Differences between bipolar I and bipolar II disorders in clinical features, comorbidity, and family history

Abnormal functional connectivity of the intrinsic networks in adolescent bipolar I versus bipolar II disorder

BACKGROUND

The symptoms of pediatric bipolar disorder (PBD)-I and PBD-II differ, but accurate identification at an early stage is difficult and may prevent effective treatment of this disorder. Therefore, it is urgent to elucidate a biological marker based on objective imaging indicators to help distinguish the two. Therefore, this research aims to compare the functional connectivity between PBD-I patient and PBD-II patient in different brain networks.

METHODS

Our study enrolled 31 PBD-I and 23 PBD-II patients from 12 to 17 years of age. They were analyzed by resting state-functional connectivity through Independent component analysis (ICA).

RESULTS

We found differences between PBD-I and PBD-II in functional connectivity of the default network, frontoparietal network, salience network and limbic system. In addition, the clinical features, cognitive functions are associated with the functional connectivity of the intrinsic networks in PBD-I and PBD-II separately.

CONCLUSION

This research is the first to find differences in functional connectivity between PBD-I and PBD-II, suggesting that abnormality of the functional connectivity within large networks may be biomarkers that help differentiate PBD-I from PBD-II in the future.

Genomic SEM applied to explore etiological divergences in bipolar subtypes

BACKGROUND

Bipolar disorder (BD) is an overarching diagnostic class defined by the presence of at least one prior manic episode (BD I) or both a prior hypomanic episode and a prior depressive episode (BD II). Traditionally, BD II has been conceptualized as a less severe presentation of BD I, however, extant literature to investigate this claim has been mixed.

METHODS

We apply genomic structural equation modeling (Genomic SEM) to investigate divergent genetic pathways across BD's two major subtypes using the most recent GWAS summary statistics from the PGC. We begin by identifying divergences in genetic correlations across 98 external traits using a Bonferroni-corrected threshold. We also use a theoretically informed follow-up model to examine the extent to which the genetic variance in each subtype is explained by schizophrenia and major depression. Lastly, transcriptome-wide SEM (T-SEM) was used to identify neuronal gene expression patterns associated with BD subtypes.

RESULTS

BD II was characterized by significantly larger genetic overlap across non-psychiatric medical and internalizing traits (e.g. heart disease, neuroticism, insomnia), while stronger associations for BD I were absent. Consistent with these findings, follow-up modeling revealed a substantial major depression component for BD II. T-SEM results revealed 35 unique genes associated with shared risk across BD subtypes.

CONCLUSIONS

Divergent patterns of genetic relationships across external traits provide support for the distinction of the bipolar subtypes. However, our results also challenge the illness severity conceptualization of BD given stronger genetic overlap across BD II and a range of clinically relevant traits and disorders.

Differential characteristics of bipolar I and II disorders: a retrospective, cross-sectional evaluation of clinical features, illness course, and response to treatment

BACKGROUND

The distinction between bipolar I and bipolar II disorder and its treatment implications have been a matter of ongoing debate. The aim of this study was to examine differences between patients with bipolar I and II disorders with particular emphasis on the early phases of the disorders.

METHODS

808 subjects diagnosed with bipolar I (N = 587) or bipolar II disorder (N = 221) according to DSM-IV criteria were recruited between April 1994 and March 2022 from tertiary-level mood disorder clinics. Sociodemographic and clinical variables concerning psychiatric and medical comorbidities, family history, illness course, suicidal behavior, and response to treatment were compared between the bipolar disorder types.

RESULTS

Bipolar II disorder patients were more frequently women, older, married or widowed. Bipolar II disorder was associated with later "bipolar" presentation, higher age at first (hypo)mania and treatment, less frequent referral after a single episode, and more episodes before lithium treatment. A higher proportion of first-degree relatives of bipolar II patients were affected by major depression and anxiety disorders. The course of bipolar II disorder was typically characterized by depressive onset, early depressive episodes, multiple depressive recurrences, and depressive predominant polarity; less often by (hypo)mania or (hypo)mania-depression cycles at onset or during the early course. The lifetime clinical course was more frequently rated as chronic fluctuating than episodic. More patients with bipolar II disorder had a history of rapid cycling and/or high number of episodes. Mood stabilizers and antipsychotics were prescribed less frequently during the early course of bipolar II disorder, while antidepressants were more common. We found no differences in global functioning, lifetime suicide attempts, family history of suicide, age at onset of mood disorders and depressive episodes, and lithium response.

CONCLUSIONS

Differences between bipolar I and II disorders are not limited to the severity of (hypo)manic syndromes but include patterns of clinical course and family history. Caution in the use of potentially mood-destabilizing agents is warranted during the early course of bipolar II disorder.

Prevalence of eating disorders in patients with bipolar disorder: a scoping review of the literature

BACKGROUND

Eating disorder (ED) and bipolar disorder (BD) exhibit certain phenomenological similarities rooted in eating behavior and emotional regulation. However, despite the growing body of research on the comorbidity of ED and BD, scientific data on the concurrent course of these disorders has remained poorly systematized.

AIM

To conduct a scoping review of published data on the prevalence of various types of ED among patients with BD types I and II in the context of the sex and clinical features of the concurrent course of these disorders.

METHODS

The analysis was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. The search was conducted in the MEDLINE electronic database. Studies were included if they were focused samples of patients diagnosed with BD and ED, and the Diagnostic and Statistical Manual of Mental Disorders, fourth and fifth editions (DSM-IV, DSM-5), or International Statistical Classification of Diseases and Related Health Problems, tenth Revision (ICD-10), were used for the verification of the ED and BD diagnoses. The descriptive analysis method was used to summarize the review findings.

RESULTS

A total of 41 studies were selected for the review. Lifetime ED in patients with BD ranged from 2.2% to 31.1%, and the prevalence rates of BD among patients with ED varied from 11.3% to 68.1%. ED nominally had a higher prevalence among individuals with BD type II and females. Additionally, the presence of ED in patients with BD was associated with earlier onset of mood disorder, a higher number of depressive episodes, higher levels of atypical depressive symptoms, suicide attempts, as well as a higher frequency of comorbid obsessive-compulsive and anxiety disorders, addictions, and various metabolic disorders.

CONCLUSION

Despite the high degree of volatility in the results, the prevalence rates of a concurrent course of ED and BD are rather high. For this reason, screening for ED in patients with BD and vice versa holds significant value in the accurate diagnosis and selection of the most effective therapy. The patterns of comorbidity among different types of ED and BD, depending on gender, need further exploration in future research.

Status of Type II vs. Type I Bipolar Disorder: Systematic Review with Meta-Analyses

LEARNING OBJECTIVES AFTER PARTICIPATING IN THIS CME ACTIVITY, THE PSYCHIATRIST SHOULD BE BETTER ABLE TO

• Analyze and compare the different bipolar disorder (BD) types.• Identify markers that distinguish BD types and explain how the DSM-IV defines the disorder.

ABSTRACT

Since the status of type II bipolar disorder (BD2) as a separate and distinct form of bipolar disorder (BD) remains controversial, we reviewed studies that directly compare BD2 to type I bipolar disorder (BD1). Systematic literature searching yielded 36 reports with head-to-head comparisons involving 52,631 BD1 and 37,363 BD2 patients (total N = 89,994) observed for 14.6 years, regarding 21 factors (with 12 reports/factor). BD2 subjects had significantly more additional psychiatric diagnoses, depressions/year, rapid cycling, family psychiatric history, female sex, and antidepressant treatment, but less treatment with lithium or antipsychotics, fewer hospitalizations or psychotic features, and lower unemployment rates than BD1 subjects. However, the diagnostic groups did not differ significantly in education, onset age, marital status, [hypo]manias/year, risk of suicide attempts, substance use disorders, medical comorbidities, or access to psychotherapy. Heterogeneity in reported comparisons of BD2 and BD1 limits the firmness of some observations, but study findings indicate that the BD types differ substantially by several descriptive and clinical measures and that BD2 remains diagnostically stable over many years. We conclude that BD2 requires better clinical recognition and significantly more research aimed at optimizing its treatment.

Genomic SEM Applied to Explore Etiological Divergences in Bipolar Subtypes

Background

Bipolar Disorder (BD) is an overarching diagnostic class defined by the presence of at least one prior manic episode (BD I) or both a prior hypomanic episode and a prior depressive episode (BD II). Traditionally, BD II has been conceptualized as a less severe presentation of BD I, however, extant literature to investigate this claim has been mixed.

Methods

We apply Genomic Structural Equation Modeling (Genomic SEM) to investigate divergent genetic pathways across BD's two major subtypes using the most recent GWAS summary statistics from the PGC. We begin by identifying divergences in genetic correlations across 89 external traits using a Bonferroni corrected threshold. We also use a theoretically informed follow-up model to examine the extent to which the genetic variance in each subtype is explained by schizophrenia and major depression. Lastly, Transcriptome-wide SEM (T-SEM) was used to identify gene expression patterns associated with the BD subtypes.

Results

BD II was characterized by significantly larger genetic overlap with internalizing traits (e.g., neuroticism, insomnia, physical inactivity), while significantly stronger associations for BD I were limited. Consistent with these findings, the follow-up model revealed a much larger major depression component for BD II. T-SEM results revealed 41 unique genes associated with risk pathways across BD subtypes.

