bipolar disorder patients

BACKGROUND

Mood regulation is a complex and poorly understood process. In this study, we aimed to analyze the underlying dynamics of mood regulation in unaffected first degree relatives of patients diagnosed with bipolar disorder using time-series analysis.

METHODS

We recruited 30 unaffected first-degree relatives of bipolar disorder patients. Participants rated their mood, anxiety and energy levels using a paper-based visual analog scale; they recorded their sleep and life events as well. Participants provided information on these variables over a three month period, twice per day. We compared their data using Box-Jenkins time series analysis with data from 30 healthy controls (HC) and 30 euthymic bipolar patients (BD) to obtain information on the autocorrelation and cross-correlation of the series, and calculated entropy for mood, anxiety and energy series.

RESULTS

We analyzed 14,980 data points: 5200 in the healthy control group; 4970 in the bipolar group and 4810 in the unaffected relatives group. There were no significant differences between groups in terms of age, sex or education levels. Using Kolmogorov-Smirnov test, we found that individual measures were normally distributed in the whole sample (D = 0.23, p > 0.1). Autocorrelation functions for mood in all groups are governed by the ARIMA (1,1,0) model, which means that current values in the series are related to one previous point only. In terms of entropy for the mood series, unaffected relatives and bipolar patients showed lower values [mean (SD) : 1.028 ± 0.679; 1.042 ± 0.680], respectively, compared to healthy controls [(1.476 ± 0.33); F (2,74) = 4.39, p < 0.01]. The same case was seen in the energy series, with lower values in the unaffected relatives and bipolar patient groups [mean (SD) : 1.644 ± 0.566; 1.511 ± 0.879], respectively, compared to healthy controls [2.230 ± 0.531; F(2, 75) = 7.89, p < 0.001].

LIMITATIONS

Low resolution for the visual analog scale.

CONCLUSIONS

Using nonlinear analyses, we found that the underlying structure of mood regulation in unaffected relatives is undistinguishable from the one found in bipolar patients. Compared to healthy controls, both bipolar patients and their unaffected relatives showed lower entropy levels, which is in keeping with a more rigid system, not as flexible to cope with the demands of a changing environment.

White matter - emotion processing activity relationships in youth offspring of bipolar parents

BACKGROUND

Early detection of Bipolar Disorder (BD) is critical for targeting interventions to delay or prevent illness onset. Yet, the absence of objective BD biomarkers makes accurately identifying at-risk youth difficult. In this study, we examined how relationships between white matter tract (WMT) structure and activity in emotion processing neural circuitry differentiate youth at risk for BD from youth at risk for other psychiatric disorders.

METHODS

Offspring (ages 8-17) of parents with BD (OBP, n = 32), offspring of comparison parents with non-BD psychopathology (OCP, n = 30), and offspring of healthy parents (OHP, n = 24) underwent diffusion tensor and functional magnetic resonance imaging while performing an emotional face processing task. Penalized and multiple regression analyses included GROUP(OBP,OCP)xWMT interactions as main independent variables, and emotion processing activity as dependent variables, to determine significant group differences in WMT-activity relationships.

RESULTS

8 GROUPxWMT interaction variables contributed to 16.5% of the variance in amygdala and prefrontal cortical activity to happy faces. Of these, significant group differences in slopes (inverse for OBP, positive for OCP) existed for the relationship between forceps minor radial diffusivity and rostral anterior cingulate activity (p = 0.014). Slopes remained significantly different in unmedicated youth without psychiatric disorders (p = 0.017) and were moderated by affective lability symptoms (F(1,29) = 5.566, p = 0.036).

LIMITATIONS

Relatively small sample sizes were included.

CONCLUSIONS

Forceps minor radial diffusivity-rostral anterior cingulate activity relationships may reflect underlying neuropathological processes that contribute to affectively labile youth at risk for BD and may help differentiate them from youth at risk for other psychiatric disorders.

Neural correlates of improved recognition of happy faces after erythropoietin treatment in bipolar disorder

OBJECTIVE

Bipolar disorder is associated with impairments in social cognition including the recognition of happy faces. This is accompanied by imbalanced cortico-limbic response to emotional faces. We found that EPO improved the recognition of happy faces in patients with bipolar disorder. This randomized, controlled, longitudinal fMRI study explores the neuronal underpinnings of this effect.

