Executive functioning but not IQ or illness severity predicts occupational status in bipolar disorder

Exploring cognitive characteristics and impairments in bipolar disorder: Insights from the BiDiLoS-Ng pilot study

Bipolar disorder (BD) is a leading cause of disability and is linked to cognitive and functional impairment, increased mortality from cardiometabolic disorders and bipolar disorder suicide. Few studies in sub-Saharan Africa have explored cognitive dysfunction in bipolar disorder. Our study explores the cognitive characteristics in a bipolar patient cohort in Nigeria and assesses its association with clinical and demographic variables. 40 participants from the Bipolar Disorder Longitudinal Study, at baseline, were included in the pilot study of the BiDiLos-Ng. Using a cross-sectional design, cognitive function was assessed using the Screen for Cognitive Impairment in Psychiatry. Multiple linear regression models were used to explore associations between dependent and independent variables. Cognitive impairment was present in 41% of the bipolar cohort, it was not associated with the frequency of mood episodes, and higher educational level was associated with higher verbal fluency test scores (p = 0.02). Being in employment (p = 0.03), younger age (p = 0.00), and lower YMRS score (p = 0.006) were associated with higher working memory test scores. The presence of mania symptoms during the euthymic phase of BD was associated with cognitive impairment. Executive function and working memory were linked to better academic and occupational attainment.

Understanding social and clinical associations with unemployment for people with schizophrenia and bipolar disorders: large-scale health records study

PURPOSE

People with severe mental illness (SMI) experience high levels of unemployment. We aimed to better understand the associations between clinical, social, and demographic inequality indicators and unemployment.

METHODS

Data were extracted from de-identified health records of people with SMI in contact with secondary mental health services in south London, UK. A Natural Language Processing text-mining application was applied to extract information on unemployment in the health records. Multivariable logistic regression was used to assess associations with unemployment, in people with SMI.

RESULTS

Records from 19,768 service users were used for analysis, 84.9% (n = 16,778) had experienced unemployment. In fully adjusted models, Black Caribbean and Black African service users were more likely to experience unemployment compared with White British service users (Black Caribbean: aOR 1.62, 95% CI 1.45-1.80; Black African: 1.32, 1.15-1.51). Although men were more likely to have experienced unemployment relative to women in unadjusted models (OR 1.36, 95% CI 1.26-1.47), differences were no longer apparent in the fully adjusted models (aOR 1.05, 95% CI 0.97-1.15). The presence of a non-affective (compared to affective) diagnosis (1.24, 1.13-1.35), comorbid substance use (2.02, 1.76-2.33), previous inpatient admissions (4.18, 3.71-4.70), longer inpatient stays (78 + days: 7.78, 6.34-9.54), and compulsory admissions (3.45, 3.04-3.92) were associated with unemployment, in fully adjusted models.

CONCLUSION

People with SMI experience high levels of unemployment, and we found that unemployment was associated with several clinical and social factors. Interventions to address low employment may need to also address these broader inequalities.

Association of Occupational Dysfunction and Hospital Admissions With Different Polygenic Profiles in Bipolar Disorder

OBJECTIVE

Many but not all persons with bipolar disorder require hospital care because of severe mood episodes. Likewise, some but not all patients experience long-term occupational dysfunction that extends beyond acute mood episodes. It is not known whether these dissimilar outcomes of bipolar disorder are driven by different polygenic profiles. Here, polygenic scores (PGSs) for major psychiatric disorders and educational attainment were assessed for associations with occupational functioning and psychiatric hospital admissions in bipolar disorder.

METHODS

A total of 4,782 patients with bipolar disorder and 2,963 control subjects were genotyped and linked to Swedish national registers. Longitudinal measures from at least 10 years of registry data were used to derive percentage of years without employment, percentage of years with long-term sick leave, and mean number of psychiatric hospital admissions per year. Ordinal regression was used to test associations between outcomes and PGSs for bipolar disorder, schizophrenia, major depressive disorder, attention deficit hyperactivity disorder (ADHD), and educational attainment. Replication analyses of hospital admissions were conducted with data from the Bipolar Disorder Research Network cohort (N=4,219).