Conclusions

Divergent patterns of genetic relationships across external traits provide support for the distinction of the bipolar subtypes. However, our results also challenge the illness severity conceptualization of BD given stronger genetic overlap across BD II and a range of clinically relevant traits and disorders.

Bipolar I and bipolar II subtypes in older age: Results from the Global Aging and Geriatric Experiments in Bipolar Disorder (GAGE-BD) project

OBJECTIVES

The distinction between bipolar I disorder (BD-I) and bipolar II disorder (BD-II) has been a topic of long-lasting debate. This study examined differences between BD-I and BD-II in a large, global sample of OABD, focusing on general functioning, cognition and somatic burden as these domains are often affected in OABD.

METHODS

Cross-sectional analyses were conducted with data from the Global Aging and Geriatric Experiments in Bipolar Disorder (GAGE-BD) database. The sample included 963 participants aged ≥50 years (714 BD-I, 249 BD-II). Sociodemographic and clinical factors were compared between BD subtypes including adjustment for study cohort. Multivariable analyses were conducted with generalized linear mixed models (GLMMs) and estimated associations between BD subtype and (1) general functioning (GAF), (2) cognitive performance (g-score) and (3) somatic burden, with study cohort as random intercept.

RESULTS

After adjustment for study cohort, BD-II patients more often had a late onset ≥50 years (p = 0.008) and more current severe depression (p = 0.041). BD-I patients were more likely to have a history of psychiatric hospitalization (p < 0.001) and current use of anti-psychotics (p = 0.003). Multivariable analyses showed that BD subtype was not related to GAF, cognitive g-score or somatic burden.

CONCLUSION

BD-I and BD-II patients did not differ in terms of general functioning, cognitive impairment or somatic burden. Some clinical differences were observed between the groups, which could be the consequence of diagnostic definitions. The distinction between BD-I and BD-II is not the best way to subtype OABD patients. Future research should investigate other disease specifiers in this population.

A systematic review and meta-analysis of global and social functioning among people at risk of bipolar disorder

BACKGROUND

Functional status could predict development of bipolar disorder (BD) or have clinical significance. The relationship between BD risk and functioning is poorly understood. We undertook a systematic review examining the global and social functioning of those at risk for BD.

METHODS

We examined observational studies comparing a risk sample with healthy controls or full-threshold BD participants, using measures of global or social functioning. Risk status included family history of BD, meeting risk criteria, or having prodromal symptomatology, or premorbid functioning of persons with BD. Medline, PsycINFO, and Embase were searched. The Newcastle-Ottawa Scale for Cross-Sectional Studies was used to assess quality. Meta-analyses were performed where possible.

RESULTS

7215 studies were screened and 40 studies were included (8474 participants). Risk samples had poorer functioning than controls, and superior functioning to participants with BD. Meta-analysis indicated poorer global functioning among persons with familial risk compared to healthy controls (mean global functional difference: 5.92; 95 % confidence interval: 7.90, 3.95; mean premorbid functioning difference: 2.31; 95 % confidence interval: 0.70, 3.92). Studies with higher proportions of female participants had slightly poorer global functioning. High heterogeneity was attributable functional measures and potentially functionally differential subgroups within the risk samples.

LIMITATIONS

Broader measures of functioning, such as neurocognition and behavioural measures, were excluded. Measures of global functioning are limited by conflating functioning and symptoms.

CONCLUSIONS

Functioning in the BD risk populations is intermediate to that of healthy controls and persons with BD, indicating their value in definitions of BD risk, in itself a likely heterogeneous state.

Sleep spindles in people with schizophrenia, schizoaffective disorders or bipolar disorders: a pilot study in a general population-based cohort

BACKGROUND

Sleep spindles have been involved in sleep stabilization and sleep-related memory mechanisms and their deficit emerged as possible biomarker in schizophrenia. However, whether this sleep phenotype is also present in other disorders that share psychotic symptoms remains unclear. To address this gap, we assessed sleep spindles in participants of a prospective population-based cohort who underwent psychiatric assessment (CoLaus|PsyCoLaus) and polysomnographic recording (HypnoLaus).

METHODS

Sleep was recorded using ambulatory polysomnography in participants (N = 1037) to the PsyCoLaus study. Sleep spindle parameters were measured in people with a lifelong diagnosis of schizophrenia (SZ), schizoaffective depressive (SAD), schizoaffective manic (SAM), bipolar disorder type I (BP-I) and type II (BP-II). The associations between lifetime diagnostic status (independent variables, SZ, SAD, SAM, BPD-I, BPD-II, controls) and spindle parameters (dependent variables) including density, duration, frequency and maximum amplitude, for all (slow and fast), slow- and fast-spindle were assessed using linear mixed models. Pairwise comparisons of the different spindle parameters between the SZ group and each of the other psychiatric groups was performed using a contrast testing framework from our multiple linear mixed models.

RESULTS

Our results showed a deficit in the density and duration of sleep spindles in people with SZ. They also indicated that participants with a diagnosis of SAD, SAM, BP-I and BP-II exhibited different sleep spindle phenotypes. Interestingly, spindle densities and frequencies were different in people with a history of manic symptoms (SAM, BP-I, and BP-II) from those without (SZ, SAD).

CONCLUSIONS

Although carried out on a very small number of participants due to the low prevalence of these disorders in general population, this pilot study brought new elements that argued in favor of a deficit of sleep spindles density and duration in people with schizophrenia. In addition, while we could expect a gradual change in intensity of the same sleep spindle parameters through psychotic diagnoses, our results seem to indicate a more complex situation in which the frequency of sleep spindles might be more impacted by diagnoses including a history of mania or hypomania. Further studies with a larger number of participants are required to confirm these effects.

Heterogeneous early illness courses of Korean patients with bipolar disorders: replication of the staging model

BACKGROUND

Clinical staging of bipolar disorder (BD) requires application of real-world data, as the next step in hypothesis. This study used the staging model to analyze the long-term course of BD in Korean patients based on clinical features and treatment responses to map the progression of bipolar illness from its early phase after the onset of illness.

METHODS

A total of 136 patients diagnosed with BD-I (n = 62) or BD-II (n = 74) were recruited. Their progressive stages were retrospectively evaluated. A multi-state model was used to calculate the probability of progression to each stage. Hazard ratios of covariates expected to influence different courses of BD were calculated. Using the Alda score, long-term responses to mood stabilizers depending on the current stage were compared.

RESULTS

Several sub-populations showed varied courses during the first five years after the onset of illness, with 41.5% remaining in stage 2 and 53% progressing to higher stages with shortened time for transition. Profiles of patients with BD-I and BD-II were different, suggesting biologically distinct groups. Comorbid psychiatric disorders, such as obsessive-compulsive disorder (OCD) and bulimia nervosa (BN) were associated with a recurrent course (stage 3a or 3b) or a malignant course (stage 3c or 4). Early age of onset, shorter duration of illness, older age at the start of medication, and poor response to lithium affected the illness progression.

CONCLUSION

We were able to apply the stage model based on episode recurrence patterns in early illness courses of Korean patients with BD. The stage progression pattern differed from the early phase in BD-I and BD-II patients. Psychotic comorbidity, age at onset, age at starting psychiatric treatment showed associations with the illness progression.

Altered dynamic amplitude of low-frequency fluctuation between bipolar type I and type II in the depressive state

BACKGROUND

Bipolar disorder is a chronic and highly recurrent mental disorder that can be classified as bipolar type I (BD I) and bipolar type II (BD II). BD II is sometimes taken as a milder form of BD I or even doubted as an independent subtype. However, the fact that symptoms and severity differ in patients with BD I and BD II suggests different pathophysiologies and underlying neurobiological mechanisms. In this study, we aimed to explore the shared and unique functional abnormalities between subtypes.

METHODS

The dynamic amplitude of low-frequency fluctuation (dALFF) was performed to compare 31 patients with BD I, 32 with BD II, and 79 healthy controls (HCs). Global dALFF was calculated using sliding-window analysis. Group differences in dALFF among the 3 groups were compared using analysis of covariance (ANCOVA), with covariates of age, sex, years of education, and mean FD, and Bonferroni correction was applied for post hoc analysis. Pearson and Spearman's correlations were conducted between clusters with significant differences and clinical features in the BD I and BD II groups, after which false error rate (FDR) was used for correction.

RESULTS

We found a significant decrease in dALFF values in BD patients compared with HCs in the following brain regions: the bilateral-side inferior frontal gyrus (including the triangular, orbital, and opercular parts), inferior temporal gyrus, the medial part of the superior frontal gyrus, middle frontal gyrus, anterior cingulum, insula gyrus, lingual gyrus, calcarine gyrus, precuneus gyrus, cuneus gyrus, left-side precentral gyrus, postcentral gyrus, inferior parietal gyrus, superior temporal pole gyrus, middle temporal gyrus, middle occipital gyrus, superior occipital gyrus and right-side fusiform gyrus, parahippocampal gyrus, hippocampus, middle cingulum, orbital part of the medial frontal gyrus and superior frontal gyrus. Unique alterations in BD I were observed in the right-side supramarginal gyrus and postcentral gyrus. In addition, dALFF values in BD II were significantly higher than those in BD I in the right superior temporal gyrus and middle temporal gyrus. The variables of dALFF correlated with clinical characteristics differently according to the subtypes, but no correlations survived after FDR correction.

