The interrelationship of neuroticism, sex, and stressful life events in the prediction of episodes of major depression

Prediction of major depressive episodes and suicide-related ideation over a 3-year interval among Japanese undergraduates

Background

Suicide has been a leading cause of death among young adult populations in Japan. The aim of this study was to predict major depressive episodes (MDEs) and suicide-related ideation among university students using the Patient Health Questionnaire-9 (PHQ-9) and the Temperament and Character Inventory (TCI).

Methods

The subjects were 2194 university students who completed the PHQ-9 and TCI in the 1st year (T1) and the PHQ-9 in the 4th year (T2) of university. Multiple logistic regression analysis was performed to predict MDEs and suicide-related ideation at T2. Moreover, recursive partitioning analyses were conducted to reveal the future risk of MDEs and suicide-related ideation.

Results

The multiple logistic regression analyses of MDEs and suicide-related ideation at T2 revealed that depressive episodes, suicide-related ideation, and low self-directedness(SD) scores at T1 were significant predictors. The area under the curve of the model for MDEs was 0.858 and that for suicide-related ideation was 0.741. The recursive partitioning analyses revealed that a PHQ-9 summary score ≥15 at T1 predicted a high risk of MDEs at T2 and that both a PHQ-9 summary score ≥5 and a PHQ-9 #9 score ≥1 predicted a high risk of suicide-related ideation at T2.

Conclusions

MDEs, suicide-related ideation, and low SD scores are significant predictors of future MDEs and suicide-related ideation.

The Relationship between Personality Traits with Depressive Symptoms and Suicidal Ideation among Medical Students: A Cross-Sectional Study at One Medical School in Germany

Medical students are at increased risk of experiencing mental health problems. Certain personality traits may be associated with elevated vulnerability to study-related stress and poor mental health. This study aimed to investigate the relationship between such personality traits and mental health outcomes among medical students. We drew on cross-sectional data from 251 medical students who had been enrolled for one-year at a medical school in Germany. Depressive symptoms were measured using the Patient Health Questionnaire-8 (PHQ-8) and suicidal ideation was assessed by item 9 from the Patient Health Questionnaire-9 (PHQ-9). Personality traits were captured using the Business-Focused Inventory of Personality 6 Factors (BIP-6F). Multivariable logistic regression analyses were used to quantify the associations between work-related personality factors and mental health outcomes, controlling for demographic and social factors. Odds ratios (ORs) as outcome measures with 95% confidence intervals (CIs) were used. After controlling for important confounders, medical students who scored highly on Stability had lower odds of depressive symptoms (OR: 0.19, 95% CI: 0.09–0.42, p < 0.001) and suicidality (OR: 0.38, 95% CI: 0.16–0.87, p < 0.05) than those with high scores in other work-related personality factors. Findings also showed that those who scored highly on Dominance had greater odds of depressive symptoms (OR: 2.46, 95% CI: 1.22–4.97), p < 0.01). Work-related personality-informed interventions, which promote students’ mental well-being and reduce academic stress should be considered at various stages of their medical training.

Presence of neuroticism and antidepressant remission rates in late-life depression: results from the Neurobiology of Late-Life Depression (NBOLD) study

ABSTRACTNeuroticism in older adults is common yet understudied, particularly its effects on depression treatment outcomes. We hypothesized that presence of high neuroticism would be associated with lower 12-week remission rates in older depressed sertraline-treated patients. In this longitudinal cohort study, 43 depressed older adults completed the Revised NEO Personality Inventory (NEO PI-R). A study psychiatrist administered the Montgomery Ǻsberg Depression Rating Scale (MADRS), and the Cumulative Illness Rating Scale (CIRS, a measure of medical burden) at baseline, and the MADRS at each clinical visit. All subjects began open-label sertraline treatment and were followed over 12 weeks with clinically indicated flexible dosing and an option to switch antidepressants. We used regression analyses to examine factors related to 12-week remission of depression (MADRS score < 8) and final MADRS score. We found that higher total neuroticism (odds ratio (OR) = 0.963, 95% confidence interval (CI) = 0.928-1.000) and a neuroticism subscale, stress vulnerability (OR = 0.846, 95% CI = 0.728-0.983), were associated with lower likelihood of remission among both the intention-to-treat group and sertraline completers. Findings remained significant after controlling for baseline MADRS and CIRS score. In conclusion, assessment of personality, particularly features of neuroticism, may be important in management of late-life depression. Future studies should determine if depressed patients high in neuroticism may benefit from psychotherapy focusing on emotional regulation and stress management.

Molecular Genetic Analysis Subdivided by Adversity Exposure Suggests Etiologic Heterogeneity in Major Depression

OBJECTIVE

The extent to which major depression is the outcome of a single biological mechanism or represents a final common pathway of multiple disease processes remains uncertain. Genetic approaches can potentially identify etiologic heterogeneity in major depression by classifying patients on the basis of their experience of major adverse events.

METHOD

Data are from the China, Oxford, and VCU Experimental Research on Genetic Epidemiology (CONVERGE) project, a study of Han Chinese women with recurrent major depression aimed at identifying genetic risk factors for major depression in a rigorously ascertained cohort carefully assessed for key environmental risk factors (N=9,599). To detect etiologic heterogeneity, genome-wide association studies, heritability analyses, and gene-by-environment interaction analyses were performed.