RESULTS

Long-term sick leave and unemployment in bipolar disorder were significantly associated with PGSs for schizophrenia, ADHD, major depressive disorder, and educational attainment, but not with the PGS for bipolar disorder. By contrast, the number of hospital admissions per year was associated with higher PGSs for bipolar disorder and schizophrenia, but not with the other PGSs.

CONCLUSIONS

Bipolar disorder severity (indexed by hospital admissions) was associated with a different polygenic profile than long-term occupational dysfunction. These findings have clinical implications, suggesting that mitigating occupational dysfunction requires interventions other than those deployed to prevent mood episodes.

The clinical significance of emotional urgency in bipolar disorder: a scoping review

BACKGROUND

Emotional urgency, defined as a trait concept of emotion-based impulsivity, is at least moderately associated with general psychopathology. However, its clinical significance and associations with clinically relevant features of bipolar disorder remain unclear. This scoping review aims address this gap by determining the extent of evidence in this niche scope of study.

METHODS

Evidence of between-group differences of positive and negative urgency, its associations with mood severity, and all peripheral associations related to illness and psychosocial outcomes were synthesized based on PRISMA checklists and guidelines for scoping reviews (PRISMA-ScR).

DESIGN

Electronic databases were searched for articles published between January 2001 and January 2024. A total of 1013 entries were gathered, and a total of 10 articles were included in the final selection after the removal of duplicates and ineligible articles.

RESULTS

Differences in urgency scores between bipolar disorder and healthy controls were large (Cohen's d ranged from 1.77 to 2.20). Negative urgency was at least moderately associated with overall trauma, emotional abuse, neglect, suicide ideation, neuroticism, and irritable/cyclothymic temperament, whereas positive urgency was at least moderately associated with various aspects of aggression and quality of life. Positive but not negative urgency was associated with quality of life in bipolar disorder.

CONCLUSION

Large between-group differences found for emotional urgency in bipolar disorder imply large clinical significance. Emotional urgency was associated with worse clinical features and outcomes. Given the high clinical heterogeneity of the disorder, emotional urgency may be an important phenotype indicative of greater disorder severity.

Slow-wave brain connectivity predicts executive functioning and group belonging in socially vulnerable individuals

Important efforts have been made to describe the neural and cognitive features of healthy and clinical populations. However, the neural and cognitive features of socially vulnerable individuals remain largely unexplored, despite their proneness to developing neurocognitive disorders. Socially vulnerable individuals can be characterised as socially deprived, having a low socioeconomic status, suffering from chronic social stress, and exhibiting poor social adaptation. While it is known that such individuals are likely to perform worse than their peers on executive function tasks, studies on healthy but socially vulnerable groups are lacking. In the current study, we explore whether neural power and connectivity signatures can characterise executive function performance in healthy but socially vulnerable individuals, shedding light on the impairing effects that chronic stress and social disadvantages have on cognition. We measured resting-state electroencephalography and executive functioning in 38 socially vulnerable participants and 38 matched control participants. Our findings indicate that while neural power was uninformative, lower delta and theta phase synchrony are associated with worse executive function performance in all participants, whereas delta phase synchrony is higher in the socially vulnerable group compared to the control group. Finally, we found that delta phase synchrony and years of schooling are the best predictors for belonging to the socially vulnerable group. Overall, these findings suggest that exposure to chronic stress due to socioeconomic factors and a lack of education are associated with changes in slow-wave neural connectivity and executive functioning.

Impact of cognitive reserve on bipolar disorder: a systematic review

Background

Cognitive reserve (CR) is a complex concept that includes premorbid IQ, years of education, and exposure to neuropsychological stimuli through work and leisure. Previous studies have suggested that CR has a positive impact on several aspects of bipolar disorder. Synthesizing the evidence to date is an important work in providing directions for future studies. The objectives of this systematic review to summary impact of CR on onsetting, relapsing bipolar episodes, buffering cognitive dysfunctions, and maintaining quality of life (QOL) in bipolar disorder.

