The profile and familiality of personality traits in mood disorder families

Comparative Analysis of Personality Traits in Major Depressive Disorder and Bipolar Disorder: Impact, Differences, and Associations with Symptoms

Purpose

This cross-sectional study aimed to compare the personality traits of patients with major depressive disorder (MDD) and bipolar disorder (BD) with those of healthy individuals. The goal was to gain insight into the potential impact of personality traits on the development and manifestation of mood disorders.

Methods

One hundred seventy-eight patients with mood disorders were analyzed as either MDD or BD, with each group containing euthymic and depressive members: e-MDD, d-MDD, e-BD, and d-BD. Mood status was assessed using the Young Mania Rating Scale (YMRS), and the 17-item Hamilton Depression Rating Scale (HAMD-17). Ninety-five healthy individuals served as controls. Personality traits were assessed with the Eysenck Personality Questionnaire.

Results

The scores for neuroticism in the patient groups were comparable, but each group had higher scores compared to the control group (P < 0.001). Each patient group exhibited significantly lower scores for extraversion compared to the control group, with e-MDD, d-MDD, and d-BD showing particularly notable differences (P < 0.001); these groups scored significantly lower than the e-BD (P = 0.041, 0.009, 0.038). In patients with BD, there was an inverted association between extraversion score and HAMD total score (P = 0.010, r = -0.27), and a positive association with the YMRS total score (P = 0.022, r = 0.24). In the MDD group, there was a positive association between the neuroticism score and HAMD total score (P = 0.021, r = 0.25).

Conclusion

Patients with mood disorders are characterized by lower extraversion and higher neuroticism. Level of neuroticism associated with depression severity in MDD. Patients with BD may be more extraverted, but their extraversion can be affected by depressive episodes. Extraversion may be a feature of BD, and may differentiate BD from MDD. Personality traits are related to disease diathesis and state, and shaped by symptom manifestations.

The association of personality polygenic risk score, psychosocial protective factors and suicide attempt in mood disorder

Some personality traits, especially neuroticism, has been found to be associated with suicide attempt (SA) in mood disorder patients. The present study explored the association between personality traits and SA using polygenic risk scores (PRS) for personality among patients with mood disorders. We also investigated the effects of a variety of psychosocial variables on SA. Patients with bipolar disorder (BPD, N = 841) and major depressive disorder (MDD, N = 710) were recruited from hospitals in Taiwan. Lifetime SA and information on psychosocial factors was collected. We calculated the PRS of neuroticism and extraversion. A trend test for SA was performed across quartiles of the PRS for neuroticism and extraversion, and logistic regression analyses were performed to examine the associations between psychosocial factors and SA, accounting for the PRS of personality traits. The prevalence of SA was higher in MDD than in BPD patients. The risk of SA was elevated in MDD patients with a higher quintile of PRS in neuroticism and a lower quintile of PRS in extraversion. The multiple regression analysis results demonstrated that later age of onset, higher family support and resilience, and lower overall social support were protective factors against SA. From the perspective of suicide prevention efforts, strengthening family support and conducting resilience training for patients with mood disorders may be beneficial interventions in clinical settings.

The effects of childhood trauma on personality in unaffected first-degree relatives of patients with major depressive disorder

ABSTRAC

OBJECTIVES: This study aimed to preliminarily and exploratorily examine the associations between childhood trauma (CT), its subtypes, and personality traits among unaffected first-degree relatives (FDR, children, or siblings) of patients with major depressive disorder (MDD).

METHODS

The study sample included three subgroups: MDD patients (N = 85), Patients' FDRs (N = 35), and healthy control individuals (HC, N = 89). The Childhood Trauma Questionnaire (CTQ) was used to assess childhood trauma and the Eysenck Personality Questionnaire was used to assess personality traits.