LIMITATIONS

Our study was cross-sectional. Most of our patients were on medication, and the sample was limited.

CONCLUSIONS

Our findings demonstrated neurobiological characteristics of BD subtypes, providing evidence for BD II as an independent existence, which could be the underlying explanation for the specific symptoms and/or severity and point to potential biomarkers for the differential diagnosis of bipolar subtypes.

Characterizing the polygenic overlaps of bipolar disorder subtypes with schizophrenia and major depressive disorder

BACKGROUND

Large-scale studies have shown that bipolar I disorder (BD-I) and bipolar II disorder (BD-II) have differences in genetic association with schizophrenia (SCZ) and major depressive disorder (MDD). However, the underlying shared genetic architectures between BD subtypes and both SCZ and MDD remain largely unknown.

METHODS

We applied univariate and bivariate causal mixture models (MiXeR) to estimate the polygenicity and polygenic overlaps on large GWASs summary statistics of BD-I (n = 25,060), BD-II (n = 6781), SCZ (n = 69,369) and MDD (n = 170,756). Then, conjunctional false discovery rate approach was used to identify specific shared genetic loci between BD subtypes and both SCZ and MDD.

RESULTS

Univariate MiXeR revealed that BD-II was substantially more polygenic (22.37 K causal variants) as compared to BD-I, SCZ and MDD (7.87-12.43 K causal variants). Bivariate MiXeR revealed substantial polygenic overlaps between BD-I and SCZ (Dice-coefficient = 0.83) and between BD-I and MDD (Dice-coefficient = 0.76), which are beyond the genetic correlation (rg = 0.71 and 0.36). Conjunctional FDR analysis identified 236 distinct shared loci between BD-I and BD-II (2 loci), BD-I and SCZ (227 loci), BD-I and MDD (19 loci), BD-II and SCZ (1 locus), and BD-II and MDD (3 loci). Most of these shared loci have concordant effect directions among BD subtypes, SCZ and MDD.

LIMITATIONS

The bivariate MiXeR model was not applied for the BD-II because of insufficient power and inadequate model fit.

CONCLUSIONS

These findings provide evidence for extensive polygenic effects across BD subtypes, SCZ and MDD, which further our understanding of the potential genetic basis for the comorbid symptoms across these disorders.

Direct medical cost of bipolar disorder: Insights from the FACE-BD longitudinal cohort

BACKGROUND

Bipolar disorder (BD) is a severe chronic psychiatric disorder affecting 0.5 to 1% of the population worldwide. To date, most studies have estimated the cost of BD via information sourced from insurance claims with limited information on clinical characteristics and course of BD. The aims of this study are (i) to estimate the direct healthcare cost associated with BD and to identify contributing factors and (ii) to study the evolution of cost during a two-year follow-up period.

METHOD

We analyzed a sample of 1116 individuals with BD included in the Advanced Centers of Expertise in Bipolar Disorder cohort. We estimated the direct healthcare cost per year and per patient, and we identified the clinical features of patients with BD associated with higher direct healthcare costs. In a subsample of patients followed up for two years centers of expertise for BD, we studied the evolution of direct healthcare cost.

RESULTS

The average cost of bipolar disorder was € 6910 per year and per patient. Clinical features of BD, sociodemographic characteristics, and associated addiction were associated with higher direct healthcare costs. In the subsample of patients followed-up for two years, direct healthcare cost dropped by more than 50%, strongly suggesting the beneficial effect of specialized care organization.

LIMITATION

We did not estimate indirect healthcare and intangible costs.

CONCLUSION

Our study investigates the cost of BD and its evolution in a deeply phenotyped longitudinal sample. Cost-utility and cost-effectiveness analyses are required to inform resource allocation decisions and to promote innovative healthcare organizations.

Pilot Testing in the Wild: Feasibility, Acceptability, Usage Patterns, and Efficacy of an Integrated Web and Smartphone Platform for Bipolar II Disorder

Background

Bipolar II disorder (BD-II) is associated with significant burden, disability, and mortality; however, there continues to be a dearth of evidence-based psychological interventions for this condition. Technology-mediated interventions incorporating self-management have untapped potential to help meet this need as an adjunct to usual clinical care.

Objective

The objective of this pilot study is to assess the feasibility, acceptability, and clinical utility of a novel intervention for BD-II (Tailored Recovery-oriented Intervention for Bipolar II Experiences; TRIBE), in which mindfulness-based psychological content is delivered via an integrated web and smartphone platform. The focus of the study is evaluation of the dynamic use patterns emerging from ecological momentary assessment and intervention to assist the real-world application of mindfulness skills learned from web-delivered modules.

Methods

An open trial design using pretest and posttest assessments with nested qualitative evaluation was used. Individuals (aged 18-65 years) with a diagnosis of BD-II were recruited worldwide and invited to use a prototype of the TRIBE intervention over a 3-week period. Data were collected via web-based questionnaires and phone interviews at baseline and 3-week follow-up.

Results

A total of 25 participants completed baseline and follow-up assessments. Adherence rates (daily app use) were 65.6% across the 3-week study, with up to 88% (22/25) of participants using the app synergistically alongside the web-based program. Despite technical challenges with the prototype intervention (from user, hardware, and software standpoints), acceptability was adequate, and most participants rated the intervention positively in terms of concept (companion app with website: 19/25, 76%), content (19/25, 76%), and credibility and utility in supporting their management of bipolar disorder (17/25, 68%). Evaluation using behavioral archetypes identified important use pathways and a provisional model to inform platform refinement. As hypothesized, depression scores significantly decreased after the intervention (Montgomery-Asberg Depression Rating Scale baseline mean 8.60, SD 6.86, vs follow-up mean 6.16, SD 5.11; t₂₄=2.63; P=.01; Cohen d=0.53, 95% CI 0.52-4.36).

Conclusions

Our findings suggest that TRIBE is feasible and represents an appropriate and acceptable self-management program for patients with BD-II. Preliminary efficacy results are promising and support full development of TRIBE informed by the present behavioral archetype analysis. Modifications suggested by the pilot study include increasing the duration of the intervention and increasing technical support.

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.

Differences in prescription patterns between real-world outpatients with bipolar I and II disorders in the MUSUBI survey

OBJECTIVE

There is limited information available on the prescription of psychotropic agents to patients with bipolar I (BD-I) and bipolar II disorder (BD-II). The purpose of this study was to investigate the characteristics of drug therapy in BD-I and BD-II outpatients, particularly with regard to antidepressants.

METHODS

In 2017, the MUlticenter treatment SUrvey for BIpolar disorder in Japanese psychiatric clinics (MUSUBI) study collected data on current mental status, medications, and other factors from 2774 outpatients with BD-I or BD-II.

RESULTS

There were significant differences in the rates of prescriptions for mood stabilizers, antipsychotics and antidepressants. Mood stabilizers and antipsychotics were prescribed at higher rates to patients with BD-I (mood stabilizers; BD-I 86.0%, BD-II 80.8%, p < 0.001; antipsychotics; BD-I 61.5%, BD-II 47.8%, p < 0.001), and antidepressants were prescribed at higher rates to patients with BD-II (BD-I 32.1%, BD-II 46.4%, p < 0.001). The most commonly prescribed antidepressants were escitalopram for patients with BD-I and duloxetine for patients with BD-II. Selective serotonin reuptake inhibitors (SSRIs) were the most common class of antidepressants prescribed to patients with BD. With regard to combination therapy, combinations containing antidepressants were often prescribed to patients with BD-II.

CONCLUSION

There was a difference in the prescription of psychotropic agents between patients with BD-I and BD-II. The outpatient prescriptions for BD in Japan were mood stabilizers and antipsychotics, which generally followed the guidelines. There is insufficient evidence regarding the effects of the prescribed antidepressants and the risk of manic episodes, and further evidence needs to be collected.

Comparison of Patterns of Non-suicidal Self-Injury and Emotion Dysregulation Across Mood Disorder Subtypes

INTRODUCTION

Non-suicidal self-injury (NSSI) is frequently encountered in patients with mood disorders. Emotion dysregulation (ED), frequently observed in mood disorders, could be a major mediating factor in NSSI. The aim of this study was to explore differences in NSSI behavior and ED across mood disorder subtypes. The relationships between childhood trauma and NSSI and ED were also explored.

METHODS

A total of 191 patients with mood disorders were included in this study. The patterns of NSSI behavior and ED across patients with bipolar I disorder (BD-I), bipolar II disorder (BD-II), and major depressive disorder (MDD) were compared.

RESULTS

More than half (54%) of the subjects experienced NSSI. Patients with BD-II and MDD engaged in NSSI behavior more frequently than those diagnosed with BD-I. NSSI behaviors in patients with BD-II most commonly included cutting, whereas hitting behaviors were most common among other groups. Patients with BD-II and MDD reported more severe ED than those with BD-I. In the case of childhood trauma, those with BD-II and MDD reported greater emotional neglect than those with BD-I. Structural equation modeling revealed that ED mediated the association between childhood trauma and NSSI.