Methods

Two researchers independently reviewed selected paper from three database as PubMed, PsychINFO, and Web of Science. The search keywords were "bipolar disorder" and "cognitive reserve." The selected studies were classified as the levels of evidence according to the criteria of the Oxford Center for Evidence- Based Medicine. The results of the selected studies were summarized according to the objectives.

Results

Thrity six studies were included in this review. People with high CR may have fewer bipolar episodes and alleviate cognitive impairments and dysfunction. CR may keep the functional level in patients with bipolar disorder.

Conclusion

The results of this systematic review suggest that CR may be involved in preventing relapse of bipolar episodes and may alleviate cognitive dysfunction. However, effect on prevention of onset-risk and relapse of bipolar episodes need further investigation in prospective studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021270293, the protocol was registered with PROSERO (CRD42021270293).

Comparison of verbal fluency performance in Kannada-speaking adults with and without euthymic bipolar disorder type 1

Individuals with euthymic bipolar disorder (BD) type I exhibit deficits in executive functions. Although less explored in the BD population, the tasks of verbal fluency (VF) have shown great potential in understanding semantic organization. This study provides an extensive exploration across the letter and semantic VF tasks in 27 demographically matched euthymic BD-I and healthy controls (HC). The groups were compared on measures of the total number of correct words (TNCW), temporal pattern analysis, number of clusters (NC), mean cluster size (MCS), number of switches (NS), and error pattern. An overall reduction in letter fluency scores (the TNCW, number of switches, and NC) as compared to semantic fluency scores was noted for both groups, with a significantly greater decrease in the BD-1 group. The MCS and temporal pattern were relatively similar across the two groups. The influence of education with no gender difference was observed between groups with error types prevalent in both groups. The study findings call attention toward assessing the VF performance in persons with BD in terms of error production and the strategies employed (clustering-switching).

Association of premorbid intelligence with level of functioning and illness severity in bipolar disorder

BACKGROUND

Bipolar disorder is a severe psychiatric syndrome defined by periodic mood shifts. Patients with bipolar disorder show cognitive impairments relative to healthy controls. The risk of developing schizophrenia, and partially also bipolar disorder, has previously been shown to increase with lower premorbid intelligence. It is not known if premorbid intelligence is associated with level of functioning and illness severity of people having developed bipolar disorder.

METHODS

We used multiple linear and ordinal regression to analyze how premorbid intelligence, as measured at conscription, associate with functional outcome and illness severity in Swedish male bipolar disorder patients (n = 788).

RESULTS

We found that lower premorbid intelligence is associated with lower percentage of time in work, after adjusting for age and bipolar subtype, and correcting for multiple comparisons. We also found a strong negative association with the total number of inpatient episodes and psychiatric comorbidity, but not with interepisodic remission, treatment with psychotherapy or lithium or the presence of any complicating socioeconomical factors. Adjusting for confounding genetic factors using polygenic risk scores for bipolar disorder and schizophrenia had no effect on the associations.

LIMITATIONS

This study lacks females and controls and may thus have lower generalizability.

CONCLUSION

In conclusion, premorbid intelligence is associated with both level of functioning and illness severity as well as comorbidity in bipolar disorder patients. Further research is needed to develop targeted interventions for this subgroup of bipolar disorder patients.

Self- and informant-reported executive function in young adults operated for atrial or ventricular septal defects in childhood

BACKGROUND

Adults with simple congenital heart defects (CHD) have increased risk of neurodevelopmental challenges including executive dysfunction. It is unknown if the executive dysfunction is universal or if it is driven by dysfunction in specific clinical subscales and how it might affect psychosocial aspects of everyday life.

METHODS

The self-reported and informant-reported executive function of adults with an average age of 26 ± 5 (range 18-41) who underwent childhood surgery for atrial septal defects (n = 34) or ventricular septal defects (n = 32) and matched controls (n = 40) were evaluated using the Behavior Rating Inventory of Executive Functions - Adult version (BRIEF-A).