RESULTS

Significant differences were found in a few personality traits (p < 0.05 for extraversion, neuroticism, and psychoticism) among MDD patients, FDR, and HC, and there were no significant differences between HC and FDR. In the FDR group, compared with those without CT, participants with CT scored significantly higher for neuroticism (N) (F = 3.246, p = 0.046). CT was significantly associated with N, psychoticism (P) and Lie (L), and the strongest association was between CT total score and N. Significantly positive correlations were found between N and sexual abuse (SA) (r = 0.344, p = 0.043), emotional neglect (EN) (r = 0.394, p = 0.019), physical neglect (PN) (r = 0.393, p = 0.019), and CTQ total score (r = 0.452, p = 0.006); between P and CTQ total score (r = 0.336, p = 0.049); and significant negative correlations were found between L and EN (r = -0.446, p = 0.007), CTQ total score (r = -0.375, p = 0.027).

CONCLUSION

In unaffected FDRs, there were significant associations between childhood trauma and a few personality traits, including neuroticism, psychoticism, and lie, and emotional neglect was significantly associated with neuroticism.

Modeling heritability of temperamental differences, stress reactivity, and risk for anxiety and depression: Relevance to research domain criteria (RDoC)

Animal models provide important tools to study biological and environmental factors that shape brain function and behavior. These models can be effectively leveraged by drawing on concepts from the National Institute of Mental Health Research Domain Criteria (RDoC) Initiative, which aims to delineate molecular pathways and neural circuits that underpin behavioral anomalies that transcend psychiatric conditions. To study factors that contribute to individual differences in emotionality and stress reactivity, our laboratory utilized Sprague-Dawley rats that were selectively bred for differences in novelty exploration. Selective breeding for low versus high locomotor response to novelty produced rat lines that differ in behavioral domains relevant to anxiety and depression, particularly the RDoC Negative Valence domains, including acute threat, potential threat, and loss. Bred Low Novelty Responder (LR) rats, relative to their High Responder (HR) counterparts, display high levels of behavioral inhibition, conditioned and unconditioned fear, avoidance, passive stress coping, anhedonia, and psychomotor retardation. The HR/LR traits are heritable, emerge in the first weeks of life, and appear to be driven by alterations in the developing amygdala and hippocampus. Epigenomic and transcriptomic profiling in the developing and adult HR/LR brain suggest that DNA methylation and microRNAs, as well as differences in monoaminergic transmission (dopamine and serotonin in particular), contribute to their distinct behavioral phenotypes. This work exemplifies ways that animal models such as the HR/LR rats can be effectively used to study neural and molecular factors driving emotional behavior, which may pave the way toward improved understanding the neurobiological mechanisms involved in emotional disorders.

Reinforcement sensitivity, depression and anxiety: A meta-analysis and meta-analytic structural equation model

Reinforcement Sensitivity Theory (RST) posits that individual differences in reward and punishment processing predict differences in cognition, behavior, and psychopathology. We performed a quantitative review of the relationships between reinforcement sensitivity, depression and anxiety, in two separate sets of analyses. First, we reviewed 204 studies that reported either correlations between reinforcement sensitivity and self-reported symptom severity or differences in reinforcement sensitivity between diagnosed and healthy participants, yielding 483 effect sizes. Both depression (Hedges' g = .99) and anxiety (g = 1.21) were found to be high on punishment sensitivity. Reward sensitivity negatively predicted only depressive disorders (g = -.21). More severe clinical states (e.g., acute vs remission) predicted larger effect sizes for depression but not anxiety. Next, we reviewed an additional 39 studies that reported correlations between reinforcement sensitivity and both depression and anxiety, yielding 156 effect sizes. We then performed meta-analytic structural equation modeling to simultaneously estimate all covariances and control for comorbidity. Again we found punishment sensitivity to predict depression (β = .37) and anxiety (β = .35), with reward sensitivity only predicting depression (β = -.07). The transdiagnostic role of punishment sensitivity and the discriminatory role of reward sensitivity support a hierarchical approach to RST and psychopathology.