RESULTS

Genome-wide association studies stratified by exposure to adversity revealed three novel loci associated with major depression only in study participants with no history of adversity. Significant gene-by-environment interactions were seen between adversity and genotype at all three loci, and 13.2% of major depression liability can be attributed to genome-wide interaction with adversity exposure. The genetic risk in major depression for participants who reported major adverse life events (27%) was partially shared with that in participants who did not (73%; genetic correlation=+0.64). Together with results from simulation studies, these findings suggest etiologic heterogeneity within major depression as a function of environmental exposures.

CONCLUSIONS

The genetic contributions to major depression may differ between women with and those without major adverse life events. These results have implications for the molecular dissection of major depression and other complex psychiatric and biomedical diseases.

The cortisol reactivity threshold model: Direction of trait rumination and cortisol reactivity association varies with stressor severity

Various internalizing risk factors predict, in separate studies, both augmented and reduced cortisol responding to lab-induced stress. Stressor severity appears key: We tested whether heightened trait-like internalizing risk (here, trait rumination) predicts heightened cortisol reactivity under modest objective stress, but conversely predicts reduced reactivity under more robust objective stress. Thus, we hypothesized that trait rumination would interact with a curvilinear (quadratic) function of stress severity to predict cortisol reactivity. Evidence comes from 85 currently non-depressed emerging adults who completed either a non-stressful control protocol (n = 29), an intermediate difficulty Trier Social Stress Test (TSST; n = 26), or a robustly stressful negative evaluative TSST (n = 30). Latent growth curve models evaluated relationships between trait rumination and linear and quadratic effects of stressor severity on the change in cortisol and negative affect over time. Among other findings, a significant Trait Rumination x Quadratic Stress Severity interaction effect for cortisol's Quadratic Trend of Time (i.e., reactivity, B = .125, p = .017) supported the hypothesis. Rumination predicted greater cortisol reactivity to intermediate stress (r_p = .400, p = .043), but blunted reactivity to more robust negative evaluative stress (r_p = -0.379, p = 0.039). Contrasting hypotheses, negative affective reactivity increased independently of rumination as stressor severity increased (B = .453, p = 0.044). The direction of the relationship between an internalizing risk factor (trait rumination) and cortisol reactivity varies as a function of stressor severity. We propose the Cortisol Reactivity Threshold Model, which may help reconcile several divergent reactivity literatures and has implications for internalizing psychopathology, particularly depression.

[A Patient´s Personality: A Frequently Ignored but Important Component in General Medical Practice]

A Patient´s Personality: A Frequently Ignored but Important Component in General Medical Practice Abstract. In general medical practice, a patient's personality is hardly considered and assessed. In this mini-review the author summarises how a comprehensive personality assessment may provide valuable patient information. Prospective effects of personality traits on general lifestyle as well as mental and physical health are presented. In addition, original research is introduced that shows meaningful associations between personality traits, clinical disease markers, and all-cause mortality. These findings are discussed with respect to selected etiological models. The studies illustrate that a personality assessment could be a useful aid for diagnosis, prognosis, and treatment planning.

Brain neuroreceptor density and personality traits: towards dimensional biomarkers for psychiatric disorders

Positron emission tomography has, for 30 years, been used in numerous case-control studies searching for hypothesized differences in the density of neuroreceptor or transporter proteins in psychiatric disorders such as schizophrenia and depression. In most cases, the results have not been conclusive. One reason could be the sizeable interindividual variability in biochemical markers, which in twin studies have shown to emanate from both environmental and genetic factors, leading to low statistical power for the detection of group effects. On the other hand, the same interindividual variability has served as an opportunity for correlative studies on the biological underpinning of behaviour. Using this approach, a series of studies has linked markers for the dopamine and serotonin system to personality traits associated with psychiatric conditions. Based on increasing evidence for the view that many psychopathological states represent extremes of a continuum rather than distinct categories, this research strategy may lead to new biological insights about the vulnerability to and pathophysiology of major psychiatric disorders.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Stressful life events and depressive symptoms in mothers and fathers of young children

BACKGROUND

Parents of young children generally report more depressive symptoms than parents of adult children or people without children, mainly because the presence of young children increases exposure to significant stressors (such as stressful life events). However, most studies on the depressogenic role of stressful life events in parents of young children have focussed on mothers.

METHODS

Using data from 1138 families with young children in Norway, we investigated gender differences in the effect of stressful life events after a child's birth on the development of parental depressive symptoms in 3 follow-ups at child's ages 3-6 years. We also explored if gender differences in disposition (personality) may explain any gender differences in the depressogenic effect of life events.

RESULTS

Nesting parents within families, we found a female gender bias for both neuroticism and depressive symptoms but no gender difference in the number of life events reported. Importantly, the number of stressful life events predicted the level and course of depressive symptoms similarly for mothers and fathers. Personality traits did not change the association between stressful life events and depressive symptoms in either mothers or fathers.

LIMITATIONS

Given the study design, causality cannot be inferred.

CONCLUSIONS

There was no gender difference in the depressogenic effect of stressful life events in our sample. There was no evidence for a female dispositional sensitivity to the depressogenic effect of stressful life events, either. Stressful life events put both mothers and fathers of young children at risk of depression.

