Validating a two-dimensional bipolar spectrum model integrating DSM-5's mixed features specifier for Major Depressive Disorder

A Magnetic Resonance Spectroscopy Study on Polarity Subphenotypes in Bipolar Disorder

Although magnetic resonance spectroscopy (MRS) has provided in vivo measurements of brain chemical profiles in bipolar disorder (BD), there are no data on clinically and therapeutically important onset polarity (OP) and predominant polarity (PP). We conducted a proton MRS study in BD polarity subphenotypes, focusing on emotion regulation brain regions. Forty-one euthymic BD patients stratified according to OP and PP and sixteen healthy controls (HC) were compared. 1H-MRS spectra of the anterior and posterior cingulate cortex (ACC, PCC), left and right hippocampus (LHIPPO, RHIPPO) were acquired at 3.0T to determine metabolite concentrations. We found significant main effects of OP in ACC mI, mI/tNAA, mI/tCr, mI/tCho, PCC tCho, and RHIPPO tNAA/tCho and tCho/tCr. Although PP had no significant main effects, several medium and large effect sizes emerged. Compared to HC, manic subphenotypes (i.e., manic-OP, manic-PP) showed greater differences in RHIPPO and PCC, whereas depressive suphenotypes (i.e., depressive-OP, depressive-PP) in ACC. Effect sizes were consistent between OP and PP as high intraclass correlation coefficients (ICC) were confirmed. Our findings support the utility of MRS in the study of the neurobiological underpinnings of OP and PP, highlighting that the regional specificity of metabolite changes within the emotion regulation network consistently marks both polarity subphenotypes.

Identifying predictive factors for mood recurrence in early-onset major mood disorders: A 4-year, multicenter, prospective cohort study

We investigate the predictive factors of the mood recurrence in patients with early-onset major mood disorders from a prospective observational cohort study from July 2015 to December 2019. A total of 495 patients were classified into three groups according to recurrence during the cohort observation period: recurrence group with (hypo)manic or mixed features (MMR), recurrence group with only depressive features (ODR), and no recurrence group (NR). As a result, the baseline diagnosis of bipolar disorder type 1 (BDI) and bipolar disorder type 2 (BDII), along with a familial history of BD, are strong predictors of the MMR. The discrepancies in wake-up times between weekdays and weekends, along with disrupted circadian rhythms, are identified as a notable predictor of ODR. Our findings confirm that we need to be aware of different predictors for each form of mood recurrences in patients with early-onset mood disorders. In clinical practice, we expect that information obtained from the initial assessment of patients with mood disorders, such as mood disorder type, family history of BD, regularity of wake-up time, and disruption of circadian rhythms, can help predict the risk of recurrence for each patient, allowing for early detection and timely intervention.

Predominant polarity as a neurobiological specifier in bipolar disorder: Evidence from a multimodal neuroimaging study

BACKGROUND

While predominant (PP) and onset polarity (OP) have considerable clinical and treatment implications in bipolar disorder (BD), the neurobiological underpinnings of PP and OP from a radiological perspective remain largely unknown. The main objective of this study is to investigate the neuroanatomical profile of polarity subphenotypes (PP and OP) in euthymic BD patients, using a standardized multimodal neuroimaging protocol to evaluate regional gray matter (GM) volumes, cortical thickness, as well as white matter (WM) integrity of major projection, commissural and association tracts.

METHODS

Forty-two euthymic BD patients stratified for PP and OP and 42 healthy controls (HC) were included in this computational neuroimaging study to comprehensively characterize gray and white matter alterations. Univariate analyses of covariance (ANCOVAs) were conducted with Bonferroni corrections for each MRI modality and Cohen's d effect sizes were calculated for group comparisons.

RESULTS

Phenotype-associated cortical thickness abnormalities and volumetric alterations were identified, but no WM changes ascertained. Specifically, we found a main effect of OP on GM volume of left middle frontal gyrus and of OP and PP (either or both) on cortical thickness of various regions previously implicated in BD, i.e. inferior frontal gyrus-pars opercularis (left) and pars orbitalis (bilateral), left lateral orbitofrontal gyrus, bilateral medial segment of the superior frontal gyrus, left planum polare, right anterior cingulate gyrus, left anterior and posterior insula, bilateral frontal operculum (both OP and PP); left anterior and posterior orbitofrontal gyrus, left transverse temporal gyrus, right posterior insula (only OP); and right medial frontal cortex (only PP). Based on the magnitude of differences on pairwise comparisons, we found a large effect of OP on cortical thickness in a single region (left anterior orbitofrontal gyrus) (OP-M > OP-D), while PP subgroups showed large or medium effect size differences in cortical thickness (PP-M > PP-D) in a wider array of regions (right medial frontal cortex, left frontal operculum, left inferior frontal gyrus-pars opercularis, bilateral medial segment of the superior frontal gyrus). For most regions, PP-D patients showed the greatest decreases in cortical thickness compared to HC while PP-M showed the smallest, with PP-U showing an "unspecified" pattern mostly lying in-between PP-D and PP-M.