Risk profiles of personality traits for suicidality among mood disorder patients and community controls

OBJECTIVE

To examine the associations between personality traits and suicidal ideation (SI) and attempt (SA) in mood disorder patients and community controls.

METHOD

We recruited 365 bipolar, 296 major depressive disorder patients, and 315 community controls to assess their lifetime suicidality. Participants filled out self-reported personality questionnaires to collect data of personality traits, including novelty seeking (NS), harm avoidance (HA), extraversion (E), and neuroticism (N). We used logistic regression models adjusted for diagnoses to analyze combinational effects of personality traits on the risk of suicide. Additionally, radar charts display personality profiles for suicidal behaviours by groups.

RESULTS

All personality traits were associated with the risk of suicidality with various effect size, except for E that showed protective effect. High N or HA had prominent and independent risk effects on SI and SA. Combinations of high N and low E, or high HA and NS were the risk personality profiles for suicidality. Higher N scores further distinguished SA from SI in mood disorder patients.

CONCLUSION

Introvert personality traits showed independent risk effects on suicidality regardless of diagnosis status. Among high-risk individuals with suicidal thoughts, higher neuroticism tendency is further associated with increased risk of suicide attempt.

Personality traits in bipolar disorder and influence on outcome

BACKGROUND

The aim was to investigate the personality profile of bipolar disorder I and II, and healthy controls, and to study whether personality influences the course of bipolar disorder.

METHODS

One hundred ten patients with bipolar disorder I, 85 patients with bipolar disorder II, and 86 healthy individuals had their personality profile assessed using the Swedish universities Scales of Personality (SSP), an instrument developed to explore personality-related vulnerabilities and correlates of psychiatric disorders. Patients were followed prospectively for 2 years. To assess the impact of Neuroticism, Aggressiveness, and Disinhibition on illness course, we performed logistic regressions with the outcome variables mood episodes (depressive, hypo/manic, mixed), suicide attempts, violence, and the number of sick leave days.

RESULTS

Bipolar disorder I and II demonstrated higher global measures of Neuroticism, Aggressiveness, and Disinhibition as compared with healthy controls. A third of the patients scored ≥1 SD above the population-based normative mean on the global neuroticism measure. The two subtypes of bipolar disorder were, however, undistinguishable on all of the personality traits. In the unadjusted model, higher neuroticism at baseline predicted future depressive episodes and suicide attempts/violent behavior, but this association disappeared when adjusting for baseline depressive symptoms as assessed with MADRS.

CONCLUSIONS

A significant minority of the patients scored ≥1 SD above the population mean on the global measures of Neuroticism, Aggressiveness and Disinhibition; scores this high are usually evident clinically. Yet, the personality profile does not seem to have prognostic value over a 2-year period.

Personality Characteristics as Predictive Factors for the Occurrence of Depressive Disorder

BACKGROUND:

The depressive disorder is one of the most frequent mental disorders, which is often associated with severe dysfunctionality. Personality traits are considered as important factors for the occurrence of depressive disorder.

AIM:

To determine the specificity of personality dimensions as predictive factors of depressive disorder.

METHODS:

This research was conducted at the University Psychiatric Clinic Skopje as a “case-control” study. TCI-R (temperament and character inventory – revised) was used as the main research instrument.

RESULTS:

There are specific personality traits expressed through high scores of Harm Avoidance and low scores of Self –Directedness traits as predictive factors related to an incidence of the depressive disorder.

CONCLUSION:

The results of this study show that certain personal traits, and more specific HA and SD, are with a specific predictability of the depressive disorder.