Affective temperaments play an important role in the relationship between child abuse and the diagnosis of bipolar disorder

In previous studies, various components such as environmental and genetic factors have been shown to contribute to the development of bipolar disorder (BD). This study investigated how multiple factors, including child abuse, adult life events, and affective temperaments, are interrelated and how they affect the diagnosis of BD. A total of 170 healthy controls and 75 BD patients completed the following self-administered questionnaires: the Patient Health Questionnaire-9 evaluating the severity of depressive symptoms; the Child Abuse and Trauma Scale (CATS) evaluating child abuse; the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego autoquestionnaire (TEMPS-A) evaluating affective temperaments; and the Life Experiences Survey (LES) evaluating negative and positive adult life events. The data were subjected to univariate analysis, multivariable analysis, and structural equation modeling. The structural equation modeling showed that the diagnosis of BD was indirectly predicted by the neglect and sexual abuse scores of the CATS through four affective temperaments (depressive, cyclothymic, irritable, and anxious) of the TEMPS-A and directly predicted by these four affective temperaments. This study suggested that affective temperament plays an important role as a mediator in the influence of child abuse on BD diagnosis.

State of the Science of Neural Systems in Late-Life Depression: Impact on Clinical Presentation and Treatment Outcome

Major depression in older adults, or late-life depression (LLD), is a common and debilitating psychiatric disorder that increases the risk of morbidity and mortality. Although the effects of LLD make it important to achieve a diagnosis and start treatment quickly, individuals with LLD are often inadequately or unsuccessfully treated. The latest treatment developments suggest that interventions targeting executive dysfunction and neuroticism, constructs associated with poor response to antidepressants in older adults, are successful in treating LLD. Specific behavioral interventions (computerized cognitive training, mindfulness meditation, aerobic exercise) appear to decrease depressive symptoms and ameliorate executive dysfunction and neuroticism, but we do not fully understand the mechanisms by which these treatments work. We review recent research on neural network changes underlying executive dysfunction and neuroticism in LLD and their association with clinical outcomes (e.g., treatment response, cognitive functioning).

Psychosocial characteristics as potential predictors of suicide in adults: an overview of the evidence with new results from prospective cohort studies

In this narrative overview of the evidence linking psychosocial factors with future suicide risk, we collected results from published reports of prospective studies with verified suicide events (mortality or, less commonly, hospitalisation) alongside analyses of new data. There is abundant evidence indicating that low socioeconomic position, irrespective of the economic status of the country in question, is associated with an increased risk of suicide, including the suggestion that the recent global economic recession has been responsible for an increase in suicide deaths and, by proxy, attempts. Social isolation, low scores on tests of intelligence, serious mental illness (both particularly strongly), chronic psychological distress, and lower physical stature (a marker of childhood exposures) were also consistently related to elevated suicide rates. Although there is some circumstantial evidence for psychosocial stress, personality disposition, and early-life characteristics such as bullying being risk indices for suicide, the general paucity of studies means it is not currently possible to draw clear conclusions about their role. Most suicide intervention strategies have traditionally not explored the modification of psychosocial factors, partly because evidence linking psychosocial factors with suicide risk is, as shown herein, largely in its infancy, or, where is does exist, for instance for intelligence and personality disposition, the characteristics in question do not appear to be easily malleable.

Treatment resistant depression: A multi-scale, systems biology approach

An estimated 50% of depressed patients are inadequately treated by available interventions. Even with an eventual recovery, many patients require a trial and error approach, as there are no reliable guidelines to match patients to optimal treatments and many patients develop treatment resistance over time. This situation derives from the heterogeneity of depression and the lack of biomarkers for stratification by distinct depression subtypes. There is thus a dire need for novel therapies. To address these known challenges, we propose a multi-scale framework for fundamental research on depression, aimed at identifying the brain circuits that are dysfunctional in several animal models of depression as well the changes in gene expression that are associated with these models. When combined with human genetic and imaging studies, our preclinical studies are starting to identify candidate circuits and molecules that are altered both in models of disease and in patient populations. Targeting these circuits and mechanisms can lead to novel generations of antidepressants tailored to specific patient populations with distinctive types of molecular and circuit dysfunction.

Influence of trait anxiety, child maltreatment, and adulthood life events on depressive symptoms

BACKGROUND

Various personality traits mediate the association between childhood stress and depressive symptoms in adulthood. The aim of this study was to clarify the indirect effects of the experience of child maltreatment on depressive symptoms and appraisal of life events in adulthood through trait anxiety.

SUBJECTS AND METHODS

A total of 404 participants who were volunteer subjects from the community were studied using the following self-administered questionnaire surveys: Patient Health Questionnaire-9, which measures depressive symptoms; State-Trait Anxiety Inventory Form Y, which measures trait anxiety; the Child Abuse and Trauma Scale, which measures child maltreatment; and Life Experiences Survey, which measures negative and positive appraisal of adulthood life events.

RESULTS

Structural equation modeling demonstrated that the experience of child maltreatment increased depressive symptoms in adulthood as well as the negative appraisal of life events in adulthood through an increase in trait anxiety. Furthermore, trait anxiety affected depressive symptoms in adulthood through its influence on the negative appraisal of adulthood life events. The following indirect effect was also significant: the experience of child maltreatment increased the negative appraisal of adulthood life events via trait anxiety and subsequently influenced adult depressive symptoms.