CONCLUSION

BD-I was associated with less frequent NSSI behavior and less severe ED than BD-II and MDD. ED mediated the association between childhood trauma and NSSI. Promoting emotion regulation strategies could prevent NSSI behavior in patients with mood disorders.

Symptoms and Characteristics of Youth Hospitalized for Depression: Subthreshold Manic Symptoms Can Help Differentiate Bipolar from Unipolar Depression

Background: Most people who have major depressive disorder (MDD) or bipolar disorder (BD) will have their first episode of depression in adolescence. However, in the absence of significant [hypo]manic symptoms, there are no clear guidelines for distinguishing bipolar from unipolar depression, which can lead to misdiagnosis and ineffective/harmful treatment. We aimed to compare phenomenological differences among youth with MDD or BD hospitalized for an acute episode of depression. Methods: A retrospective electronic chart review of adolescents hospitalized in an acute care inpatient unit who had a discharge diagnosis of MDD, MDD with mixed or psychotic features (MDD+), BD-I-current episode depressed, or BD-II-current episode depressed, was performed. Results: Altogether, 598 patients (mean age = 15.1 ± 1.5 years, female = 71%, and White = 46%) met study inclusion criteria, i.e., BD-I: n = 39, BD-II: n = 84, MDD: n = 422, and MDD+: n = 53 patients. The admission Hamilton Depression Rating Scale (HAMD) total score was significantly higher in the BD-I (29.3 ± 9.1) and MDD+ (31.2 ± 9.3) groups versus the MDD group (24.3 ± 9.7) (p < 0.05). Although there were some group differences in the severity of individual depression symptoms, these did not line up neatly across BD and MDD groups. At admission, Young Mania Rating Scale (YMRS) total scores were significantly higher in the BD-I (14.4 ± 7.4), BD-II (13.8 ± 6.5), and MDD+ groups (14.3 ± 6.6) versus the MDD group (8.2 ± 4.6, p < 0.05). Additionally, 9 of 11 and 4 of 11 YMRS items scored significantly higher in the BD-II and BD-I groups versus the MDD group, respectively. The motor activity and hypersexuality items, in particular, were scored consistently higher in the BD groups than MDD groups. Limitations: All diagnoses were made based on a clinical interview and not a structured diagnostic interview, and some of the subgroup sample sizes were relatively modest, limiting the power for group comparisons. Conclusion: The presence of subsyndromal manic symptoms during an episode of MDD currently offers the clearest way by which to differentiate bipolar depression from unipolar depression.

The prevalence, odds and predictors of lifespan comorbid eating disorder among people with a primary diagnosis of bipolar disorders, and vice-versa: Systematic review and meta-analysis

BACKGROUND

There are scarce and discrepant data about the prevalence and correlates of co-occurring eating disorders (EDs) among people with a primary diagnosis of bipolar disorder (BD), and vice-versa, compelling a systematic review and meta-analysis on the matter.

METHODS

MEDLINE/PsycINFO databases were systematically searched for original studies documenting BD⇌ED comorbidity across the lifespan, from inception up until April 20^th, 2020. Random-effects meta-analysis and meta-regression analyses were conducted, accounting for multiple moderators.

RESULTS

Thirty-six studies involved 15,084 primary BD patients. Eleven studies encompassed 15,146 people with primary EDs. Binge eating disorder (BED) occurred in 12.5% (95%C.I.=9.4-16.6%, I²=93.48%) of BDs, while 9.1% (95%C.I.=3.3-22.6%) of BEDs endorsed BD. Bulimia Nervosa (BN) occurred in 7.4% (95%C.I.=6-10%) of people with BD, whereas 6.7% (95%C.I.=12-29.2%) of subjects with BN had a diagnosis of BD. Anorexia Nervosa (AN) occurred in 3.8% (95%C.I.=2-6%) of people with BDs; 2% (95%C.I.=1-2%) of BD patients had a diagnosis of AN. Overall, BD patients with EDs had higher odds of being female vs. non-ED controls. Several moderators yielded statistically significant differences both within- and between different types of BDs and EDs.

LIMITATIONS

Scant longitudinal studies, especially across different EDs and pediatric samples. High heterogeneity despite subgroup comparisons. Limited discrimination of the quality of the evidence.

CONCLUSIONS

The rates of BD⇌ED comorbidity vary across different diagnostic groups, more than they do according to the "direction" of BD⇌ED. Further primary studies should focus on the risks, chronology, clinical impact, and management of the onset of intertwined BD⇌ED across different ages, promoting a continuum approach.

Clinical and genetic differences between bipolar disorder type 1 and 2 in multiplex families

The two major subtypes of bipolar disorder (BD), BD-I and BD-II, are distinguished based on the presence of manic or hypomanic episodes. Historically, BD-II was perceived as a less severe form of BD-I. Recent research has challenged this concept of a severity continuum. Studies in large samples of unrelated patients have described clinical and genetic differences between the subtypes. Besides an increased schizophrenia polygenic risk load in BD-I, these studies also observed an increased depression risk load in BD-II patients. The present study assessed whether such clinical and genetic differences are also found in BD patients from multiplex families, which exhibit reduced genetic and environmental heterogeneity. Comparing 252 BD-I and 75 BD-II patients from the Andalusian Bipolar Family (ABiF) study, the clinical course, symptoms during depressive and manic episodes, and psychiatric comorbidities were analyzed. Furthermore, polygenic risk scores (PRS) for BD, schizophrenia, and depression were assessed. BD-I patients not only suffered from more severe symptoms during manic episodes but also more frequently showed incapacity during depressive episodes. A higher BD PRS was significantly associated with suicidal ideation. Moreover, BD-I cases exhibited lower depression PRS. In line with a severity continuum from BD-II to BD-I, our results link BD-I to a more pronounced clinical presentation in both mania and depression and indicate that the polygenic risk load of BD predisposes to more severe disorder characteristics. Nevertheless, our results suggest that the genetic risk burden for depression also shapes disorder presentation and increases the likelihood of BD-II subtype development.

Does guideline-concordant care predict naturalistic outcomes in youth with early stage bipolar I disorder?

BACKGROUND

The impact of guideline concordance on naturalistic maintenance treatment outcomes in BD is not known. We sought to evaluate the effect of guideline-concordant care on symptomatic, course and functional outcomes in youth with early-stage BD-I.

METHODS

In this file audit study, we examined the prospective course of 64 clients with first treatment seeking manic episode of BD-I. Eighteen-month outcome measures included Clinical Global Impressions Scale - Bipolar Version (CGI-BP), Social and Occupational Functioning Assessment Scale (SOFAS) and number of relapses. Correlations and hierarchical linear regressions were used to examine the relationships between guideline concordance and outcomes, while controlling for potential confounders.

RESULTS

Although higher guideline-concordant care in the maintenance phase was associated with a higher discharge CGI-BP score and thus worse outcome, baseline CGI-BP and insight were more predictive of illness severity at follow-up than guideline concordance. There was no association with SOFAS and guideline-concordant care at follow-up. Greater concordance with maintenance medication guideline statements was also associated with greater number of relapses even after controlling for sex, medication adherence, duration of care and baseline illness severity.

LIMITATIONS

This study was limited by sample size and its single pool of clients which may limit generalizability.

CONCLUSIONS

Contrary to our hypotheses, higher guideline concordance was associated with worse outcomes, although this relationship was moderated by the client's illness characteristics, severity and insight. More unwell youth with poor insight, greater severity, and mixed/rapid cycling features may need other interventions or modified guidelines.

Defining phenotypes of long-term lithium and valproate response, including combination therapy: a modified application of the Alda scale in patients with bipolar disorders

BACKGROUND

When evaluating the long-term treatment response to mood stabilizers using the Alda scale, mood stabilizer combination therapy is typically considered a confounding factor, and patients receiving combination therapy are excluded from the analysis. However, this may result in bias if those under combination therapy are worse treatment responders. This study aims to explore whether the Alda scale is applicable to patients taking lithium and valproate combination therapy. We compared long-term treatment response in patients receiving monotherapy and combination therapy of the two drugs, and investigated clinical correlates of the responses to each drug.

METHODS

The study subjects consisted of 102 patients with bipolar I (BD-I) or bipolar II (BD-II) disorder who had been undergoing maintenance treatment with lithium and/or valproate for more than 2 years at a single specialized bipolar disorder clinic. Long-term treatment response was measured using the Alda scale and compared among the lithium monotherapy group, the valproate monotherapy group, and the mood stabilizer combination group. Clinical correlates of long-term treatment response were evaluated in lithium users and valproate users separately.

RESULTS

There were no significant differences in terms of baseline illness characteristics among groups. The combination group showed the worst treatment response for all the response measurements applied. This group also had the higher rate of 'poor responder' with a statistically significant difference compared to valproate group. Older age at onset and (hypo)manic episode at onset showed significant positive associations with total Alda score in lithium users, while comorbid anxiety disorders, obsessive-compulsive disorder and mixed episode showed significant negative associations in valproate users.

CONCLUSIONS

The combination group had poorer long-term treatment response but did not show distinct clinical characteristics compared to the monotherapy groups. When exploring the long-term effects of mood stabilizers, excluding patients undergoing combination treatment could result in bias because they may represent a poor response group. The long-term treatment responses of lithium and valproate had different clinical correlates.