METHOD

Forty-four patients with bipolar disorder in full or partial remission were randomized to eight weekly erythropoietin (EPO; 40 000 IU) or saline (NaCl 0.9%) infusions in a double-blind, parallel-group design. Participants underwent whole-brain fMRI at 3T, mood ratings and blood tests at baseline and week 14. During fMRI, participants viewed happy and fearful faces and performed a gender discrimination task.

RESULTS

Thirty-four patients had complete pre- and post-treatment fMRI data (EPO: N = 18, saline: N = 16). Erythropoietin vs. saline increased right superior frontal response to happy vs. fearful faces. This correlated with improved happiness recognition in the EPO group. Erythropoietin also enhanced gender discrimination accuracy for happy faces. These effects were not influenced by medication, mood, red blood cells or blood pressure.

CONCLUSIONS

Together with previous findings, the present observation suggests that increased dorsal prefrontal attention control is a common mechanism of EPO-associated improvements across several cognitive domains.

Reliability of neural activation and connectivity during implicit face emotion processing in youth

Face emotion imaging paradigms are widely used in both healthy and psychiatric populations. Here, in children and adolescents, we evaluate the test-retest reliability of blood oxygenation-level dependent (BOLD) activation and task-based functional connectivity on a widely used implicit face emotion processing task (i.e., gender labeling). Twenty-five healthy youth (M age = 13.97 year s; 60% female) completed two functional magnetic resonance imaging (fMRI) scan sessions approximately two months apart. Participants identified the gender of faces displaying angry, fearful, happy, and neutral emotions. A Bayesian adaptation of the intraclass correlation (ICC) assessed reliability of evoked BOLD activation and amygdala seed-based functional connectivity on task events vs. baseline as well as contrasts between face emotions. For each face emotion vs. baseline, good reliability of activation was demonstrated across key emotion processing regions including middle, medial, and inferior frontal gyri. However, contrasts between face emotions yielded variable results. Contrasts of angry to neutral or happy faces exhibited good reliability of amygdala connectivity to prefrontal regions. Contrasts of fearful to happy faces exhibited good reliability of activation in the anterior cingulate. Findings inform the reproducibility literature and emphasize the need for continued evaluation of task reliability.

Sleep-related attentional bias for tired faces in insomnia: Evidence from a dot-probe paradigm

People with insomnia often display an attentional bias for sleep-specific stimuli. However, prior studies have mostly utilized sleep-related words and images, and research is yet to examine whether people with insomnia display an attentional bias for sleep-specific (i.e. tired appearing) facial stimuli. This study aimed to examine whether individuals with insomnia present an attentional bias for sleep-specific faces depicting tiredness compared to normal-sleepers. Additionally, we aimed to determine whether the presence of an attentional bias was characterized by vigilance or disengagement. Forty-one individuals who meet the DSM-5 criteria for Insomnia Disorder and 41 normal-sleepers completed a dot-probe task comprising of neutral and sleep-specific tired faces. The results demonstrated that vigilance and disengagement scores differed significantly between the insomnia and normal-sleeper groups. Specifically, individuals with insomnia displayed difficulty in both orienting to and disengaging attention from tired faces compared to normal-sleepers. Using tired facial stimuli, the current study provides novel evidence that insomnia is characterized by a sleep-related attentional bias. These outcomes support cognitive models of insomnia by suggesting that individuals with insomnia monitor tiredness in their social environment.

Altered N170 and mood symptoms in bipolar disorder: An electrophysiological study of configural face processing

OBJECTIVES

Altered social behavior during mood episodes in bipolar disorder often has detrimental and long-lasting interpersonal consequences. Abnormal face processing may play a role in linking brain functions to clinical symptoms and behavior. This study aimed to understand configural face processing in bipolar disorder as a function of basic communicative attributes of the face and mood symptoms using event-related brain potentials (ERPs).

METHODS

Forty-two participants with bipolar I disorder (BP) and 43 healthy controls (HC) viewed face stimuli varying in emotion (neutral or fearful), head orientation (forward or deviated), and gaze direction (direct or averted) while ERPs were recorded. Configural face processing was indexed by the N170 wave.

RESULTS

BP participants had comparable overall N170 amplitude and peak latency to HC, although timing was more variable in the BP group. Abnormal N170 modulations by communicative face attributes were observed in BP: exaggerated sensitivity to emotion (fearful > neutral) in the left hemisphere, and reduced sensitivity to gaze-head incongruency (where N170 is normally larger in response to faces with incongruent than congruent gaze and head direction) in the right hemisphere. The former was not associated with mood symptoms, suggesting a heightened trait-like sensitivity to negative emotions. The latter was correlated with greater manic symptoms, indicating that an impaired perceptual sensitivity to faces with features signaling incongruent social attention may underlie social deficits observed during mania.