LIMITATIONS

The subjects of this study are volunteer subjects from the community including healthy people, and hence the results may not be generalizable to major depressive patients. Recall bias should be considered when interpreting the results. Because this study is a cross-sectional study, the causality between the experience of child maltreatment and depression is not clear.

CONCLUSION

This study suggests that trait anxiety may play a mediating role in the influence of the experience of child maltreatment on depressive symptoms in adulthood and negative appraisal of adulthood life events.

Clinical Characteristics, Life Adversities and Personality Traits in Monozygotic Twins With, at Risk of and Without Affective Disorders

Background: Affective disorders have a long-term impact on psychiatric health and are caused by multiple interacting factors including familial risk, childhood adversity, life events and personality traits. Methods: In this study, monozygotic twins (MZ) at familial risk (indexed by affective disorder in their co-twin; high-risk group), affected MZ twins (indexed by a diagnosis with affective disorder) and MZ twins with no family history of affective disorder (low-risk group) were identified through cross-linking of nation-wide Danish registers. In total, 204 MZ twins were included and psychopathology, personality traits and life adversity were evaluated by semi-structured interviews and questionnaires. Results: Affected MZ twins presented with more subclinical affective symptoms and were functionally impaired as evidenced by higher unemployment rates and reduced functional status. The affected and the high-risk groups reported more childhood adversity and had experienced more stressful life events than the low-risk group. A direct comparison within the discordant twin pairs showed that the high-risk twins presented fewer affective symptoms, better functional status, more extraversion and lower neuroticism scores than their affected co-twins although they had equal levels of life adversity as their affected co-twins. Conclusion: These findings add to the evidence indicating that patients experience higher neuroticism, persistent subclinical symptoms and reduced socio-occupational function after affective episodes. Additionally, neuroticism and extraversion seem capable of moderating the sensitivity to exposure from the environment.

The Evolutionary Life History Model of Externalizing Personality: Bridging Human and Animal Personality Science to Connect Ultimate and Proximate Mechanisms Underlying Aggressive Dominance, Hostility, and Impulsive Sensation Seeking

The present work proposes an evolutionary model of externalizing personality that defines variation in this broad psychobiological phenotype resulting from genetic influences and a conditional adaptation to high-risk environments with high extrinsic morbidity-mortality. Due to shared selection pressure, externalizing personality is coadapted to fast life history strategies and maximizes inclusive fitness under adverse environmental conditions by governing the major trade-offs between reproductive versus somatic functions, current versus future reproduction, and mating versus parenting efforts. According to this model, externalizing personality is a regulatory device at the interface between the individual and its environment that is mediated by 2 overlapping psychobiological systems, that is, the attachment and the stress-response system. The attachment system coordinates interpersonal behavior and intimacy in close relationships and the stress-response system regulates the responsivity to environmental challenge and both physiological and behavioral reactions to stress. These proximate mechanisms allow for the integration of neuroendocrinological processes underlying interindividual differences in externalizing personality. Hereinafter I further discuss the model's major implications for personality psychology, psychiatry, and public health policy.

Stress and Sleep: Results from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study

Hispanics/Latinos face specific sociocultural stressors associated with their marginalized status in the United States. While stress is known to cause poor sleep, the differential effects of the specific stressors faced by Hispanics/Latinos have not been evaluated. Using cross-sectional data from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study, we conducted weighted generalized linear models to evaluate the associations of acculturation stress, ethnic discrimination, and chronic moderate/severe stress with self-reported sleep outcomes (insomnia symptoms, daytime sleepiness, sleep duration) in individual and aggregate models adjusted for site, socio-demographics, behavioral, and medical conditions. Participants included 5313 Hispanic/Latino adults; 43.5% ≥ age 45, 54.8% female, and 22.0% US-born. Chronic moderate/severe stress, ethnic discrimination, and acculturation stress were each positively associated with sleep. In the adjusted aggregate model, only chronic moderate/severe stress was associated with insomnia symptoms (exp(b) = 1.07 for each additional stressor, 95% CI = 1.05, 1.09). Both acculturation stress (exp(b) = 1.05 for each additional SD, 95% CI = 1.02, 1.10) and ethnic discrimination (exp(b) = 1.05 for each additional SD, 95% CI = 1.01, 1.08) were associated with daytime sleepiness. Each SD increase in ethnic discrimination related to a 16% and 13% increased prevalence of short (< 7 h) (RRR = 1.16, 95% CI = 1.02, 1.31) and long sleep duration (> 9 h) (RRR = 1.13, 95% CI = 1.00, 1.27), respectively. These associations were consistent across sex. Acculturation stress and ethnic discrimination are associated with poor sleep in Hispanics/Latinos. Future research should explore whether behavioral sleep interventions minimize the impact of sociocultural stressors on sleep.

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Latina/os face unique stressors associated with their marginalized status in the USA.

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We explored the association of sociocultural stressors with Latina/o sleep.

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Acculturation stress and ethnic discrimination were associated with daytime sleepiness.

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Only chronic psychosocial stress was associated with insomnia symptoms.

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Ethnic discrimination was associated with both short and long sleep duration.