Characteristics of bipolar I and II disorder: A study of 8766 individuals

OBJECTIVES

Large-scale studies on phenotypic differences between bipolar disorder type I (BDI) and type II (BDII) are scarce.

METHODS

Individuals with BDI (N = 4806) and BDII (N = 3960) were compared with respect to clinical features, illness course, comorbid conditions, suicidality, and socioeconomic factors using data from the Swedish national quality assurance register for bipolar disorders (BipoläR).

RESULTS

BDII had higher rate of depressive episodes and more frequent suicide attempts than BDI. Furthermore, the BDII group were younger at first sign of mental illness and showed higher prevalence of psychiatric comorbidity but were more likely to have completed higher education and to be self-sustaining than the BDI group. BDII more frequently received psychotherapy, antidepressants, and lamotrigine. BDI patients had higher rate of hospitalizations and elated episodes, higher BMI, and higher rate of endocrine, nutritional, and metabolic diseases. BDI were more likely to receive mood stabilizers, antipsychotic drugs, electroconvulsive therapy, and psychoeducation.

CONCLUSIONS

These results demonstrate clear differences between BDI and II and counter the notion that BDII is a milder form of BDI, but rather a more complex condition with regard to clinical course and comorbidity.

Symptom continuum reported by affective disorder patients through a structure-validated questionnaire

BACKGROUND

Affective disorders, such as major depressive (MDD), bipolar I (BD I) and II (BD II) disorders, are overlapped at a continuum, but their exact loci are not clear. The self-reports from patients with affective disorders might help to clarify this issue.

METHODS

We invited 738 healthy volunteers, 207 individuals with BD I, 265 BD II, and 192 MDD to answer a 79 item-MATRIX about on-going affective states.

RESULTS

In study 1, all 1402 participants were divided random-evenly and gender-balanced into two subsamples; one subsample was used for exploratory factor analysis, and another for confirmatory factor analysis. A structure-validated inventory with six domains of Overactivation, Psychomotor Acceleration, Distraction/ Impulsivity, Hopelessness, Retardation, and Suicide Tendency, was developed. In study 2, among the four groups, MDD scored the highest on Retardation, Hopelessness and Suicide Tendency, whereas BD I on Distraction/ Impulsivity and Overactivation.

CONCLUSION

Our patients confirmed the affective continuum from Suicide Tendency to Overactivation, and described the different loci of MDD, BD I and BD II on this continuum.

Comparison of Genetic Liability for Sleep Traits Among Individuals With Bipolar Disorder I or II and Control Participants

IMPORTANCE

Insomnia, hypersomnia, and an evening chronotype are common in individuals with bipolar disorder (BD), but whether this reflects shared genetic liability is unclear. Stratifying by BD subtypes could elucidate this association and inform sleep and BD research.

OBJECTIVE

To assess whether polygenic risk scores (PRSs) for sleep traits are associated with BD subtypes I and II.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study was conducted in the United Kingdom and Sweden with participants with BD and control participants. Multinomial regression was used to assess whether PRSs for insomnia, daytime sleepiness, sleep duration, and chronotype are associated with BD subtypes compared with control participants. Affected individuals were recruited from the Bipolar Disorder Research Network. Control participants were recruited from the 1958 British Birth Cohort and the UK Blood Service. Analyses were repeated in an independent Swedish sample from August 2018 to July 2019. All participants were of European ancestry.

EXPOSURES

Standardized PRSs derived using alleles from genome-wide association studies of insomnia, sleep duration, daytime sleepiness, and chronotype. These were adjusted for the first 10 population principal components, genotyping platforms, and sex.

MAIN OUTCOMES AND MEASURES

Association of PRSs with BD subtypes, determined by semistructured psychiatric interview and case notes.

RESULTS

The main analysis included 4672 participants with BD (3132 female participants [67.0%]; 3404 with BD-I [72.9%]) and 5714 control participants (2812 female participants [49.2%]). Insomnia PRS was associated with increased risk of BD-II (relative risk [RR], 1.14 [95% CI, 1.07-1.21]; P = 8.26 × 10-5) but not BD-I (RR, 0.98 [95% CI, 0.94-1.03]; P = .409) relative to control participants. Sleep-duration PRS was associated with BD-I (RR, 1.10 [95% CI, 1.06-1.15]; P = 1.13 × 10-5) but not BD-II (RR, 0.99 [95% CI, 0.93-1.06]; P = .818). Associations between (1) insomnia PRS and BD-II and (2) sleep-duration PRS and BD-I were replicated in the Swedish sample of 4366 individuals with BD (2697 female participants [61.8%]; 2627 with BD-I [60.2%]) and 6091 control participants (3767 female participants [61.8%]). Chronotype and daytime-sleepiness PRS were not associated with BD subtypes.

CONCLUSIONS AND RELEVANCE

Per this analysis, BD subtypes differ in genetic liability to insomnia and hypersomnia, providing further evidence that the distinction between BD-I and BD-II has genetic validity. This distinction will be crucial in selecting participants for future research on the role of sleep disturbance in BD.

Role of biological rhythm dysfunction in the development and management of bipolar disorders: a review

Disturbance of biological rhythms contributes to the onset of bipolar disorders and is an important clinical feature of the condition. To further explore the role of biological rhythms in bipolar disorders, 95 English articles published between 1968 and 2019 were retrieved from the PubMed database and analysed. We herein review the outcomes of studies on biological rhythm disturbance in bipolar disorders, including the epidemiology, aetiology, clinical features (eg, sleep, feeding and eating disorders) and treatment of the condition evaluated by patients’ self-report and biological indicators such as melatonin. Our report supports the characterisation of biological rhythm disturbance as a significant clinical feature affecting the onset and development of bipolar disorders and reviews classical and novel treatments, such as chronotherapy, that can be applied in the clinical practice. Our analysis indicates that a more comprehensive study of the pathophysiology, clinical phenomenology and treatment of biological rhythm disturbance is required.

Reward sensitivity and the course of bipolar disorder: A survival analysis in a treatment seeking sample

OBJECTIVES

Reward sensitivity is suggested to be an influence on the onset and reoccurrence of bipolar disorder (BD) in observational longitudinal studies. The current study examined whether reward sensitivity predicted the recurrence of mood episodes in a treatment seeking sample. We also explored if reward sensitivity moderated treatment outcomes of psychosocial treatment.

METHODS

Seventy-six euthymic adult patients with BD were randomly assigned to either Cognitive Behavioral Therapy (CBT) or Supportive Therapy (ST) and followed up for 2 years after completing therapy (Meyer and Hautzinger, 2012). The primary outcome measure was recurrence of mood episodes. The final multivariate Cox regression models included potential covariates, therapy conditions, BAS reward sensitivity, and the interaction between BAS and therapy conditions.

RESULTS

BAS emerged as the only significant predictor of time till recurrence of mania, but not depression, but the overall model did not reach significance. There was no interaction between treatment and BAS reward sensitivity. Interestingly, a diagnosis of BD II predicted time till recurrence of depression.

CONCLUSION

The main result regarding BAS partially confirms prior studies linking BAS and mania, but power and the specific sample seeking psychosocial treatment might have reduced the effect.

The comorbidity of eating disorders in bipolar disorder and associated clinical correlates characterised by emotion dysregulation and impulsivity: A systematic review

BACKGROUND

Individuals with bipolar disorder (BD) have an increased risk of developing eating disorders (ED) or disordered eating symptoms compared to the general population. Eating pathology characterised by binge and/or purge symptomatology are the most common to develop in BD, yet the underlying aetiological mechanisms are relatively unknown. Theoretical models of BD-ED comorbidity suggest that shared pathophysiological factors, including emotion dysregulation and impulsivity may contribute to the development of binge/purge eating pathology in BD.

METHOD

A systematic search was conducted to assess two research questions: 1. What are the prevalence or incidence rates of different ED in BD? 2. Are clinical correlates hallmarked by emotion dysregulation and/or impulsivity (alcohol/substance use disorders, mood instability and suicidality) significantly elevated in BD with ED (BD-ED) groups compared to BD only?

RESULTS

Any type of lifetime or current ED ranged from 1.9% to 33.3% in BD. Type of BD diagnosis did not appear to significantly impact likelihood of ED development. Alcohol use disorder, mood instability and suicidality were significantly higher in BD-ED compared to BD only.

LIMITATIONS

Potential biases within the selected studies; impacting generalisability of results and comparability between studies. Varying treatment interventions (including medications) may confound results and comparability between studies. Assessment of binge eating varied, also limiting comparability.

CONCLUSION

Eating pathology may occur comorbidly with BD due to shared underlying pathophysiological features. This could have significant implications for future interventions; both psychopharmacological and psychotherapeutic. More comprehensive investigations are required to identify the functionality of dysregulated emotion and impulsivity in the development of eating pathology in BD.