CONCLUSIONS

These findings suggest a pathophysiological role of altered configural face processing in the phenomenology of bipolar disorder, and call for further investigations to evaluate its potential as a biomarker and treatment target.

Behavioral and Neural Sustained Attention Deficits in Bipolar Disorder and Familial Risk of Bipolar Disorder

BACKGROUND

Few neuroimaging studies compare individuals affected with bipolar disorder (BP), at high familial risk of BP, and at low risk to identify endophenotypes for BP. None have examined variability in attention, despite promising behavioral work in this area. We used functional magnetic resonance imaging (fMRI) methods uniquely powered to compare the neural correlates of attention variability in these three groups.

METHODS

The present study examined 8- to 25-year-old individuals (n = 106) who completed an fMRI attention task: 24 with BP, 29 at risk based on a first-degree relative with BP, and 53 healthy, low-risk individuals. Group differences in intrasubject variability in reaction time were examined, and a sophisticated fMRI analytic approach was used to quantify precisely trialwise associations between reaction time and brain activity. The latter has not been examined previously in BP or risk of BP.

RESULTS

Relative to healthy individuals, those with BP or at risk for BP exhibited increased reaction time variability (F_2,102 = 4.26, p = .02, η_p² = .08). Importantly, we identified blunted relationships between trialwise variation in reaction time and brain activity in the inferior and middle frontal gyri, precuneus, cingulate cortex, caudate, and postcentral gyrus (all regions: p < .001, η_p² > .06) in both at-risk and BP individuals compared with healthy, low-risk individuals. This blunting partially mediated group differences in reaction time variability (β = .010, 95% confidence interval 0.002 to 0.020, Sobel Z = 2.08, p = .038).

CONCLUSIONS

Blunting in key frontal, cingulate, and striatal areas was evident in unaffected, at-risk individuals and in euthymic BP patients. Elucidating such novel neural endophenotypes can facilitate new approaches to BP prediction, diagnosis, and prevention.

Dysfunctional gaze processing in bipolar disorder

Gaze conveys emotional information, and humans present sensitivity to its direction from the earliest days of life. Bipolar disorder is a disease characterized by fluctuating states of emotional and cognitive dysregulation. To explore the role of attentional control on face processing in bipolar patients (BP) we used gaze direction as an emotion modulation parameter in a two-back Working Memory (WM) task while high-density EEG data were acquired. Since gaze direction influences emotional attributions to faces with neutral expressions as well, we presented neutral faces with direct and averted gaze. Nineteen euthymic BP and a sample of age- and gender-matched controls were examined.

In BP we observed diminished P200 and augmented P300 evoked responses, differentially modulated by non-repeated or repeated faces, as well as by gaze direction. BP showed a reduced P200 amplitude, significantly stronger for faces with direct gaze than averted gaze. Source localization of P200 indicated decreased activity in sensory-motor regions and frontal areas suggestive of abnormal affective processing of neutral faces.

The present study provides neurophysiological evidence for abnormal gaze processing in BP and suggests dysfunctional processing of direct eye contact as a prominent characteristic of bipolar disorder.

•

This ERP study identified abnormalities in gaze processing in bipolar patients.

•

We observed functional anomalies in the P200 and P300 evoked responses.

•

BP showed a strong suppression of the P200 for faces with direct gaze.

•

Source localization indicated decreased activity in sensory-motor regions.

Initial Psychometric Properties of the Korean Altman Self-Rating Mania Scale: Preliminary Validation Study in a Non-Clinical Sample

OBJECTIVE

We aimed to examine the reliability and validity of the Korean Altman Self-Rating Mania Scale (K-ASRM) in a large sample of Korean non-clinical undergraduates.

METHODS

Participants (n=1,091) filled out the K-ASRM with other self-report questionnaires assessing bipolarity, mood symptoms and affect. Reliability test, exploratory factor analysis and correlation analyses were conducted to examine its psychometric properties.

RESULTS

The reliability of the K-ASRM was adequate (Cronbach's α=0.73, item-to-total correlation 0.53-0.78) and the exploratory factor analysis yielded one factor of mania. The K-ASRM demonstrated significant associations with measures of hypomanic personality (r=0.33), lifetime history of hypomanic symptoms (r=0.23). Also, the K-ASRM was significantly correlated with positive affect (r=0.53), negative affect (r=-0.17) and depressive symptoms (r=-0.35).