Modeling prior information of common genetic variants improves gene discovery for neuroticism

Neuroticism reflects emotional instability, and is related to various mental and physical health issues. However, the majority of genetic variants associated with neuroticism remain unclear. Inconsistent genetic variants identified by different genome-wide association studies (GWAS) may be attributable to low statistical power. We proposed a novel framework to improve the power for gene discovery by incorporating prior information of single nucleotide polymorphisms (SNPs) and combining two relevant existing tools, relative enrichment score (RES) and conditional false discovery rate (FDR). Here, SNP's conditional FDR was estimated given its RES based on SNP prior information including linkage disequilibrium (LD)-weighted genic annotation scores, total LD scores and heterozygosity. A known significant locus in chromosome 8p was excluded before estimating FDR due to long-range LD structure. Only one significant LD-independent SNP was detected by analyses of unconditional FDR and traditional GWAS in the discovery sample (N = 59 225), and notably four additional SNPs by conditional FDR. Three of the five SNPs, all identified by conditional FDR, were replicated (P < 0.05) in an independent sample (N = 170 911). These three SNPs are located in intronic regions of CADM2, LINGO2 and EP300 which have been reported to be associated with autism, Parkinson's disease and schizophrenia, respectively. Our approach using a combination of RES and conditional FDR improved power of traditional GWAS for gene discovery providing a useful framework for the analysis of GWAS summary statistics by utilizing SNP prior information, and helping to elucidate the links between neuroticism and complex diseases from a genetic perspective.

Sex differences in neural responses to subliminal sad and happy faces in healthy individuals: Implications for depression

Twice as many women as men suffer from mood and anxiety disorders, yet the biological underpinnings of this phenomenon have been understudied and remain unclear. We and others have shown that the hemodynamic response to subliminally presented sad or happy faces during functional MRI (fMRI) is a robust biomarker for the attentional bias toward negative information classically observed in major depression. Here we used fMRI to compare the performance of healthy females (n = 28) and healthy males (n = 28) on a backward masking task using a fast event-related design with gradient-recalled, echoplanar imaging with sensitivity encoding. The image data were compared across groups using a region-of-interest analysis with small-volume correction to control for multiple testing (P_corrected  < 0.05, cluster size ≥ 20 voxels). Notably, compared with males, females showed greater BOLD activity in the subgenual anterior cingulate cortex (sgACC) and the right hippocampus when viewing masked sad vs. masked happy faces. Furthermore, females displayed reduced BOLD activity in the right pregenual ACC and left amygdala when viewing masked happy vs. masked neutral faces. Given that we have previously reported similar findings for depressed participants compared with healthy controls (regardless of gender), our results raise the possibility that on average healthy females show subtle emotional processing biases that conceivably reflect a subgroup of women predisposed to depression. Nevertheless, we note that the differences between males and females were small and derived from region-of-interest rather than voxelwise analyses. © 2016 Wiley Periodicals, Inc.

The importance of personality and life-events in anxious depression: from trait to state anxiety

OBJECTIVES

Anxious depression is associated with severe impairment and bad prognoses. We hypothesize that recent life-events are associated with more anxiety in late-life depression and that this is conditional upon the level of certain personality traits.

METHOD

Baseline data of the Netherlands Study of Depression in Older Persons (NESDO) were used. In 333 patients (≥60 years) suffering from a major depressive disorder, anxiety was assessed with the BAI, personality traits with the NEO-FFI and the Mastery Scale, and life-events with the Brugha questionnaire. Multiple linear regression analyses were applied with anxiety severity as dependent and life-events and personality traits as independent variables.

RESULTS

147 patients (44.1%) had recently experienced one or more life-events. The presence of a life-event is not associated with anxiety (p = .161) or depression severity (p = .440). However, certain personality traits interacted with life-events in explaining anxiety severity. Stratified analyses showed that life-events were associated with higher anxiety levels in case of high levels of neuroticism and openness and low levels of conscientiousness or mastery.

CONCLUSIONS

In the face of a life-event, personality traits may play a central role in increased anxiety levels in late-life depression.

Partially distinct combinations of psychological, metabolic and inflammatory risk factors are prospectively associated with the onset of the subtypes of Major Depressive Disorder in midlife

BACKGROUND

Given the well known heterogeneity of Major Depressive Disorder (MDD), dividing this complex disorder into subtypes is likely to be a more promising approach to identify its determinants than to study it as a whole.

METHODS

In a prospective population-based cohort study (CoLaus|PsyCoLaus) with 5.5 years of follow-up, 1524 participants without MDD at baseline, aged 35-66 years (mean age 51.4 years, 43.4% females), participated in the physical and psychiatric baseline and the psychiatric follow-up evaluations.

RESULTS

The incidence of both atypical and melancholic MDD during the follow-up period were predicted by female sex, a lifetime history of minor depressive disorders and higher neuroticism scores. Higher baseline body mass index was associated with the onset of atypical MDD, whereas the absence of hypertension and younger age were associated with the development of melancholic MDD. Unspecified MDD was predicted by younger age, low concentrations of tumor necrosis factor-α and elevated life-event impact scores.

LIMITATIONS

The age range of our cohort restricts the identification of risk factors to MDD with onset in midlife and the recruitment in an urban area limits the generalizability of the findings.

CONCLUSIONS

Our data suggest that MDD subtypes are predicted by partially distinct combinations of baseline characteristics suggesting that these subtypes not only differ in their clinical manifestations but also in factors that contribute to their development. Subjects with minor depressive episodes, especially in combination with particular personality features, deserve close clinical attention to prevent the subsequent onset of atypical and melancholic major depression.