RESULTS

The CHD group reported having more executive dysfunction than controls in all BRIEF-A clinical subscales (p < 0.020) and more than their informants reported on their behalf (p < 0.006). The CHD group had received three times more special teaching (44% compared to 16%) and pedagogical psychological counselling (14% compared to none) and had a three times higher occurrence of psychiatric disorders than controls (33% compared to 11%). Lower educational levels and psychiatric disorders were associated with higher BRIEF-A scores (p < 0.03).

CONCLUSIONS

Adults operated for septal defects in childhood report more challenges with all aspects of the executive functions than controls and more than relatives are aware of.

Psychotic symptoms in bipolar disorder and their impact on the illness: A systematic review

BACKGROUND

Lifetime psychotic symptoms are present in over half of the patients with bipolar disorder (BD) and can have an adverse effect on its course, outcome, and treatment. However, despite a considerable amount of research, the impact of psychotic symptoms on BD remains unclear, and there are very few systematic reviews on the subject.

AIM

To examine the extent of psychotic symptoms in BD and their impact on several aspects of the illness.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. An electronic literature search of six English-language databases and a manual search was undertaken to identify published articles on psychotic symptoms in BD from January 1940 to December 2021. Combinations of the relevant Medical Subject Headings terms were used to search for these studies. Articles were selected after a screening phase, followed by a review of the full texts of the articles. Assessment of the methodological quality of the studies and the risk of bias was conducted using standard tools.

RESULTS

This systematic review included 339 studies of patients with BD. Lifetime psychosis was found in more than a half to two-thirds of the patients, while current psychosis was found in a little less than half of them. Delusions were more common than hallucinations in all phases of BD. About a third of the patients reported first-rank symptoms or mood-incongruent psychotic symptoms, particularly during manic episodes. Psychotic symptoms were more frequent in bipolar type I compared to bipolar type II disorder and in mania or mixed episodes compared to bipolar depression. Although psychotic symptoms were not more severe in BD, the severity of the illness in psychotic BD was consistently greater. Psychosis was usually associated with poor insight and a higher frequency of agitation, anxiety, and hostility but not with psychiatric comorbidity. Psychosis was consistently linked with increased rates and the duration of hospitalizations, switching among patients with depression, and poorer outcomes with mood-incongruent symptoms. In contrast, psychosis was less likely to be accompanied by a rapid-cycling course, longer illness duration, and heightened suicidal risk. There was no significant impact of psychosis on the other parameters of course and outcome.

CONCLUSION

Though psychotic symptoms are very common in BD, they are not always associated with an adverse impact on BD and its course and outcome.

The relations between executive functions and occupational functioning in individuals with bipolar disorder: a scoping review

BACKGROUND

Patients with bipolar disorder experience impairments in their occupational functioning, despite remission of symptoms. Previous research has shown that neurocognitive deficits, especially deficits in executive functions, may persist during euthymia and are associated with diminished occupational functioning.

OBJECTIVES

The aim of this scoping review was to identify published studies that report on the relationships between executive functions and occupational functioning in BD to review current knowledge and identify knowledge gaps. In addition to traditional neuropsychological approaches, we aimed to describe executive functioning from a self-regulation perspective, including emotion regulation.

METHODS

We applied the methodological framework as described by Arksey and O'Malley (Int J Soc Res Methodol Theory Pract 8:19-32, 2005) and Levac et al. (Implement Sci 5:1-9, 2010). We searched PubMed and psycINFO for literature up to November 2021, after which we screened papers based on inclusion criteria. Two reviewers independently performed the screening process, data charting process, and synthesis of results.

RESULTS

The search yielded 1202 references after deduplication, of which 222 remained after initial screening. The screening and inclusion process yielded 82 eligible papers in which relationships between executive functions and occupational functioning are examined.

CONCLUSION

Neurocognitive deficits, including in executive functions and self-regulation, are associated with and predictive of diminished occupational functioning. Definitions and measurements for neurocognitive functions and occupational functioning differ greatly between studies, which complicates comparisons. Studies on functional remediation show promising results for improving occupational functioning in patients with BD. In research and clinical practice more attention is needed towards the quality of work functioning and the various contexts in which patients with BD experience deficits.