Adult attention-deficit/hyperactivity disorder in major depressed and bipolar subjects: role of personality traits and clinical implications

A significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and affective disorders has been consistently reported in adults. Less data regarding the role of personality traits and the influence of ADHD co-occurrence on clinical characteristics and outcome of mood disorders are currently available. One hundred and six remitted major depressed, 102 euthymic bipolar subjects, and 120 healthy controls, homogeneous with respect to demographic characteristics, were included in the study. ADHD diagnosis was based on DSM-IV-TR criteria. Childhood and adult ADHD features were measured with the Wender Utah Rating Scale, the Adult ADHD Self-rating Scale, and the Brown Attention-Deficit Disorder Scale. The Revised NEO Personality Inventory was also administered to the clinical groups, in order to investigate personality dimensions. The occurrence of adult ADHD in subjects with bipolar disorders (BD) or major depressive disorder (MDD) was 15.7 and 7.5 %, respectively, compared to 3.3 % in healthy controls (HC). Significant associations (p < .001) between personality traits (neuroticism, conscientiousness, and extraversion) and ADHD features were observed. Logistic regression analysis of all clinical subjects (n = 208) showed that those with lower levels of neuroticism (OR = 1.031; p = .025) had a lower frequency of ADHD comorbidity. The present study emphasizes the close relationship between affective disorders, especially BD, and ADHD in adults. Our findings support the need to assess subjects with mood disorders in the clinical setting for possible coexisting ADHD and to further investigate personality traits to better understand the etiology of affective disorders and ADHD co-occurrence.

Identification of novel loci for bipolar I disorder in a multi-stage genome-wide association study

OBJECTIVE

Identification of genetic variants that influence bipolar I disorder (BPD-I) through genome-wide association (GWA) studies is limited in Asian populations. The current study aimed to identify novel common variants for BPD-I in an ethnically homogeneous Taiwanese sample using a multi-stage GWA study design.

METHOD

At the discovery stage, 200 BPD-I patients and 200 controls that combined to form 16 pools were genotyped with 1 million markers. Utilizing a newly developed rank-based method, top-ranked markers were selected. After validation with individual genotyping, a fine-mapping association study was conducted to identify associated loci using 240 patients and 240 controls. At the last stage, independent samples were collected (351 cases and 341 controls) for replication.

RESULTS

Among the top-ranked markers from the discovery stage, eight genes and 15 individual SNPs were evaluated in the fine-mapping stage. At this stage, rs7619173, which is not in a gene coding region, showed the most significant association (P = 2 ∗ 10(-5)) with BPD-I. Four genes had empirical P-values<0.05, including KCNH7 (P = 0.0047), MYST4 (P = 0.0047), NRXN3 (P = 0.0095), and SEMA3D (P = 0.037). For markers genotyped in replication samples, rs7619173 exhibited a significant association (P(combined) = 2 ∗ 10(-4)) after multiple testing correction, while markers rs11001178 (MYST4) and rs2217887 (NRXN3) showed weak associations (P(combined) = 0.02) with BPD-I.

CONCLUSION

A multi-stage GWA design has the potential to uncover the underlying pathogenesis of a complex trait. Findings in the present study highlight three loci that warrant further investigation for bipolar.

The sense of incompleteness as a motivator of obsessive-compulsive symptoms: an empirical analysis of concepts and correlates

Contemporary models of obsessive-compulsive disorder emphasize the importance of harm avoidance (HA) and related dysfunctional beliefs as motivators of obsessive-compulsive (OC) symptoms. Recently, there has been a resurgence of interest in Janet's (1908) concept of incompleteness (INC) as another potentially important motivator. Contemporary investigators define INC as the sense that one's actions, intentions, or experiences have not been properly achieved. Janet defined INC more broadly to include alexithymia, depersonalization, derealization, and impaired psychological mindedness. We conducted two studies to address four issues: (a) the clinical correlates of INC; (b) whether INC and HA are distinguishable constructs; (c) whether INC predicts OC symptoms after controlling for HA; and (d) the relative merits of broad versus narrow conceptualizations of INC. Study 1 was a meta-analysis of the clinical correlates of narrowly defined INC (16 studies, N=5,940). INC was correlated with all types of OC symptoms, and was more strongly correlated with OC symptoms than with general distress. Study 2 (N=534 nonclinical participants) showed that (a) INC and HA were strongly correlated but factor analytically distinguishable; (b) INC statistically predicted all types of OC symptoms even after controlling for HA; and (c) narrow INC was most strongly correlated with OC symptoms whereas broad INC was most strongly correlated with general distress. Although the findings are limited by being correlational in nature, they support the hypothesis that INC, especially in its narrow form, is a motivator of OC symptoms.