A Daily Diary Investigation of the Influence of Early Family Adversity on Social Functioning during the Transition to Adulthood

Early life stressors are associated with maladaptive social functioning in childhood and adolescence, but it is unclear whether and how the negative interpersonal effects of stress persist into adulthood. Daily diary surveys were used to examine young adults' social behavior and mood reactivity to social stressors as a function of experiences of early family adversity. Stressful early family environments predicted more daily reassurance seeking, but not aggression, withdrawal, or positive social behavior. Early family adversity also moderated the within-person effects of social stressors on next-day mood, such that individuals with high levels of adversity had elevated next-day negative affect in response to higher than average social stress. Findings highlight the enduring impact of early adversity on social development, with implications for developing targeted policies and interventions.

Neural basis of individual differences in the response to mental stress: a magnetoencephalography study

Stress is a risk factor for the onset of mental disorders. Although stress response varies across individuals, the mechanism of individual differences remains unclear. Here, we investigated the neural basis of individual differences in response to mental stress using magnetoencephalography (MEG). Twenty healthy male volunteers completed the Temperament and Character Inventory (TCI). The experiment included two types of tasks: a non-stress-inducing task and a stress-inducing task. During these tasks, participants passively viewed non-stress-inducing images and stress-inducing images, respectively, and MEG was recorded. Before and after each task, MEG and electrocardiography were recorded and subjective ratings were obtained. We grouped participants according to Novelty seeking (NS) - tendency to be exploratory, and Harm avoidance (HA) - tendency to be cautious. Participants with high NS and low HA (n = 10) assessed by TCI had a different neural response to stress than those with low NS and high HA (n = 10). Event-related desynchronization (ERD) in the beta frequency band was observed only in participants with high NS and low HA in the brain region extending from Brodmann's area 31 (including the posterior cingulate cortex and precuneus) from 200 to 350 ms after the onset of picture presentation in the stress-inducing task. Individual variation in personality traits (NS and HA) was associated with the neural response to mental stress. These findings increase our understanding of the psychological and neural basis of individual differences in the stress response, and will contribute to development of the psychotherapeutic approaches to stress-related disorders.

Neuroticism-related personality traits are associated with posttraumatic stress after abortion: findings from a Swedish multi-center cohort study

Background

Most women who choose to terminate a pregnancy cope well following an abortion, although some women experience severe psychological distress. The general interpretation in the field is that the most consistent predictor of mental disorders after induced abortion is the mental health issues that women present with prior to the abortion. We have previously demonstrated that few women develop posttraumatic stress disorder (PTSD) or posttraumatic stress symptoms (PTSS) after induced abortion. Neuroticism is one predictor of importance for PTSD, and may thus be relevant as a risk factor for the development of PTSD or PTSS after abortion. We therefore compared Neuroticism-related personality trait scores of women who developed PTSD or PTSS after abortion to those of women with no evidence of PTSD or PTSS before or after the abortion.

Methods

A Swedish multi-center cohort study including six Obstetrics and Gynecology Departments, where 1294 abortion-seeking women were included. The Screen Questionnaire-Posttraumatic Stress Disorder (SQ-PTSD) was used to evaluate PTSD and PTSS. Measurements were made at the first visit and at three and six month after the abortion. The Swedish universities Scales of Personality (SSP) was used for assessment of Neuroticism-related personality traits. Multiple logistic regression analyses were performed to investigate the risk factors for development of PTSD or PTSS post abortion.

Results

Women who developed PTSD or PTSS after the abortion had higher scores than the comparison group on several of the personality traits associated with Neuroticism, specifically Somatic Trait Anxiety, Psychic Trait Anxiety, Stress Susceptibility and Embitterment. Women who reported high, or very high, scores on Neuroticism had adjusted odds ratios for PTSD/PTSS development of 2.6 (CI 95% 1.2–5.6) and 2.9 (CI 95% 1.3–6.6), respectively.

Conclusion

High scores on Neuroticism-related personality traits influence the risk of PTSD or PTSS post abortion. This finding supports the argument that the most consistent predictor of mental disorders after abortion is pre-existing mental health status.

Negative Affectivity, Aging, and Depression: Results From the Neurobiology of Late-Life Depression (NBOLD) Study

OBJECTIVE

Neuroticism is a common yet understudied condition in older adults. We hypothesized that presence of high negativity affectivity (NA), a key feature of neuroticism, would be associated with different prefrontal cortex (PFC) activity and connectivity patterns in depressed and never-depressed older adults.

METHODS

This is a baseline cross-sectional analysis of a cohort study of 52 depressed and 36 never-depressed older adults. Assessments included NA scores from the Type D Scale-14 and Montgomery-Åsberg Depression Rating Scale scores. All subjects had a 3T brain functional magnetic resonance imaging resting scan, neuronal activity determined by amplitude of low-frequency fluctuations (ALFFs) were obtained, and resting state functional connectivity (FC) analyses were performed. Analyses of covariance were conducted on ALFFs and FC to examine significant differences between groups.

