Exploration of mood spectrum symptoms during a major depressive episode: The impact of contrapolarity-Results from a transdiagnostic cluster analysis on an Italian sample of unipolar and bipolar patients

Left Ventrolateral Prefrontal Cortical Activity During Reward Expectancy and Mania Risk

Importance

Mania/hypomania is the pathognomonic feature of bipolar disorder (BD). As BD is often misdiagnosed as major depressive disorder (MDD), replicable neural markers of mania/hypomania risk are needed for earlier BD diagnosis and pathophysiological treatment development.

Objective

To replicate the previously reported positive association between left ventrolateral prefrontal cortex (vlPFC) activity during reward expectancy (RE) and mania/hypomania risk, to explore the effect of MDD history on this association, and to compare RE-related left vlPFC activity in individuals with and at risk of BD.

Design, Setting, and Participants

This cross-sectional study was conducted from July 2014 to December 2023 at the University of Pittsburgh, Pittsburgh, Pennsylvania. Three samples were formed comprising young adults (aged 18 to 30 years) without BD and with a range of subsyndromal-syndromal affective and anxiety psychopathologies, including a new sample and 2 test samples from our previous research; a sample of individuals aged 18 to 30 years with euthymic BD was also included. All participants were recruited from the community through advertising.

Exposures

Functional magnetic resonance imaging during an RE task.

Main Outcomes and Measures

New sample: whole-brain activity during RE regressed to the Mood Spectrum Self-Report Lifetime Questionnaire (MOODS-SR-L) manic domain score in all participants and in those without history of MDD and RE-related whole-brain activity regressed to the MOODS-SR-L depressive domain score to determine specificity to mania/hypomania risk. Test samples: these associations were examined using parameter estimates of activity extracted from respective masks created from activity in the new sample. A tertile split of MOODS-SR-L manic domain score divided the new sample into 3 mania/hypomania risk groups. Comparison of RE-related activity (extracted parameter estimates) was performed in risk groups and individuals with BD.

Results

Among the 113 individuals in the new sample, 73 were female, and the mean (SD) age was 23.88 (3.32) years. In each of the test samples, there were 52 individuals (39 female; mean [SD] age, 21.94 [2.12] years) and 65 individuals (47 female; mean [SD] age, 21.39 [2.11] years). The euthymic BD group had 37 individuals (30 female; mean [SD] age, 25.12 [3.81] years). In the new sample, 8 clusters of RE-related activity, including left vlPFC activity, showed a positive association with mania/hypomania risk, which remained after excluding individuals with MDD history and was specific to mania/hypomania risk. In the test samples, this association was shown in test sample 1 only (β, 0.21; 95% CI, 0.08-0.35; P = .002; q(false discovery rate [FDR]), 0.006; R2, 0.04). Test sample 2 had a higher proportion with MDD history (49 of 65 [75.3%] compared to 31 of 52 [59.6%] in sample 1). Combining individuals without history of MDD in both test samples replicated the association (β, 0.32; 95% CI, 0.08-0.58; P = .01; q[FDR], 0.023; R2, 0.02). RE-related left vlPFC activity was significantly greater in individuals at highest risk vs lowest (Cohen d, 1.01; 95% CI, 0.29-0.79; P < .001) and medium (Cohen d, 0.59; 95% CI, 0.12-0.63; P = .004) risk, as well as the euthymic BD group (Cohen d, 0.54; 95% CI, 0.07-0.58; P = .01), potentially due to medication effects.

Conclusion and Relevance

Elevated RE-related left vlPFC activity was associated with mania/hypomania risk and attenuated by MDD history. These findings provide a neural target to help develop pathophysiological interventions for individuals with or at risk of mania/hypomania.

Sex differences in neural responses to emotional facial expressions are associated with lifetime depression and mania risk

INTRODUCTION

No studies systematically examined sex differences in neural mechanisms underlying depression and mania/hypomania risk.