Bipolar subtypes and their clinical correlates in a sample of 391 bipolar individuals

Differences between BD-I and BD-II patients with regard to specific illness characteristics are poorly understood. This study is mainly aimed to compare socio-demographic and clinical characteristics between BD-I and BD-II patients with the goal of clarifying possible predictors of clinical course. The sample of this cohort study is composed of 391 currently euthymic bipolar patients. Participants were all receiving only maintenance treatment; their psychopharmacological regimens and psychopathological conditions were stable at assessment. After univariate analyses, BD-II patients were more likely to be female, had more frequently a recent depressive episode and substance abuse/dependence relative to BD-I subjects. BD-II patients were also less likely to have a positive history of psychiatric conditions in family, psychotic symptoms at first episode, and first depressive illness episode. Moreover, BD-II were older at their illness onset and first treatment than BD-I patients. Furthermore, BD-I were more likely to have higher depressive, manic, anxiety, and symptoms severity than BD-II patients. After logistic regression analyses, being female (OR = 0.289), having psychiatric conditions in family (OR = 0.273), and higher severity of illness at CGI (OR = 0.604) were all significantly associated with BD-II. Additional studies are required to replicate these results, and facilitate the prediction of BD outcomes according to the specified profile.

Psychopathologic structure of bipolar disorders: exploring dimensional phenotypes, their relationships, and their associations with bipolar I and II disorders

BACKGROUND

Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.

METHODS

We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.

RESULTS

We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.

CONCLUSIONS

We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.

Amygdala Resting State Connectivity Differences between Bipolar II and Borderline Personality Disorders

BACKGROUND

Borderline personality disorder (BPD) and bipolar II disorder (BD II) have significant clinical overlap, leaving the potential for diagnostic inaccuracies and inadequate treatment recommendations. However, few studies have probed for clinical and neurobiological differences between the two disorders. Clinically, some prior studies have linked BPD with greater impulsivity and more frequent negative affective shifts than BD II, whereas previous neuroimaging studies have highlighted both similar and distinct neural abnormalities in BPD and BD II. Notably, no prior study has specifically targeted cortico-limbic neural differences, which have been hypothesized to underlie these core clinical differences.

METHODS

Individuals with BPD (n = 14) and BD II (n = 15) completed various clinical measures and a resting state functional imaging scan at 3T. Whole-brain amygdala resting state functional connectivity (RSFC) was compared between the two groups.

RESULTS

Relative to the BD II group, BPD participants reported significantly higher levels of impulsivity, trait anxiety, more frequent negative affective shifts, greater interpersonally reactive affective instability, lower overall functioning, and were characterized by lower amygdala-middle frontal gyrus RSFC. Lower amygdala-middle frontal gyrus RSFC was associated with greater impulsivity, trait anxiety, affective shifts, interpersonal affective reactivity, and functional impairment.

LIMITATIONS

The current study consisted of small sample sizes and lacked a control group.

CONCLUSIONS

This preliminary study suggests that amygdala-frontal RSFC may distinguish BPD from BD II. These results may guide future work aimed at identifying neural markers that can help disentangle these two disorders, leading to greater diagnostic accuracy and appropriate treatment implementation.

Hypochondriac concerns and correlates of personality styles and affective states in bipolar I and II disorders

BACKGROUND

Hypochondriac concerns are associated with the treatment-difficulty of bipolar disorder, which might be due to the personality styles and affective states.

METHODS

We invited outpatients with bipolar I disorder (BD I, n = 87), bipolar II disorder (BD II, n = 92) and healthy volunteers (n = 129) to undergo the Illness Attitude Scales and Parker Personality Measure tests, and measurements of concurrent affective states.

RESULTS

Compared to healthy volunteers, BD I and BD II patients scored significantly higher on mania, hypomania and depression. BD I and BD II patients also scored significantly higher on Symptom Effect and Treatment Seeking, and BD II patients scored higher on Patho-thanatophobia and Hypochondriacal Belief. BD II in addition scored higher on Patho-thanatophobia than BD I did. In controls, the Dependent style predicted Patho-thanatophobia and Symptom Effect, Schizoid with Hypochondriacal Belief; in BD I, Narcissistic (-) with Hypochondriacal Belief, Histrionic with Patho-thanatophobia and Hypochondriacal Belief, depression with Hypochondriacal Belief, and hypomania with Symptom Effect and Hypochondriacal Belief; in BD II, depression with Symptom Effect and Hypochondriacal Belief, mania with Symptom Effect.

CONCLUSIONS

Bipolar disorder, especially BD II, is associated with greater hypochondriac concerns, which relates to personality disorder functioning styles and concurrent affective states.

Differences in Psychopathology between Offspring of Parents with Bipolar I Disorder and Those with Bipolar II Disorder: A Cross-Sectional Study

OBJECTIVE

The aim of this study was to evaluate differences in psychopathology between offspring of parents with bipolar I disorder (BP-I) and those with bipolar II disorder (BP-II).

METHODS

The sample included 201 offspring between 6 and 17 years of age who had at least one parent with BP-I or BP-II. The offspring were diagnostically evaluated using the Korean Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. Psychopathology and Clinical characteristics were evaluated, including lifetime DSM-5 diagnoses, depression, and childhood trauma. Lifetime DSM-5 diagnoses were also compared between schoolchildren aged 6 to 11 years and adolescents aged 12 to 17 years.

RESULTS

In lifetime DSM-5 diagnoses, offspring of parents with BP-I had significantly increased risk of developing MDD and BP-I than those with BP-II. Regarding clinical characteristics, ADHD rating scale and childhood trauma scale were significantly higher in offspring of parents with BP-I than that in those with BP-II.

CONCLUSION

The present study supports that BP-I may be etiologically distinct from BP-II by a possible genetic liability. Our findings indicate that additional research related to bipolar offspring is needed to enhance understanding of differences between BP-I and BP-II.

Depressive residual symptoms are associated with illness course characteristics in a sample of outpatients with bipolar disorder

Rates of 50-70% of residual symptoms referring to subsyndromal manifestations between episodes that do not meet the required criteria for episode definition were reported in bipolar disorder (BD). However, the specific role of these symptoms on the course of BD patients is poorly understood; thus, we aimed to investigate factors associated with depressive residual symptoms. Overall, 255 currently euthymic BD outpatients on maintenance treatment, including 95 (37.2%) males and 160 (62.8%) females, were consecutively recruited at the Section of Psychiatry, Department of Neuroscience, University of Genoa (Italy) and underwent detailed structured interviews, comprehensive clinical interviews, and clinical record reviews for assessment/collection of relevant information concerning the course of illness and clinical status including cross-referral of all available information. After categorizing subjects according to the presence/absence of residual symptoms, groups were compared along clinical variables and variables associated with residual symptoms were analyzed using multivariate analyses. Subjects with residual symptoms were less likely to report substance abuse (χ²₍₂₎ = 11.937, p ≤ 0.005) and lifetime psychotic symptoms (χ²₍₂₎ = 10.577, p = 0.005), and more likely to report higher illness episodes, longer duration of illness (t₂₅₃ = 67.282, p ≤ 0.001; t₂₅₃ = 10.755, p ≤ 0.001), and longer duration of current illness episode (t₂₅₃ = 7.707, p ≤ 0.001) than those without residual symptoms. After multivariate analyses, a significant positive contribution to residual symptoms was given only by duration of current illness episode (β = 0.003; p ≤ 0.05), and lifetime psychotic symptoms (β = 1.094; p ≤ 0.005). Clinicians have to pay attention to minimize residual symptoms that may significantly impact on the course of BD and achievement of full remission between episodes.

Clinical characteristics of patients with bipolar disorder and premorbid traumatic brain injury: a cross-sectional study

BACKGROUND

About one in ten diagnosed with bipolar disorder (BD) has experienced a premorbid traumatic brain injury (TBI), while not fulfilling the criteria of bipolar and related disorder due to another medical condition (BD due to TBI). We investigated whether these patients have similar clinical characteristics as previously described in BD due to TBI (i.e. more aggression and irritability and an increased hypomania/mania:depression ratio) and other distinct clinical characteristics.

METHODS

Five hundred five patients diagnosed with BD type I, type II, or not otherwise specified, or cyclothymia were interviewed about family, medical, and psychiatric history, and assessed with the Young Mania Rating Scale (YMRS) and the Inventory of Depressive Symptoms Clinician Rated 30 (IDS-C₃₀). Principal component analyses of YMRS and IDS-C₃₀ were conducted. Bivariate analyses and logistic regression analyses were used to compare clinical characteristics between patients with (n = 37) and without (n = 468) premorbid TBI.

RESULTS

Premorbid TBI was associated with a higher YMRS disruptive component score (OR 1.7, 95% CI 1.1-2.4, p = 0.0077) and more comorbid migraine (OR 4.6, 95% CI 1.9-11, p = 0.00090) independently of several possible confounders. Items on disruptive/aggressive behaviour and irritability had the highest loadings on the YMRS disruptive component. Premorbid TBI was not associated with an increased hypomania/mania:depression ratio.

CONCLUSIONS

Disruptive symptoms and comorbid migraine characterize BD with premorbid TBI. Further studies should examine whether the partial phenomenological overlap with BD due to TBI could be explained by a continuum of pathophysiological effects of TBI across the diagnostic dichotomy. Trial registration ClinicalTrials.gov: NCT00201526. Registered September 2005 (retrospectively registered).