RESULTS

In the ALFF analyses there were clearly different patterns between depressed and comparison groups in the correlation of ALFFs and NA. The correlation differences between the two groups were significant in the dorsomedial PFC, insula, amygdala, and posterior cingulate cortex (PCC). FC analyses revealed different between-group connectivity patterns. Significantly higher ventromedial PFC-amygdala FC with NA correlation was found in the depressed group than that in the never-depressed group.

CONCLUSION

This study confirms differential activity of the dorsal and ventral regions of the medial PFC in individuals with high neuroticism. Our findings suggest increased rostral medial PFC activity may be a marker of resilience to depression in the elderly and decreased anterior ventromedial PFC, PCC, and amygdala activity may be a result of successful emotion regulation in never-depressed higher NA individuals.

The cortisol:C-reactive protein ratio and negative affect reactivity in depressed adults

OBJECTIVE

We evaluated the effect of the cortisol (CORT) to high sensitivity C-reactive protein (hsCRP) ratio on stress-induced negative affect (NA) reactivity and whether the association was moderated by depressive symptom severity and gender. The CORT/CRP ratio was used to evaluate the integrity of the negative feedback loop between the hypothalamic-pituitary-adrenal axis and inflammatory response system.

METHOD

Basal CORT and hsCRP levels were measured in fasting blood samples from 198 medication-free and nonsmoking healthy men and women. Depressive symptom severity was assessed using the Hamilton Rating Scale for Depression (HAMD). NA ratings were collected at baseline and at the completion of the laboratory stressors, the Anger Recall Interview (ARI) and reading.

RESULTS

Adjusting for potential confounders and baseline NA, analysis revealed a significant relationship between CORT/CRP ratio and NA reactivity to ARI as a function of depressive symptom severity. Simple effects revealed that for participants with high HAMD, decreasing CORT/CRP ratio, suggestive of an insufficient CORT release relative to higher hsCRP, predicted increasing stress-induced NA reactivity. For participants with low HAMD, the CORT/CRP ratio failed to predict NA reactivity. Gender did not moderate the joint effect of depressive symptom severity and the CORT/CRP ratio on stress-induced NA reactivity.

CONCLUSIONS

This is the first study to document that a premorbid dysregulation of the neuro-immune relationship, characterized by an insufficient release of CORT in conjunction with higher CRP, plays a role in stress sensitivity, and specifically NA reactivity, in individuals with elevated levels of depression symptoms. (PsycINFO Database Record

Interactions between the vascular endothelial growth factor gene polymorphism and life events in susceptibility to major depressive disorder in a Chinese population

BACKGROUND

Recent studies suggest that vascular endothelial growth factor (VEGF) is involved in the development of major depressive disorder. The aim of this study is to investigate the interaction between vascular endothelial growth factor (VEGF) polymorphism (+405G/C, rs2010963) and negative life events in the pathogenesis of major depressive disorder (MDD).

METHODS

DNA genotyping was performed on peripheral blood leukocytes in 274 patients with MDD and 273 age-and sex-matched controls. The frequency and severity of negative life events were assessed by the Life Events Scale (LES). A logistics method was employed to assess the gene-environment interaction (G×E).

RESULTS

Differences in rs2010963 genotype distributions were observed between MDD patients and controls. Significant G×E interactions between allelic variation of rs2010963 and negative life events were observed. Individuals carrying the C alleles were susceptible to MDD only when exposed to high-negative life events.

CONCLUSIONS

These results indicate that interactions between the VEGF rs2010963 polymorphism and environment increases the risk of developing MDD.

The influence of parental care and overprotection, neuroticism and adult stressful life events on depressive symptoms in the general adult population

BACKGROUND

The quality of parenting, neuroticism, and adult stressful life events are reportedly associated with depressive symptoms. However, previous studies have not examined the complex interaction between these three factors. In this study, we hypothesized that the quality of parenting (care and overprotection) acts on depressive symptoms through 'neuroticism' and the appraisal of adult stressful life events, and this hypothesis was verified by structural equation modeling.

METHODS

Four hundred one participants from the general adult population were studied using the following self-administered questionnaire surveys: Patient Health Questionnaire-9 (PHQ-9), Parental Bonding Instrument (PBI), neuroticism subscale of the short version of the Eysenck Personality Questionnaire-revised (EPQ-R), and Life Experiences Survey (LES). The data were analyzed with single and multiple regression analyses and covariance structure analyses.

RESULTS

In the covariance structure analysis, neuroticism scores and negative change scores on the LES acted on the depressive symptoms (PHQ-9 scores) directly, but care or overprotection in childhood on the PBI did not act on them directly. Low care and high overprotection of the PBI increased depressive symptoms and negative change scores on the LES through enhanced neuroticism, which is regarded as a mediator in these effects.

LIMITATIONS

The subjects of this study were nonclinical volunteers; the findings might not be generalizable to psychiatric patients.

CONCLUSIONS

This research showed that low care and high overprotection of maternal and paternal parenting in childhood influence depressive symptoms indirectly through enhanced neuroticism in general adults. These findings suggest that neuroticism mediates the long-term effect of the quality of parenting on depression in adulthood.