CONCLUSION

These results suggest preliminary possibility that the K-ASRM can be utilized as self-rating tool for mania in Korea as well as future directions for further validation.

Differential Abnormal Pattern of Anterior Cingulate Gyrus Activation in Unipolar and Bipolar Depression: an fMRI and Pattern Classification Approach

Distinguishing bipolar disorder from major depressive disorder is a major challenge in psychiatric treatment. Consequently, there has been growing interest in identifying neuronal biomarkers of disorder-specific pathophysiological processes to differentiate affective disorders. Thirty-six depressed bipolar patients, 36 depressed unipolar patients, and 36 matched healthy controls (HCs) participated in an fMRI experiment. Emotional faces served as stimuli in a matching task. We investigated neural activation towards angry, fearful, and happy faces focusing on prototypical regions related to emotion processing, ie, the amygdala and the anterior cingulate gyrus (ACG). Furthermore, we employed a whole-brain and a multivariate pattern classification analysis. Unipolar patients showed abnormally reduced ACG activation toward happy and fearful faces compared with bipolar patients and HCs respectively. Furthermore, the whole-brain analysis revealed significantly increased activation in bipolar patients compared with unipolar patients in the fearful condition in the right frontal and parietal cortex. Moreover, the multivariate pattern classification analysis yielded significant classification rates of up to 72% based on ACG activation elicited by fearful faces. Our results question the rather 'amygdalocentric' neurobiological models of mood disorders. We observed patterns of abnormally reduced ventral and supragenual ACG activation, potentially indicating impaired bottom-up emotion processing and automatic emotion regulation specifically in unipolar but not in bipolar individuals.

Effects of risk for bipolar disorder on brain function: A twin and family study

Bipolar disorder (BPD) is associated with altered regional brain function during the performance of cognitive tasks. The relative contribution of genetic and environmental risk factors for BPD to these changes has not yet been quantified. We sought to address this issue in a functional neuroimaging study of people who varied in their risk for BPD. Functional magnetic resonance imaging was used to study 124 subjects (29 twin and 9 sibling pairs with at least one member with BPD, and 24 healthy twin pairs) performing a working memory task. We assessed the influence of risk for BPD on regional brain function during the task in a two stage process. Firstly, we identified areas where there were group differences in activation. Secondly, we estimated the heritability and phenotypic correlation of activation and BPD using genetic modeling. BPD was associated with increased activation in the anterior cingulate, orbitofrontal, medial prefrontal, and left precentral cortices, and in the precuneus. Within these regions, activation in the orbitofrontal cortex rendered the most significant heritability estimate (h²=0.40), and was significantly correlated with BPD phenotype (r_ph=0.29). A moderate proportion of the genetic influences (r_g=0.69) acting on both BPD and on the degree of orbitofrontal activation were shared. These findings suggest that genetic factors that confer vulnerability to BPD alter brain function in BPD.

Amplitude of low-frequency fluctuations in first-episode, drug-naïve depressive patients: A 5-year retrospective study

Despite different treatments and courses of illness, depressive symptoms appear similar in bipolar disorder (BD) and major depressive disorder (MDD), causing BD with an onset of depressive episode being frequently misdiagnosed as MDD, and leading to inappropriate treatment and poor clinical outcomes. Therefore, there is an urgent need to explore underlying neural basis to distinguish BD from MDD. The medical records of 80 first-episode, drug-naïve depressive patients with an initial diagnosis of MDD and illness duration of at least 5 years were reviewed retrospectively for this study. Fourteen bipolar depressed patients with a diagnosis conversion from MDD to BD, 14 patients with diagnosis of MDD, and 14 healthy subjects demographically matched with the BD group, were selected to participate in the study. Firstly, we examined whether there were differences among the three groups in whole brain fALFF during resting state. Secondly, clusters showing group differences in fALFF in any two groups were chosen as regions of interest (ROI) and then correlation between clinical features and fALFF values of ROIs were calculated. The BD group showed increased fALFF in bilateral putamen relative to both the MDD group and controls, while the MDD group exhibited decreased fALFF in left superior frontal gyrus (SFG) relative to both the BD group and controls (p < 0.05, corrected). Positive correlations between abnormality in the putamen and symptom severity were observed (significant for the MDD group, p = 0.043; marginally significant for the BD group, p = 0.060/0.076). These results implicate that abnormalities of key regions in the striatum and prefrontal areas may be trait markers for BD and MDD.