CONCLUSIONS

Our multimodal imaging findings suggest specific polarity BD subgroups with compromised cortical thickness; we recorded a greater impact of PP on brain structure compared to OP, which provides additional evidence that PP can be considered as a neurobiological specifier in BD.

Sex differences in maturation and aging of human personality on the basis of a recently developed complex hierarchical model of temperament and character

OBJECTIVE

The current study aimed to determine the changes in psychological function that come with age. The basis to assess psychological function was a hierarchical model of temperament, personality and character, previously developed by the authors.

METHODS

734 general population subjects completed the TEMPS-A, the TCI and the NEO-PI-3. Data were analysed with ANCOVA models.

RESULTS

The top superfactors showed no age change, however, age-related changes were identified in the higher and lower modules. There was a pattern of differences between the two genders in all levels of the model.

CONCLUSIONS

While there is stability with the two top factors of personality, there are age-related changes in lower-level modules probably indicating maturation, adaptation or changes in orientation through the adult life span. Gender differences in all levels including the two top superfactors, higher and lower modules reflect and explain differences in multiple aspects of internal experience, interaction and behaviour in the two genders. The results are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management.Key PointsBased on the complex hierarchical temperament model four stages of maturation of human psychological function can be postulated.There is a very specific trait core of human mental function, which differs between genders and seems to be responsible for the longitudinal stability of the person's internal experience with the passing of the years.The findings are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management.

Cerebro-cerebellar white matter connectivity in bipolar disorder and associated polarity subphenotypes

BACKGROUND

The cerebellum has a crucial role in mood regulation. While cerebellar grey matter (GM) alterations have been previously reported in bipolar disorder (BD), cerebro-cerebellar white matter (WM) connectivity alterations and cerebellar GM profiles have not been characterised in the context of predominant polarity (PP) and onset polarity (OP) subphenotypes of BD patients which is the aim of the present study.

METHODS

Forty-two euthymic BD patients stratified for PP and OP and 42 healthy controls (HC) were included in this quantitative neuroimaging study to evaluate cerebellar GM patterns and cerebro-cerebellar WM connections. Diffusion tensor tractography was used to characterise afferent and efferent cerebro-cerebellar tract integrity. False discovery rate corrections were applied in post-hoc comparisons.

RESULTS

BD patients exhibited higher fractional anisotropy (FA) in fronto-ponto-cerebellar tracts bilaterally compared to HC. Subphenotype-specific FA profiles were identified within the BD cohort. Regarding PP subgroups, we found FA changes in a) left contralateral fronto-ponto-cerebellar tract (depressive-PP > HC) and b) contralateral/ipsilateral fronto-ponto-cerebellar tracts bilaterally (manic-PP > HC). Regarding OP subgroups, we observed FA changes in a) left/right contralateral fronto-ponto-cerebellar tracts (depressive-OP > HC) and b) all fronto-ponto-cerebellar, most parieto-ponto-cerebellar and right contralateral occipito-ponto-cerebellar tracts (manic-OP>HC). In general, greater and more widespread cerebro-cerebellar changes were observed in manic-OP patients than in depressive-OP patients compared to HC. Manic-OP showed higher FA compared to depressive-OP patients in several afferent WM tracts. No GM differences were identified between BD and HC and across BD subgroups.

CONCLUSIONS

Our findings highlight fronto-ponto-cerebellar connectivity alterations in euthymic BD. Polarity-related subphenotypes have distinctive cerebro-cerebellar WM signatures with potential clinical and pathobiological implications.

Comorbidity of obsessive-compulsive disorder in bipolar spectrum disorders: Systematic review and meta-analysis of its prevalence

BACKGROUND

Obsessive-compulsive disorder (OCD) is often comorbid with Bipolar Disorder (BD), complicating its presentation and management. OCD prevalence rates in BD vary widely across studies and recent meta-analyses.

OBJECTIVE

We performed a comprehensive systematic review and meta-analysis of studies reporting cross-sectional or lifetime OCD prevalence in BD, assessed by meta-regression various determinants of estimated prevalence and compared it with major depressive disorder (MDD) patients and general population subjects included in extracted studies.

METHODS

Relevant articles published up to January 2019 in PubMed/MEDLINE were retrieved. Prevalence rates underwent Freeman-Tukey double arcsine transformation before meta-analysis.

RESULTS

We included 29 studies reporting cross-sectional prevalence (N = 6109) and 39 studies reporting lifetime prevalence (N = 8205); eight studies reported both. The pooled lifetime and cross-sectional prevalence of comorbid OCD in BD was estimated at 10.9% (95% CI: 7.8-14.4%) and 11.2% (7.6-15.3%), respectively, in the random-effects model. Respective estimates in the general population were 2.5% and 1.6%. Study setting (epidemiological or clinical), diagnostic criteria and procedures, gender, BD subtype and remission status could not explain heterogeneity of prevalence estimates in meta-regressions. Age had a small yet significant negative correlation with lifetime prevalence. OCD prevalence in BD was not significantly different than in MDD.