METHOD

80 females and 35 males, n = 115(age21.6±1.90) were scanned using 3TfMRI during an implicit emotional-faces task. We examined neural activation to all emotional faces versus baseline, using an anatomical region-of-interest mask comprising regions supporting emotion and salience processing. Sex was a covariate. Extracted parameter estimates(FWE < 0.05,k > 15), age, IQ and their sex interactions were independent variables(IV) in two penalized regression models: dependent variable either MOODS-SR-lifetime, depressive or manic domain score as measures of mania and depression risk. Subsequent Poisson regression models included the non-zero variables identified in the penalized regression models. We tested each model in 2 independent samples. Test sample-I,n = 108(21.6 ± 2.09 years,males/females = 33/75); Test sample-II,n = 93(23.7 ± 2.9 years,males/females = 31/62).

RESULTS

Poisson regression models yielded significant relationships with depression and mania risk: Positive correlations were found between right fusiform activity and depression(beta = 0.610) and mania(beta = 0.690) risk. There was a significant interaction between sex and right fusiform activity(beta = -0.609) related to depression risk, where females had a positive relationship than; and a significant interaction(beta = 0.743) between sex and left precuneus activity related to mania risk, with a more negative relationship in females than males. All findings were replicated in the test samples(qs < 0.05,FDR).

LIMITATIONS

No longitudinal follow-up.

CONCLUSION

Greater visual attention to emotional faces might underlie greater depression and mania risk, and confer greater vulnerability to depression in females, because of heightened visual attention to emotional faces. Females have a more negative relationship between mania risk and left precuneus activity, suggesting heightened empathy might be associated with reduced mania/hypomania risk in females more than males.

Patterns of Neural Network Functional Connectivity Associated With Mania/Hypomania and Depression Risk in 3 Independent Young Adult Samples

Importance

Mania/hypomania is the pathognomonic feature of bipolar disorder (BD). Established, reliable neural markers denoting mania/hypomania risk to help with early risk detection and diagnosis and guide the targeting of pathophysiologically informed interventions are lacking.

Objective

To identify patterns of neural responses associated with lifetime mania/hypomania risk, the specificity of such neural responses to mania/hypomania risk vs depression risk, and the extent of replication of findings in 2 independent test samples.

Design, Setting, and Participants

This cross-sectional study included 3 independent samples of young adults aged 18 to 30 years without BD or active substance use disorder within the past 3 months who were recruited from the community through advertising. Of 603 approached, 299 were ultimately included and underwent functional magnetic resonance imaging at the University of Pittsburgh, Pittsburgh, Pennsylvania, from July 2014 to May 2023.

Main Outcomes and Measures

Activity and functional connectivity to approach-related emotions were examined using a region-of-interest mask supporting emotion processing and emotional regulation. The Mood Spectrum Self-Report assessed lifetime mania/hypomania risk and depression risk. In the discovery sample, elastic net regression models identified neural variables associated with mania/hypomania and depression risk; multivariable regression models identified the extent to which selected variables were significantly associated with each risk measure. Multivariable regression models then determined whether associations in the discovery sample replicated in both test samples.

Results

A total of 299 participants were included. The discovery sample included 114 individuals (mean [SD] age, 21.60 [1.91] years; 80 female and 34 male); test sample 1, 103 individuals (mean [SD] age, 21.57 [2.09] years; 30 male and 73 female); and test sample 2, 82 individuals (mean [SD] age, 23.43 [2.86] years; 48 female, 29 male, and 5 nonbinary). Associations between neuroimaging variables and Mood Spectrum Self-Report measures were consistent across all 3 samples. Bilateral amygdala-left amygdala functional connectivity and bilateral ventrolateral prefrontal cortex-right dorsolateral prefrontal cortex functional connectivity were positively associated with mania/hypomania risk: discovery omnibus χ2 = 1671.7 (P < .001); test sample 1 omnibus χ2 = 1790.6 (P < .001); test sample 2 omnibus χ2 = 632.7 (P < .001). Bilateral amygdala-left amygdala functional connectivity and right caudate activity were positively associated and negatively associated with depression risk, respectively: discovery omnibus χ2 = 2566.2 (P < .001); test sample 1 omnibus χ2 = 2935.9 (P < .001); test sample 2 omnibus χ2 = 1004.5 (P < .001).