Emotion processing and psychosocial functioning in euthymic bipolar disorder

OBJECTIVE

To examine emotion processing in euthymic bipolar patients (EBP) compared to healthy controls. In addition, to determine whether or not there is an association between emotion processing and psychosocial functioning.

MATERIAL AND METHODS

A sample of 60 EBP and 60 healthy controls matched for age, gender, education level, and premorbid intelligence were studied. All subjects were assessed using the MATRICS Consensus Cognitive Battery (MCCB) and two additional executive function measures: the Trail Making Test-Part B and the Stroop Test. Emotion processing was examined using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Psychosocial functioning was assessed using the Functional Assessment Short Test (FAST).

RESULTS

Euthymic bipolar patients obtained lower scores than controls in all MSCEIT measures except for the using emotions branch. Likewise, EBP obtained a worse performance than healthy controls in all neurocognitive domains. Correlation between MSCEIT strategic area measures and FAST total score was found (r = -0.311; P < 0.016). Regression analysis showed that residual depressive symptomatology explains a 9.1% of the variance in functional outcome. MSCEIT strategic area score explained an additional 8.6%. Neurocognition did not increase the percentage of the variance explained by emotion processing.

CONCLUSIONS

Euthymic bipolar patients exhibit deficits in emotion processing. Emotion processing is associated with social functioning in these patients.

Brain functional effects of psychopharmacological treatments in bipolar disorder

Functional magnetic resonance imaging (fMRI) studies have contributed to the understanding of bipolar disorder. However the effect of medication on brain activation remains poorly understood. We conducted an extensive literature review on PubMed and ScienceDirect to investigate the influence of medication in fMRI studies, including both longitudinal and cross-sectional studies, which aimed at assessing this influence. Although we reported all reviewed studies, we gave greater emphasis to studies with the most robust methodology. One hundred and forty studies matched our inclusion criteria and forty-seven studies demonstrated an effect of pharmacological treatment on fMRI blood oxygen level dependent (BOLD) signal in adults and children with bipolar disorder. Out of these studies, nineteen were longitudinal. Most of cross-sectional studies suffered from methodological bias, due to post-hoc analyses performed on a limited number of patients and did not find any effect of medication. However, both longitudinal and cross-sectional studies showing an impact of treatment tend to suggest that medication prescribed to patients with bipolar disorder mostly influenced brain activation in prefrontal regions, when measured by tasks involving emotional regulation and processing as well as non-emotional cognitive tasks. FMRI promises to elucidate potential new biomarkers in bipolar disorder and could be used to evaluate the effect of new therapeutic compounds. Further research is needed to disentangle the effect of medication and the influence of the changes in mood state on brain activation in patients with bipolar disorder.

Deactivation in anterior cingulate cortex during facial processing in young individuals with high familial risk and early development of depression: fMRI findings from the Scottish Bipolar Family Study

BACKGROUND

Studies have identified perturbations in facial processing in bipolar disorder and major depressive disorder (MDD), but their relationship to genetic risk and early development of illness is unclear.

METHODS

The Scottish Bipolar Family Study is a prospective longitudinal investigation examining young individuals (age 16-25) at familial risk of mood disorder. Participants underwent functional MRI using an implicit facial processing task employing angry and neutral faces. An explicit facial expression recognition task was completed outside the scanner. Clinical outcomes obtained 2 years after the scan were used to categorise participants into controls (n = 54), high-risk individuals who had developed MDD (HR MDD; n = 30) and high-risk individuals who remained well (HR Well, n = 43).

RESULTS

All groups demonstrated activation patterns typically observed during facial processing, including activation of the amygdala, hippocampus, fusiform gyrus and middle frontal regions. Notably, the HR MDD group showed reduced activation of the anterior cingulate gyrus versus both the control and HR Well group for angry faces, and versus the HR Well group for neutral faces. Outside the scanner, the HR MDD group was less accurate in recognising fearful expressions than the HR Well group.

CONCLUSIONS

Here, we demonstrate functional abnormalities of the anterior cingulate cortex alongside facial emotional recognition deficits in high-risk individuals in the early stages of depression compared with both controls and at-risk individuals who remained well. These neural changes were associated with a current or future diagnosis of MDD and were not simply associated with increased familial risk.