LIMITATIONS

Search was limited to English-language literature.

CONCLUSIONS

Lifetime OCD prevalence in BD was 4.4 times higher than in the general population. Cross-sectional prevalence was as high as lifetime, suggesting that OCD in BD is more chronic/ persistent than in the general population, where cross-sectional stands at about two thirds the lifetime prevalence.

Bipolar spectrum disorder: What evidence for pharmacological treatment? A systematic review

BACKGROUND AND OBJECTIVES

Bipolar spectrum disorder (BSD) is an extended concept of bipolar disorder (BD) that includes conditions that do not fulfill the criteria. There is no recommendation today about its treatment. We reviewed relevant literature focusing on pharmacological treatments, looking for high-strength evidence leading to guidelines.

METHODOLOGY

A literature search was conducted using MedLine / PubMed database and Google Scholar up to September 2018. Search words were related to BSD and pharmacological treatment.

RESULTS

The literature search yielded 621 articles. Out of these, 35 articles met our selection criteria. There was limited high quality data. Only one randomized control trial (RCT) and one randomized open label trial were found. Most studies used different definition of BSD.

CONCLUSIONS

There is a considerable lack of data and no evidence supporting efficacy of pharmacological treatment for BSD. There is a need for a consensus on the definition of BSD and more evidence studies to evaluate drug's effectiveness in this condition.

Modeling human temperament and character on the basis of combined theoretical approaches

BACKGROUND

Although there are several models on the structure of human temperament, character and personality, the majority follow a single approach, providing a unilateral and overly theoretical construct which is unsuitable for clinical application. The current study aimed to develop a complex and comprehensive model of temperament and character by empirically combining relevant existing theories.

METHODS

The study included 734 healthy general population subjects aged 40.80 ± 11.48 years, who completed the TEMPS-A, TCI and NEO-PI-3 questionnaires. Data were analyzed in a multistep approach using Exploratory Factor analysis and forward stepwise linear regression.

RESULTS

The results yielded two highest order factors (Self and Self-Environment Interaction), six middle order factors (Emotional Self, Cognitive Self, Social Emotionality, Emotional and Cognitive Control, Ethical Emotionality and Behavior, Social Emotionality and Behavior) and 12 factors at the bottom (Ego Resiliency, Ego Strength, Intrapersonal Emotion, Personal Space Cognition, Interpersonal Cognition, Emotional Creativity, Externalized Interpersonal Emotion, Internalized Interpersonal Emotion, Emotional Motivation, Self-Discipline, Ethical Values and Ethical Behavior).

CONCLUSIONS

The current study developed a complex hierarchical model of temperament and character on the basis of empirical data from several temperament theories. An important feature of the new temperamental model is the frequent admixture of emotional and cognitive processes within the same module. This model expands the field to include elements probably corresponding to meta-cognition mechanisms and complex interactions between affective and cognitive control, which may provide useful in understanding and treating affective disorders as well.

Prevalence and treatment of panic disorder in bipolar disorder: systematic review and meta-analysis

QUESTION

Recent data suggest that anxiety disorders are as often comorbid with bipolar disorder (BD) as with unipolar depression. The literature on panic disorder (PD) comorbid with BD has been systematically reviewed and subject to meta-analysis.

STUDY SELECTION AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were thoroughly followed for literature search, selection and reporting of available evidence. The variance-stabilising Freeman-Tukey double arcsine transformation was used in the meta-analysis of prevalence estimates. Both fixed-effect and random-effects models with inverse variance method were applied to estimate summary effects for all combined studies. Heterogeneity was assessed and measured with Cochran's Q and I2 statistics.

FINDINGS

Overall, 15 studies (n=3391) on cross-sectional prevalence and 25 independent lifetime studies (n=8226) were used to calculate pooled estimates. The overall random-effects point prevalence of PD in patients with BD, after exclusion of one potential outlier study, was 13.0% (95% CI 7.0% to 20.3%), and the overall random-effects lifetime estimate, after exclusion of one potential outlier study, was 15.5% (95% CI 11.6% to 19.9%). There were no differences in rates between BD-I and BD-II. Significant heterogeneity (I2 >95%) was found in both estimates.

CONCLUSIONS

Estimates that can be drawn from published studies indicate that the prevalence of PD in patients with BD is higher than the prevalence in the general population. Comorbid PD is reportedly associated with increased risk of suicidal acts and a more severe course. There is no clear indication on how to treat comorbid PD in BD. Findings from the current meta-analysis confirm the highly prevalent comorbidity of PD with BD, implicating that in patients with BD, PD might run a more chronic course.