Conclusions and Relevance

In this study of young adults, greater interamygdala functional connectivity was associated with greater risk of both mania/hypomania and depression. By contrast, greater functional connectivity between ventral attention or salience and central executive networks and greater caudate deactivation were reliably associated with greater risk of mania/hypomania and depression, respectively. These replicated findings indicate promising neural markers distinguishing mania/hypomania-specific risk from depression-specific risk and may provide neural targets to guide and monitor interventions for mania/hypomania and depression in at-risk individuals.

Effect of affective temperament on illness characteristics of subjects with bipolar disorder and major depressive disorder

BACKGROUND

Affective temperaments represent the stable, biologically determined substrates of mood disorders. The relationship between affective temperaments and bipolar disorder (BD) or major depressive disorder (MDD) has been described. However, the strength of such relationship should be tested while considering other factors influencing the diagnosis of BD/MDD. Literature also lacks a comprehensive description of the interplay between affective temperament and characteristics of mood disorders. The aim of the present study is to address these issues.

METHODS

This is a multicentric observational study including 7 Italian university sites. Five-hundred-fifty-five euthymic subjects with BD/MDD were enrolled and further divided in those with hyperthymic (Hyper, N = 143), cyclothymic (Cyclo, N = 133), irritable (Irr, N = 49), dysthymic (Dysth, N = 155), and anxious (Anx N = 76) temperaments. Linear, binary, ordinal and logistic regressions were performed to assess the association between affective temperaments and i) diagnosis of BD/MDD; ii) characteristics of illness severity and course.

RESULTS

Hyper, Cyclo and Irr were more likely to be associated with BD, together with earlier age of onset and presence of a first-degree relative with BD. Anx and Dysth were more associated with MDD. Differences in association between affective temperaments and characteristics of BD/MDD were observed for hospital admissions, phase-related psychotic symptoms, length and type of depression, comorbidity and pharmacological intake.

LIMITATIONS

Small sample size, cross-sectional design, recall biases.

CONCLUSION

Specific affective temperaments were associated to certain characteristics of illness severity and course of BD or MDD. Evaluation of affective temperaments might help a deeper understanding of mood disorders.

Eveningness chronotype and depressive affective temperament associated with higher high-sensitivity C-reactive protein in unipolar and bipolar depression

BACKGROUND

Several studies investigated the role of inflammation in the etiopathogenesis of mood disorders. The aim of our cross-sectional study is evaluating baseline high-sensitivity C-reactive-protein (hsCRP) levels in a cohort of unipolar and bipolar depressive inpatients, in relation with psychopathological, temperamental and chronotype features.

METHODS

Among 313 screened inpatients, we retrospectively recruited 133 moderate-to-severe depressive patients who were assessed for hsCRP levels, chronotype with Morningness-Eveningness Questionnaire (MEQ) and affective temperament with Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS).

LIMITATIONS

The cross-sectional and retrospective design of the study, the small sample size, the exclusion of hypomanic, maniac and euthymic bipolar patients.

RESULTS

hsCRP levels were significantly higher among those with previous suicide attempt (p = 0.05), death (p = 0.018) and self-harm/self-injury thoughts (p = 0.011). Linear regression analyses, adjusted for all covariates, demonstrated that higher scores at the TEMPS-M depressive, while lower scores at the hyperthymic and irritable affective temperaments [F = 88.955, R² = 0.710, p < 0.001] and lower MEQ scores [F = 75.456, R² = 0.405, p < 0.001] statistically significantly predicted higher hsCRP.

CONCLUSION

Eveningness chronotype and a depressive affective temperament appeared to be associated with higher hsCRP levels during moderate-to-severe unipolar and bipolar depression. Further longitudinal and larger studies should better characterise patients with mood disorders by investigating the influence of chronotype and temperament.