Socio-demographic and Clinical Correlates of Facial Expression Recognition Disorder in the Euthymic Phase of Bipolar Patients

OBJECTIVE

Bipolar patients show social cognitive disorders. The objective of this study is to review facial expression recognition (FER) disorders in bipolar patients (BP) and explore clinical heterogeneity factors that could affect them in the euthymic phase: socio-demographic level, clinical and changing characteristics of the disorder, history of suicide attempt, and abuse.

METHOD

Thirty-four euthymic bipolar patients and 29 control subjects completed a computer task of explicit facial expression recognition and were clinically evaluated.

RESULTS

Compared with control subjects, BP patients show: a decrease in fear, anger, and disgust recognition; an extended reaction time for disgust, surprise and neutrality recognition; confusion between fear and surprise, anger and disgust, disgust and sadness, sadness and neutrality. In BP patients, age negatively affects anger and neutrality recognition, as opposed to education level which positively affects recognizing these emotions. The history of patient abuse negatively affects surprise and disgust recognition, and the number of suicide attempts negatively affects disgust and anger recognition.

CONCLUSIONS

Cognitive heterogeneity in euthymic phase BP patients is affected by several factors inherent to bipolar disorder complexity that should be considered in social cognition study.

Brain functional changes in first-degree relatives of patients with bipolar disorder: evidence for default mode network dysfunction

BACKGROUND

Relatively few studies have investigated whether relatives of patients with bipolar disorder show brain functional changes, and these have focused on activation changes. Failure of de-activation during cognitive task performance is also seen in the disorder and may have trait-like characteristics since it has been found in euthymia.

METHOD

A total of 20 euthymic patients with bipolar disorder, 20 of their unaffected siblings and 40 healthy controls underwent functional magnetic resonance imaging during performance of the n-back working memory task. An analysis of variance (ANOVA) was fitted to individual whole-brain maps from each set of patient-relative-matched pair of controls. Clusters of significant difference among the groups were used as regions of interest to compare mean activations/de-activations between them.

RESULTS

A single cluster of significant difference among the three groups was found in the whole-brain ANOVA. This was located in the medial prefrontal cortex, a region of task-related de-activation in the healthy controls. Both the patients and their siblings showed significantly reduced de-activation compared with the healthy controls in this region, but the failure was less marked in the relatives.

CONCLUSIONS

Failure to de-activate the medial prefrontal cortex in both euthymic bipolar patients and their unaffected siblings adds to evidence for default mode network dysfunction in the disorder, and suggests that it may act as a trait marker.

Neurocognitive functioning in euthymic patients with bipolar disorder and unaffected relatives: A review of the literature

BACKGROUND

Neurocognitive deficits are present in bipolar disorder (BD) patients and their unaffected (nonbipolar) relatives, but it is not clear which domains are most often impaired and the extent of the impairment resulting from shared genetic factors. In this literature review, we address these issues and identify specific neurocognitive tasks most sensitive to cognitive deficits in patients and unaffected relatives.

METHOD

We conducted a systematic review in Web of Science, PubMed/Medline and PsycINFO databases.

RESULTS

Fifty-one articles assessing cognitive functioning in BD patients (23 studies) and unaffected relatives (28 studies) were examined. Patients and, less so, relatives show impairments in attention, processing speed, verbal learning/memory, and verbal fluency.

CONCLUSION

Studies were more likely to find impairment in patients than relatives, suggesting that some neurocognitive deficits may be a result of the illness itself and/or its treatment. However, small sample sizes, differences among relatives studied (e.g., relatedness, diagnostic status, age), and differences in assessment instruments may contribute to inconsistencies in reported neurocognitive performance among relatives. Additional studies addressing these issues are needed.

Random Projection for Fast and Efficient Multivariate Correlation Analysis of High-Dimensional Data: A New Approach

In recent years, the advent of great technological advances has produced a wealth of very high-dimensional data, and combining high-dimensional information from multiple sources is becoming increasingly important in an extending range of scientific disciplines. Partial Least Squares Correlation (PLSC) is a frequently used method for multivariate multimodal data integration. It is, however, computationally expensive in applications involving large numbers of variables, as required, for example, in genetic neuroimaging. To handle high-dimensional problems, dimension reduction might be implemented as pre-processing step. We propose a new approach that incorporates Random Projection (RP) for dimensionality reduction into PLSC to efficiently solve high-dimensional multimodal problems like genotype-phenotype associations. We name our new method PLSC-RP. Using simulated and experimental data sets containing whole genome SNP measures as genotypes and whole brain neuroimaging measures as phenotypes, we demonstrate that PLSC-RP is drastically faster than traditional PLSC while providing statistically equivalent results. We also provide evidence that dimensionality reduction using RP is data type independent. Therefore, PLSC-RP opens up a wide range of possible applications. It can be used for any integrative analysis that combines information from multiple sources.