Aberrant Functional Connectivity of Sensorimotor Network and Its Relationship With Executive Dysfunction in Bipolar Disorder Type I

Background

The key pathophysiological mechanism of executive dysfunction in patients with bipolar disorder type I (BD-I) is still unclear. Previous studies have demonstrated that it may be related to the disbalance of the sensory motor network (SMN).

Objective

This study was designed to explore the aberrant functional connectivity (FC) of SMN in BD-I patients and its potential associations with executive dysfunction.

Methods

Eighteen BD-I patients and 20 healthy controls (HCs) underwent resting-state fMRI scans. The intranetwork and internetwork functional connectivities of SMN were extracted by independent component analysis (ICA). Clinical symptoms were assessed by the Bech-Rafaelsen Mania Rating Scale (BRMS) and Positive and Negative Syndrome Scale (PANSS). Executive function was measured by digit span tasks and a verbal fluency test. Finally, linear regression and correlation analyses were applied to measure the potential associations between clinical symptoms, intranetwork and internetwork functional connectivities, and executive function performance.

Results

(1) Patients with BD-I showed increased connectivity in the right paracentral lobule and the right postcentral gyrus within the SMN, and the increased connectivity value was positively correlated with the BRMS score (P < 0.05) but negatively correlated with digit span forward scores (P < 0.05). (2) Compared with HC, the connectivity value increased between the SMN and dorsal attention network (DAN) (P < 0.01) and between the default mode network (DMN) and DAN (P < 0.05) but decreased between the DAN and auditory network (AN) (P < 0.05) and between the SMN and DMN (P < 0.01) in patients with BD-I. (3) Digit span forward scores and education of all participants were negatively correlated with FC between SMN and DAN. Age of all subjects was positively correlated with FC between SMN and DMN.

Conclusion

Our findings suggest that the sensorimotor network of BD-I has abnormal functional connections within and between networks, and the abnormal FC value correlated with clinical symptoms and executive function, which provide new information for exploring the neural physiopathology of executive dysfunction in BD-I patients.

The impact of bipolar spectrum disorders on professional functioning: A systematic review

AIMS

The impact of bipolar spectrum (BS) disorders on professional functioning has not been systematically reviewed yet. Since even subsyndromal symptoms may disturb functioning, the determination of the prognostic value of the spectrum of bipolarity for employment seems extremely relevant. The aim of this study was to assess the impact of BS disorders on professional functioning.

MATERIALS AND METHODS

A systematic review of the literature (namely, cohort and cross-sectional studies) investigating a link between BS disorders and employment was performed in accordance with PRISMA guidelines. BS was defined based on the concept of two-dimensional BS by Angst. Occupational outcomes and factors affecting employment were evaluated as well.

RESULTS

Seventy-four studies were included. All disorders comprising BS had a negative impact on occupational status, work performance, work costs, and salary, with the greatest unfavorable effect reported by bipolar disorder (BD), followed by borderline personality disorder (BPD), major depressive disorder (MDD), and dysthymia. Employment rates ranged from 40 to 75% (BD), 33 to 67% (BPD), 61 to 88% (MDD), and 86% (dysthymia). The factors affecting employment most included: cognitive impairments, number/severity of symptoms, namely, subsyndromal symptoms (mainly depressive), older age, education, and comorbidity (substance abuse, personality disorders, anxiety, depression, ADHD, PTSD).

CONCLUSION

Bipolar spectrum symptoms exert a negative impact on professional functioning. Further evaluation of affecting factors is crucial for preventing occupational disability.

Relationship Between Employment Status and Unstable Periods in Outpatients with Bipolar Disorder: A Multicenter Treatment Survey for Bipolar Disorder in Psychiatric Outpatient Clinics (MUSUBI) Study

PURPOSE

To clarify the relationship between the length of unstable periods and employment status of patients with bipolar disorder.

PATIENTS AND METHODS

Medical records of outpatients with bipolar disorder who visited 176 member clinics of the Japanese Association of Neuro-Psychiatric Clinics were investigated during September-October 2016, and details of their medical care and employment were surveyed using a questionnaire. The odds ratios (ORs) of length of unstable period and unemployment were analyzed with a logistic regression model.