Fractional anisotropy of the uncinate fasciculus and cingulum in bipolar disorder type I, type II, unaffected siblings and healthy controls

BACKGROUND

Fractional anisotropy in the uncinate fasciculus and the cingulum may be biomarkers for bipolar disorder and may even be distinctly affected in different subtypes of bipolar disorder, an area in need of further research.AimsThis study aims to establish if fractional anisotropy in the uncinate fasciculus and cingulum shows differences between healthy controls, patients with bipolar disorder type I (BD-I) and type II (BD-II), and their unaffected siblings.

METHOD

Fractional anisotropy measures from the uncinate fasciculus, cingulum body and parahippocampal cingulum were compared with tractography methods in 40 healthy controls, 32 patients with BD-I, 34 patients with BD-II, 17 siblings of patients with BD-I and 14 siblings of patients with BD-II.

RESULTS

The main effects were found in both the right and left uncinate fasciculus, with patients with BD-I showing significantly lower fractional anisotropy than both patients with BD-II and healthy controls. Participants with BD-II did not differ from healthy controls. Siblings showed similar effects in the left uncinate fasciculus. In a subsequent complementary analysis, we investigated the association between fractional anisotropy in the uncinate fasciculus and polygenic risk for bipolar disorder and psychosis in a large cohort (n = 570) of healthy participants. However, we found no significant association.

CONCLUSIONS

Fractional anisotropy in the uncinate fasciculus differs significantly between patients with BD-I and patients with BD-II and healthy controls. This supports the hypothesis of differences in the physiological sub-tract between bipolar disorder subtypes. Similar results were found in unaffected siblings, suggesting the potential for this biomarker to represent an endophenotype for BD-I. However, fractional anisotropy in the uncinate fasciculus seems unrelated to polygenic risk for bipolar disorder or psychosis.Declaration of interestNone.

The views of early intervention service staff on the treatment of first episode bipolar disorder

OBJECTIVE

Little is known about how first episode bipolar disorder (BD) is managed in early intervention for psychosis services (EIS). We aimed to investigate the knowledge and views of EIS staff on the assessment and treatment of BD.

METHODS

A 27-item anonymised online questionnaire was distributed to EIS mental health professionals in England. Descriptive data analysis was undertaken.

RESULTS

Responses were received from 117 EIS staff. Most were 'fairly confident' in their knowledge about causes, presentations and relapse indicators of BD, but less confident on pharmacological and psychological treatments. Eighty five percent expressed the view that more BD training was necessary in this area with 78% reporting no clear care packages within the service. Seventy two percent believe early BD should be treated within EIS only if patients have psychosis.

CONCLUSIONS

Clearer care packages and staff training are needed for EIS staff to optimise care for BD.

Design limitations to bipolar II treatment efficacy studies: A challenge and a revisionist strategy

BACKGROUND

Trials examining medication efficacy for bipolar II disorder commonly employ a set of standardized interval measures to assess outcomes. The key issue is whether such interval measures pick up changes in the severity, duration and frequency of depressive, hypomanic and euthymic episodes.

METHOD

We examine the application of measures most commonly used to monitor progress in nine studies involving participants with a bipolar II disorder and published in journals with a moderate to high impact factor.

RESULTS

Studies rarely provided interval details for assessing depressive and hypomanic symptoms. None specified whether ratings of depressive and hypomanic symptoms were based on severity, duration or number of symptoms, and none recorded any data on euthymic periods.

LIMITATIONS

Our sample of reviewed studies was small and our analyses focused only on the three most commonly used outcome measures. We advocate for complementary subjective daily mood monitoring strategies but recognize that such strategies need to be validated in future studies.

CONCLUSIONS

We argue that interval ratings undertaken weekly or over longer periods may compromise efficacy data. We recommend that userguides be developed to ensure standard outcome measures are employed consistently across trials, and that specific details be published in trial papers about how measures were employed and what mood episode characteristics were measured at each assessment. We also argue for daily ratings to be used as an outcome measure to provide data on severity, frequency and duration of depressive, hypomanic and euthymic periods in intervention studies of those with a bipolar II disorder.

Socio-demographic and clinical characterization of patients with Bipolar Disorder I vs II: a Nationwide Italian Study

Bipolar disorders (BDs) are prevalent, comorbid and disabling conditions, associated with the highest suicide risk among psychiatric illnesses. In the last few years, new efforts to better characterize the socio-demographic and clinical profiles of BD type I vs II have been documented by several reports, with novel and insightful findings in the field. The present multicenter study aimed to provide a comprehensive and reliable representation of the Italian reality, through the analysis of the largest national sample of bipolar patients collected so far. A total of 1500 patients (BD I n = 963 and BD II n = 537) from different psychiatric departments, participating in the Italian Chapter of the "International Society of Bipolar Disorders" (ISBD), were assessed and divided into two groups on the basis of their diagnostic subtype, and different socio-demographic and clinical variables were compared between the two subgroups. Chi-squared tests for categorical variables and t tests for continuous variables were performed for group comparison. Furthermore, a multivariable logistic regression was performed, considering diagnostic bipolar subtype (type I or II) as dependent variable, and socio-demographic/clinical characteristics as independent variables. BD I vs II patients showed an overall less favorable socio-demographic and clinical profile. In addition, the multivariable logistic regression showed that BD II vs BD I was predicted by the absence of lifetime suicide attempts (OR = 1.58, p = 0.01), a later age of diagnosis (OR = 1.03, p < 0.01), less hypomanic episodes in the last year (OR = 2.29, p < 0.0001) and absence of psycho-educational interventions in the last year (OR = 0.51, p < 0.01). BD I and II patients were found to significantly differ in relation to specific clinical variables, which should be considered within updated diagnostic-therapeutic algorithms.

Differentiating multiple vs single lifetime suicide attempters with bipolar disorders: A retrospective study

BACKGROUND

The risk of suicide in Bipolar Disorder (BD) has been estimated up to 20-30 times higher compared with the general population. Previous suicide attempts (SAs) represent a well-established risk factor for further attempts and for death by suicide in patients with psychiatric disorders. However, little is known about the socio-demographic and clinical profile of BD patients with a history of multiple SAs (MSAs). The present study sought to characterize BD patients with MSAs versus single suicide attempt (SSA) within a large Italian sample.

METHODS

An original sample of 354 bipolar patients, recruited at the University Clinic and related community services at the Department of Psychiatry, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico of Milan (Italy), was screened for the presence of previous SAs (n=95). Socio-demographic and clinical variables were then compared between patients with multiple vs single lifetime suicide attempts.

RESULTS

Bipolar patients with MSAs versus SSA had longer bipolar illness duration (26.9±12.6 vs 21.2±12.8years; p=0.05), and more frequently lived alone (38.5% vs 17.2%; p<0.05), had more than one psychiatric comorbidity (39.3% vs 17.5%; p=0.04), and utilized substance ingestion (e.g., overdose) (78.6% vs 47.2%, p=0.009), although the latter was the most common suicide attempt method in both groups.

CONCLUSION

Present findings suggest different socio-demographic and clinical characteristics in bipolar patients with MSAs versus SSA. Further investigation is needed to confirm reported data.

Disrupted Cerebellar Connectivity With the Central Executive Network and the Default-Mode Network in Unmedicated Bipolar II Disorder

Objective: Bipolar disorder (BD) is a common psychiatric disease. Although structural and functional abnormalities of the cerebellum in BD patients have been reported by recent neuroimaging studies, the cerebellar-cerebral functional connectivity (FC) has not yet been examined. The present study aims to investigate the FC between the cerebellum and cerebrum, particularly the central executive network (CEN) and the default-mode network (DMN) in bipolar II disorder (BD II). Methods: Ninety-four patients with unmedicated BD II depression and 100 healthy controls (HCs) underwent the resting-state functional magnetic resonance imaging. Seed-based connectivity analyses were performed using cerebellar seeds previously identified as being involved in the CEN (bilateral Crus Ia) and DMN (bilateral Crus Ib). Results: Compared with HCs, BD II depression patients appeared decreased FC in the right Crus Ia-left dorsal lateral prefrontal cortex (dlPFC) and -left anterior cingulate cortex (ACC), the right Crus Ib-left medial prefrontal cortex (mPFC), -left middle temporal gyrus (MTG), and -left inferior temporal gyrus (ITG). No altered FC between the left Crus Ia or Crus Ib and the cerebral regions was found. Conclusions: Patients with BD II depression showed disrupted FC between the cerebellum and the CEN (mainly in the left dlPFC and ACC) and DMN (mainly in the left mPFC and temporal lobe), suggesting the significant role of the cerebellum-CEN and -DMN connectivity in the pathogenesis of BD.

Blink reflex under external emotional-stimuli in bipolar I and II disorders

Bipolar disorder types I (BD I) and II (BD II) might present different cortico-brainstem circuit dysfunctions under external emotions, which might be reflected by the blink reflex. We therefore invited 32 BD I and 23 BD II patients, and 46 healthy volunteers to answer the Mood Disorder Questionnaire, the Hypomania Checklist-32, and the Plutchik - van Praag Depression inventory, and to undergo the blink reflex test under external emotions (emotional pictures plus sounds) of Disgust, Erotica, Fear, Happiness, and Sadness. Compared to healthy controls, BD I showed prolonged R2/R2' latencies under most emotions, and their PVP scores were negatively correlated with the areas under curve (AUCs) of R2 and R2' under Erotica; and BD II showed reduced R2/R2' AUCs under all emotions. Moreover, R2' AUCs under Disgust, Fear, and Happiness were significantly reduced in BD II than those in BD I. Our results have shown that, irrespective of patients' on-going affective states, the R2/R2' components were delayed in BD I but suppressed in BD II under most external emotions. Our study provides some hints to distinguish the two types of bipolar disorder, referring to the cortico-brainstem circuit dysfunctions under external emotions.