Facial recognition deficits as a potential endophenotype in bipolar disorder

Bipolar disorder (BD) is considered a highly heritable and genetically complex disorder. Several cognitive functions, such as executive functions and verbal memory have been suggested as promising candidates for endophenotypes. Although there is evidence for deficits in facial emotion recognition in individuals with BD, studies investigating these functions as endophenotypes are rare. The current study investigates emotion recognition as a potential endophenotype in BD by comparing 36 BD participants, 24 of their 1st degree relatives and 40 healthy control participants in a computerised facial emotion recognition task. Group differences were evaluated using repeated measurement analysis of co-variance with age as a covariate. Results revealed slowed emotion recognition for both BD and their relatives. Furthermore, BD participants were less accurate than healthy controls in their recognition of emotion expressions. We found no evidence of emotion specific differences between groups. Our results provide evidence for facial recognition as a potential endophenotype in BD.

Affective Processing in Pediatric Bipolar Disorder and Offspring of Bipolar Parents

BACKGROUND

Bipolar disorder (BD) is characterized by biased processing of emotional information. However, little research in this area has been conducted in youth with BD and at-risk individuals. The goal of this study was to determine whether children with BD displayed comparable or more severe manifestations of this bias relative to offspring of parents with BD.

MATERIALS AND METHODS

The sample (n = 57 children and adolescents) included 18 individuals with BD (age: 13.63 ± 2.99; 8 females), 16 offspring of parents with BD (age: 11.83 ± 2.96; 9 females) and 23 healthy controls (HC) (age: 12.789 ± 3.087; 8 females). All participants performed the Affective Go/No-Go (AGN) and the Rapid Visual Processing (RVP) tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

Relative to HC, individuals with BD responded faster to correct trials and committed an elevated number of commission errors across all affective conditions of the AGN task. By contrast, BD offspring showed intact performance accuracy but quicker response times than HC. Post-hoc analyses revealed that this behavioral pattern was observed in BD offspring with mental health problems but not in healthy BD offspring. Overall, mean reaction times and total number of errors in the RVP task were comparable across groups.

CONCLUSIONS

In line with previous findings, subjects with BD encountered difficulties in processing affective information. The tendency toward faster but accurate responses to affective stimuli observed in BD offspring may be a marker of attentional bias toward affective information and constitute a vulnerability marker for mood disorder.

Structural brain network analysis in families multiply affected with bipolar I disorder

Disrupted structural connectivity is associated with psychiatric illnesses including bipolar disorder (BP). Here we use structural brain network analysis to investigate connectivity abnormalities in multiply affected BP type I families, to assess the utility of dysconnectivity as a biomarker and its endophenotypic potential. Magnetic resonance diffusion images for 19 BP type I patients in remission, 21 of their first degree unaffected relatives, and 18 unrelated healthy controls underwent tractography. With the automated anatomical labelling atlas being used to define nodes, a connectivity matrix was generated for each subject. Network metrics were extracted with the Brain Connectivity Toolbox and then analysed for group differences, accounting for potential confounding effects of age, gender and familial association. Whole brain analysis revealed no differences between groups. Analysis of specific mainly frontal regions, previously implicated as potentially endophenotypic by functional magnetic resonance imaging analysis of the same cohort, revealed a significant effect of group in the right medial superior frontal gyrus and left middle frontal gyrus driven by reduced organisation in patients compared with controls. The organisation of whole brain networks of those affected with BP I does not differ from their unaffected relatives or healthy controls. In discreet frontal regions, however, anatomical connectivity is disrupted in patients but not in their unaffected relatives.