RESULTS

The study included 816 patients, of whom 707 were employed full-time (continuous employment) and 70 were unemployed (loss of employment). Univariate analysis showed that ORs were statistically significant for patients who were unstable for "almost all" of the year (OR = 10.4 [4.48-24.28] p < 0.001), but not for "few" unstable periods (OR = 1.06 [0.56-1.98] p = 0.849) and for "significant" unstable periods (OR = 1.65 [0.73-3.74] p = 0.231) were not significantly different. Multivariate analysis showed that ORs were statistically "significant" for patients who were unstable for "almost all" (OR = 12.1 [4.37-33.3] p < 0.001), but not for "few" unstable periods (OR = 1.07 [0.55-2.07] p = 0.846) and for "significant" unstable periods (OR = 1.62 [0.66-3.98] p = 0.290) did not differ significantly.

CONCLUSION

Patients with bipolar disorder with a long unstable period were associated with a higher risk of unemployment.

Sustained Attention and Working Memory Predict the Number of Days on Health-Related Benefits in the Year Following Occupational Rehabilitation

Purpose The objective of this study was to investigate the association between cognitive and emotional functioning and the number of days on health-related benefits such as sick leave, work assessment allowance and disability pension. We investigated whether cognitive and emotional functioning at the start of rehabilitation and the change from the start to the end of rehabilitation predicted the number of days on health-related benefits in the year after occupational rehabilitation. Methods A sample of 317 individuals (age 19-67 years), mainly diagnosed with a musculoskeletal or mental and behavioural ICD-10 disorder, participated. The sample was stratified depending on the benefit status in the year before rehabilitation. Those receiving health-related benefits for the full year comprised the work assessment allowance and disability pension (WAA) group and those receiving benefits for less than a year comprised the sick leave (SL) group. The participants were administered cognitive and emotional computerised tests and work and health questionnaires at the beginning and end of rehabilitation. The cumulative number of days on health-related benefits during 12 months after rehabilitation was the primary outcome variable and age, gender, educational level, subjective health complaints, anxiety, and depression were controlled for in multiple regression analyses. Results The WAA group (n = 179) was significantly impaired at baseline compared to the SL group (n = 135) in focused attention and executive function, and they also scored worse on work and health related variables. Higher baseline scores and change scores from the start to the end of rehabilitation, for sustained attention, were associated with fewer number of health-related benefit days in the WAA group, while higher baseline scores for working memory were associated with fewer number of health-related benefit days in the SL group. Conclusions New knowledge about attention and memory and return to work in individuals with different benefit status may pave the way for more targeted programme interventions. Rehabilitation programmes could benefit from designing interventions that respectively improve sustain attention and working memory related to working life in individuals on sick leave or work assessment allowance and disability pension.

Evidence for avolition in bipolar disorder? A 30-day ecological momentary assessment comparison of daily activities in bipolar disorder and schizophrenia

OBJECTIVES

Disability is common in bipolar disorder (BD) and predicted by persistent sadness. We used ecological momentary assessment (EMA) to examine daily activities in people with BD and schizophrenia. We classified activities as productive, unproductive, or passive recreation, relating them to momentary sadness, location, and social context.

METHODS

71 people with BD and 102 people with schizophrenia were sampled 3 times/day for 30 days with an EMA survey. Each survey asked where they were, with whom, what they were doing, and if they were sad.

RESULTS

People with BD were home more than 50% of the time. There were no differences in prevalence of activity types across diagnoses. People with BD were less likely to report only one activity since the prior survey, but the most surveys still reported only one. For both groups, sadness and being home and alone since the last survey was associated with less productive activity and more passive recreation.

CONCLUSIONS

Participants with BD and schizophrenia manifested high levels of unproductive and passive activities, predicted by momentary sadness. These activity patterns are consistent with descriptions of avolition and they minimally differentiated people with BD and schizophrenia. Previous reports of negative symptoms in BD may have been identifying these behaviors.

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.