Identifying Potential Regions of Copy Number Variation for Bipolar Disorder

Bipolar disorder is a complex psychiatric disorder with high heritability, but its genetic determinants are still largely unknown. Copy number variation (CNV) is one of the sources to explain part of the heritability. However, it is a challenge to estimate discrete values of the copy numbers using continuous signals calling from a set of markers, and to simultaneously perform association testing between CNVs and phenotypic outcomes. The goal of the present study is to perform a series of data filtering and analysis procedures using a DNA pooling strategy to identify potential CNV regions that are related to bipolar disorder. A total of 200 normal controls and 200 clinically diagnosed bipolar patients were recruited in this study, and were randomly divided into eight control and eight case pools. Genome-wide genotyping was employed using Illumina Human Omni1-Quad array with approximately one million markers for CNV calling. We aimed at setting a series of criteria to filter out the signal noise of marker data and to reduce the chance of false-positive findings for CNV regions. We first defined CNV regions for each pool. Potential CNV regions were reported based on the different patterns of CNV status between cases and controls. Genes that were mapped into the potential CNV regions were examined with association testing, Gene Ontology enrichment analysis, and checked with existing literature for their associations with bipolar disorder. We reported several CNV regions that are related to bipolar disorder. Two CNV regions on chromosome 11 and 22 showed significant signal differences between cases and controls (p < 0.05). Another five CNV regions on chromosome 6, 9, and 19 were overlapped with results in previous CNV studies. Experimental validation of two CNV regions lent some support to our reported findings. Further experimental and replication studies could be designed for these selected regions.

Individual differences in novelty seeking predict subsequent vulnerability to social defeat through a differential epigenetic regulation of brain-derived neurotrophic factor expression

Some personality traits, including novelty seeking, are good predictors of vulnerability to stress-related mood disorders in both humans and rodents. While high-novelty-seeking rats [high responders (HRs)] are vulnerable to the induction of depressive-like symptoms by social defeat stress, low-novelty-seeking rats [low responders (LRs)] are not. Here, we show that such individual differences are critically regulated by hippocampal BDNF. While LR animals exhibited an increase in BDNF levels following social defeat, HR individuals did not. This difference in hippocampal BDNF expression promoted the vulnerability of HR and the resilience of LR rats. Indeed, preventing activation of BDNF signaling by infusing the BDNF scavenger TrkB-Fc into the dentate gyrus of the hippocampus of LR rats led to social defeat-induced social avoidance, whereas its activation in HR rats by the TrkB agonist 7,8-dihydroxyflavone promoted social approach. Along with the changes in BDNF expression following defeat, we report in LR animals a downregulation of the inactive BDNF receptor TrkB.T1, associated with an activation of CREB through Akt-mediated signaling, but not MSK1-mediated signaling. In HR animals, none of these molecules were affected by social defeat. Importantly, the BDNF upregulation involved an epigenetically controlled transcription of bdnf exon VI, associated with a coherent regulation of relevant epigenetic factors. Altogether, our data support the importance of hippocampal BDNF regulation in response to stressful events. Moreover, we identify a specific and adaptive regulation of bdnf exon VI in the hippocampus as a critical regulator of stress resilience, and strengthen the importance of epigenetic factors in mediating stress-induced adaptive and maladaptive responses in different individuals.