Possible predictors of age at illness onset and illness duration in a cohort study comparing younger adults and older major affective patients

BACKGROUND

Major affective conditions are associated with significant disability and psychosocial impairment. Whether specific socio-demographic and clinical characteristics may distinguish subgroups of patients in terms of prognosis and illness trajectories is a matter of debate.

METHODS

The sample of this naturalistic cohort study included 675 currently euthymic patients with major affective disorders of which 428 (63.4%) were diagnosed with unipolar and 247 (36.6%) with bipolar disorders.

RESULTS

Younger adults with a longer duration of untreated illness and residual inter-episodic symptoms were more likely to be single or divorced, students, with an earlier age of first treatment/hospitalization, longer duration of substance abuse and duration of illness than older patients who were, conversely, more likely to be widowed and retired. Multivariate analyses showed a significant positive contribution to age at illness onset by marital status, nonpsychiatric medications, substance abuse, psychiatric diagnosis (bipolar vs. unipolar), age at first treatment/hospitalization, duration of illness, and current age. According to a further analysis, we also found a significant positive contribution to duration of illness by marital status, educational level, positive history of psychiatric conditions in family, substance abuse, psychiatric diagnosis (bipolar vs. unipolar), age at illness onset, age at first treatment, and certain cardiovascular disorders.

CONCLUSIONS

There are substantial socio-demographic and clinical differences that may help to distinguish specific subgroups of patients; however, additional studies are requested to replicate these results and further investigate the main factors underlying our findings.

Long-term response to mood stabilizer treatment and its clinical correlates in patients with bipolar disorders: a retrospective observational study

BACKGROUND

The efficacy and utility of long-term prophylactic treatment in patients with bipolar disorders (BDs) have not been fully explored. This study aims to estimate the long-term clinical response of patients with BDs to mood stabilizer treatment and to identify the clinical factors associated with that response.

METHODS

The study subjects consisted of 80 patients with bipolar I or bipolar II disorder who had been receiving treatment with lithium and/or valproate for more than 2 years at a single bipolar disorder clinic. The long-term response to the best treatment option based on treatment algorithms was evaluated using the Alda scale. Clinical characteristics were evaluated on a lifetime basis. Patients were classified into two response groups based on frequentist mixture analysis using the total Alda scale score.

RESULTS

Thirty-four percent of the patients were good responders, with a total Alda score of 5 or higher. The treatment response rate did not differ between the lithium and valproate groups, but lithium and valproate combination therapy was associated with poorer response. The number of previous mixed episodes was associated with a worse response (p = 0.026). Of individual symptoms, delusions during manic episodes (p = 0.008) and increased appetite (p = 0.035) during depressive episodes were more common in moderate/poor responders than in good responders. Co-morbid anxiety disorders were more frequently observed in the moderate/poor response group (p = 0.008).

CONCLUSIONS

Psychotic, mixed, and atypical features of BDs were found to be correlated with long-term treatment outcomes. Lithium and valproate showed similar efficacy but moderate/poor responders preferred to use polypharmacy.

Sleep loss as a trigger of mood episodes in bipolar disorder: individual differences based on diagnostic subtype and gender

BackgroundSleep loss may trigger mood episodes in people with bipolar disorder but individual differences could influence vulnerability to this trigger.AimsTo determine whether bipolar subtype (bipolar disorder type I (BP-I) or II (BD-II)) and gender were associated with vulnerability to the sleep loss trigger.MethodDuring a semi-structured interview, 3140 individuals (68% women) with bipolar disorder (66% BD-I) reported whether sleep loss had triggered episodes of high or low mood. DSM-IV diagnosis of bipolar subtype was derived from case notes and interview data.ResultsSleep loss triggering episodes of high mood was associated with female gender (odds ratio (OR) = 1.43, 95% CI 1.17-1.75, P < 0.001) and BD-I subtype (OR = 2.81, 95% CI 2.26-3.50, P < 0.001). Analyses on sleep loss triggering low mood were not significant following adjustment for confounders.ConclusionsGender and bipolar subtype may increase vulnerability to high mood following sleep deprivation. This should be considered in situations where patients encounter sleep disruption, such as shift work and international travel.

Clinical correlates of age at onset distribution in bipolar disorder: a comparison between diagnostic subgroups

Background

Admixture analysis of age at onset (AAO) has helped delineating the clinical profile of early onset (EO) bipolar disorder (BD). However, there is scarce evidence comparing the distributional properties of AAO as well as the clinical features of EO BD type 1 (BD1) with EO BD type 2 (BD2). To this end, we studied 515 BD patients (224 BD1, 279 BD2, and 12 BD not otherwise specified [NOS]) diagnosed according to DSM-IV-TR criteria.

Methods

AAO was defined as the first reliably diagnosed hypo/manic or depressive episode according to diagnostic criteria. We used normal distribution mixture analysis to identify subgroups of patients according to AAO. Models were chosen according to the Schwarz’s Bayesian information criteria (BIC). Clinical correlates of EO were analysed using univariate tests and multivariate logistic regression models.

Results

A two normal components model best fitted the observed distribution of AAO in BD1 (BIC = −1599.3), BD2 (BIC = −2158.4), and in the whole sample (BIC = −3854.9). A higher number of EO BD2 patients had a depression-(hypo)mania-free interval (DMI) course, while a higher rate of (hypo)mania-depression-free interval (MDI) course was found in EO BD1. EO BD2 had also a higher rate of comorbidity with alcohol dependence compared to EO BD1. The latter finding was confirmed by multivariate logistic regression analysis.

Conclusions

In conclusion, both BD1 and BD2 had bimodal AAO distributions, but EO subgroups had a diagnostic-specific clinical delineation.

Italian Bipolar II vs I patients have better individual functioning, in spite of overall similar illness severity

Introduction Bipolar disorders (BDs) comprise different variants of chronic, comorbid, and disabling conditions, with relevant suicide and suicide attempt rates. The hypothesis that BD types I (BDI) and II (BDII) represent more and less severe forms of illness, respectively, has been increasingly questioned over recent years, justifying additional investigation to better characterize related sociodemographic and clinical profiles.

METHODS

A sample of 217 outpatients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)-described BD (141 BDI, 76 BDII), without a current syndromal mood episode, was recruited, and sociodemographic and clinical characteristics of BDI and II patients were compared.

RESULTS

BDII patients had significantly more favorable sociodemographics, in relation to occupational stability, cohabitation, and marital status. However, BDII compared with BDI patients had significantly longer duration of untreated illness, more frequent lifetime anxiety disorders comorbidity, longer most recent episode duration, higher rate of depressive first/most recent episode, and more current antidepressant use. In contrast, BDI compared with BDII patients had significantly more severe illness in terms of earlier age at onset; higher rate of elevated first/most recent episode, lifetime hospitalizations, and involuntary commitments; lower Global Assessment of Functioning score; and more current antipsychotic use. BDI and II patients had similar duration of illness, psychiatric family history, lifetime number of suicide attempts, current subthreshold symptoms, history of stressful life events, and overall psychiatric/medical comorbidity.

CONCLUSION

BDII compared with BDI patients had more favorable sociodemographic features, but a mixture of specific unfavorable illness characteristics, confirming that BDII is not just a milder form of BD and requires further investigation in the field.

Inhibitory brainstem reflexes under external emotional-stimuli in bipolar I and II disorders

BACKGROUND

Bipolar disorder types I (BD I) and II (BD II) might present different dysfunctions of the cortex and brainstem, as reflected by the second exteroceptive suppression period of temporalis muscle activity (ES2) under different stimuli of external emotions.

METHODS

This study included 30 BD I and 20 BD II patients, and 40 healthy volunteers. All participants were invited to answer the Mood Disorder Questionnaire, the Hypomania Checklist-32, and the Plutchik-van Praag Depression inventory, as well as to undergo the ES2 test under external emotional-stimuli (emotional pictures plus sounds) of Disgust, Erotica, Fear, Happiness, and Sadness.

RESULTS

The scale scores were elevated in both patient groups, but were not correlated with ES2 parameters. Compared to healthy controls, BD I showed prolonged ES2 latency under Erotica, and their perceived happiness and sadness intensities were negatively correlated with the respective ES2 durations, while BD II showed prolonged ES2 latencies under Disgust and Happiness, and shortened ES2 durations under Disgust, Happiness and Sadness. Moreover, ES2 duration under Sadness was significantly shorter in BD II than that in BD I.

CONCLUSIONS

The cortico-brainstem inhibitory dysfunctions in BD I and BD II was different, and this difference was independent of the patient's ongoing emotions. Our study thus provides some hints to distinguish the two types of bipolar disorders.