Bipolar disorder: Functional neuroimaging markers in relatives

Neural models of anatomical and functional alterations have been proposed for bipolar disorders (BD). However, studies in affected patients do not allow disentangling alterations linked to the liability to BD from those associated with the evolution, medication and comorbidities of BD. Explorations in high risk subjects allow the study of these risk markers. We reported and summarized all functional magnetic resonance imaging (fMRI) studies focusing on first-degree relatives of BD patients. We found 29 studies reporting neural correlates of working memory (WM), emotional processing, executive functions and resting state in relatives of BD patients, compared to healthy subjects. Overall, the same regions that have been involved in patients, such as the inferior frontal gyrus and limbic areas, seem to be functionally altered in high-risk subjects. We conclude that the same brain regions already implicated in the pathophysiology of the disease such as the amygdala are also associated with the risk of BD. However longitudinal studies are required to understand their implication in the transition to BD.

Emotion Recognition Ability Test Using JACFEE Photos: A Validity/Reliability Study of a War Veterans' Sample and Their Offspring

Emotion recognition is very important for social interaction. Several mental disorders influence facial emotion recognition. War veterans and their offspring are subject to an increased risk of developing psychopathology. Emotion recognition is an important aspect that needs to be addressed in this population. To our knowledge, no test exists that is validated for use with war veterans and their offspring. The current study aimed to validate the JACFEE photo set to study facial emotion recognition in war veterans and their offspring. The JACFEE photo set was presented to 135 participants, comprised of 62 male war veterans and 73 war veterans’ offspring. The participants identified the facial emotion presented from amongst the possible seven emotions that were tested for: anger, contempt, disgust, fear, happiness, sadness, and surprise. A loglinear model was used to evaluate whether the agreement between the intended and the chosen emotions was higher than the expected. Overall agreement between chosen and intended emotions was 76.3% (Cohen kappa = 0.72). The agreement ranged from 63% (sadness expressions) to 91% (happiness expressions). The reliability by emotion ranged from 0.617 to 0.843 and the overall JACFEE photo set Cronbach alpha was 0.911. The offspring showed higher agreement when compared with the veterans (RR: 41.52 vs 12.12, p < 0.001), which confirms the construct validity of the test. The JACFEE set of photos showed good validity and reliability indices, which makes it an adequate instrument for researching emotion recognition ability in the study sample of war veterans and their respective offspring.

Neural correlates of negative emotion processing in bipolar disorder

INTRODUCTION

Bipolar disorder type I (BD-I) is characterized by a severe impairment in emotional processing during both acute and euthymic phases of the illness. The aim of the present study was to investigate negative emotion processing in both euthymic patients and non-affected first-degree relatives, looking for state and trait markers of BD-I.

METHODS

22 healthy relatives of BD-I patients (mean age 31.5±7.3 years; 15 females), 23 euthymic BD-I patients (mean age 35.2±7.9 years; 14 females), and 24 matched controls (mean age 32.5±6.2 years; 16 females) performed an IAPS-based emotional task during 1.5T fMRI. They were required to identify vegetable items (targets) inside neutral or negative pictures.

RESULTS

Euthymic BD-I patients showed a significant reduced accuracy in target detection during both neutral and negative images presentation, whereas first-degree relatives performed similarly to normal comparisons. We found a reduced activation of Left precuneus during negative images condition in the patients only. By contrast, both patients and relatives hyperactivated the Left insula and hypoactivated the Right supramarginal gyrus with respect to controls. Moreover, relatives showed an increased activation of Right lingual gyrus and lower activation of pre-supplementary motor area and Right superior frontal gyrus.

CONCLUSIONS

During a negative emotion task, euthymic BD-I patients and non-affected first-degree relatives shared an abnormal activation of a limbic area (Left insula) coupled with a reduced activation of a parietal region (Right supramarginal gyrus), thus suggesting a trait-like anomalous processing of affective contents. On the other hand, functional abnormalities found only in unaffected relatives and not in patients and controls may correspond to resilience factors.

All the world's a (clinical) stage: rethinking bipolar disorder from a longitudinal perspective

Psychiatric disorders have traditionally been classified using a static, categorical approach. However, this approach falls short in facilitating understanding of the development, common comorbid diagnoses, prognosis and treatment of these disorders. We propose a 'staging' model of bipolar disorder that integrates genetic and neural information with mood and activity symptoms to describe how the disease progresses over time. From an early, asymptomatic, but 'at-risk' stage to severe, chronic illness, each stage is described with associated neuroimaging findings as well as strategies for mapping genetic risk factors. Integrating more biologic information relating to cardiovascular and endocrine systems, refining methodology for modeling dimensional approaches to disease and developing outcome measures will all be crucial in examining the validity of this model. Ultimately, this approach should aid in developing targeted interventions for each group that will reduce the significant morbidity and mortality associated with bipolar disorder.