Gene by cognition interaction on stress-induced attention bias for food: Effects of 5-HTTLPR and ruminative thinking

INTRODUCTION

Stress is often found to increase the preference and intake of high caloric foods. This effect is known as emotional eating and is influenced by cognitive as well as biological stress vulnerabilities. An S-allele of the 5-HTTLPR gene has been linked to decreased (brain) serotonin efficiency, leading to decreased stress resilience and increased risks for negative affect and eating related disturbances. Recently it has been proposed that a cognitive ruminative thinking style can further exacerbate the effect of this gene by prolonging the already increased stress response, thereby potentially increasing the risk of compensating by overeating high palatable foods.

OBJECTIVE

This study was aimed at investigating whether there is an increased risk for emotional eating in high ruminative S/S-allele carriers reflected by an increased attention bias for high caloric foods during stress.

METHODS

From a large (N=827) DNA database, participants (N=100) were selected based on genotype (S/S or L/L) and ruminative thinking style and performed an eye-tracking visual food-picture probe task before and after acute stress exposure. A significant Genotype x Rumination x Stress-interaction was found on attention bias for savory food; indicating that a stress-induced attention bias for specifically high-caloric foods is moderated by a gene x cognitive risk factor.

CONCLUSION

Both a genetic (5-HTTLPR) and cognitive (ruminative thinking) stress vulnerability may mutually increase the risk for stress-related abnormal eating patterns.

Subcortical volume and white matter integrity abnormalities in major depressive disorder: findings from UK Biobank imaging data

Previous reports of altered grey and white matter structure in Major Depressive Disorder (MDD) have been inconsistent. Recent meta-analyses have, however, reported reduced hippocampal grey matter volume in MDD and reduced white matter integrity in several brain regions. The use of different diagnostic criteria, scanners and imaging sequences may, however, obscure further anatomical differences. In this study, we tested for differences in subcortical grey matter volume (n = 1157) and white matter integrity (n = 1089) between depressed individuals and controls in the subset of 8590 UK Biobank Imaging study participants who had undergone depression assessments. Whilst we found no significant differences in subcortical volumes, significant reductions were found in depressed individuals versus controls in global white matter integrity, as measured by fractional anisotropy (FA) (β = −0.182, p = 0.005). We also found reductions in FA in association/commissural fibres (β = −0.184, p_corrected = 0.010) and thalamic radiations (β = −0.159, p_corrected = 0.020). Tract-specific FA reductions were also found in the left superior longitudinal fasciculus (β = −0.194, p_corrected = 0.025), superior thalamic radiation (β = −0.224, p_corrected = 0.009) and forceps major (β = −0.193, p_corrected = 0.025) in depression (all betas standardised). Our findings provide further evidence for disrupted white matter integrity in MDD.

Who pays the price for high neuroticism? Moderators of longitudinal risks for depression and anxiety

BACKGROUND

High neuroticism is a well-established risk for present and future depression and anxiety, as well as an emerging target for treatment and prevention. The current analyses tested the hypothesis that physical, social and socio-economic disadvantages each amplify risks from high neuroticism for longitudinal increases in depression and anxiety symptoms.

METHOD

A national sample of adults (n = 7108) provided structured interview and questionnaire data in the Midlife Development in the United States Survey. Subsamples were reassessed roughly 9 and 18 years later. Time-lagged multilevel models predicted changes in depression and anxiety symptom intensity across survey waves.

RESULTS

High neuroticism predicted increases in a depression/anxiety symptom composite across retest intervals. Three disadvantage dimensions - physical limitations (e.g. chronic illness, impaired functioning), social problems (e.g. less social support, more social strain) and low socio-economic status (e.g. less education, lower income) - each moderated risks from high neuroticism for increases in depression and anxiety symptoms. Collectively, high scores on the three disadvantage dimensions amplified symptom increases attributable to high neuroticism by 0.67 standard deviations. In contrast, neuroticism was not a significant risk for increases in symptoms among participants with few physical limitations, few social problems or high socio-economic status.

CONCLUSIONS

Risks from high neuroticism are not shared equally among adults in the USA. Interventions preventing or treating depression or anxiety via neuroticism could be targeted toward vulnerable subpopulations with physical, social or socio-economic disadvantages. Moreover, decreasing these disadvantages may reduce mental health risks from neuroticism.

Childhood trauma and negative memory bias as shared risk factors for psychopathology and comorbidity in a naturalistic psychiatric patient sample

BACKGROUND

Both childhood trauma and negative memory bias are associated with the onset and severity level of several psychiatric disorders, such as depression and anxiety disorders. Studies on these risk factors, however, generally use homogeneous noncomorbid samples. Hence, studies in naturalistic psychiatric samples are lacking. Moreover, we know little about the quantitative relationship between the frequency of traumatic childhood events, strength of memory bias and number of comorbid psychiatric disorders; the latter being an index of severity. The current study examined the association of childhood trauma and negative memory bias with psychopathology in a large naturalistic psychiatric patient sample.

METHODS

Frequency of traumatic childhood events (emotional neglect, psychological-, physical- and sexual abuse) was assessed using a questionnaire in a sample of 252 adult psychiatric patients with no psychotic or bipolar-I disorder and no cognitive disorder as main diagnosis. Patients were diagnosed for DSM-IV Axis-I and Axis-II disorders using a structured clinical interview. This allowed for the assessment of comorbidity between disorders. Negative memory bias for verbal stimuli was measured using a computer task.

RESULTS

Linear regression models revealed that the frequency of childhood trauma as well as negative memory bias was positively associated with psychiatric comorbidity, separately and above and beyond each other (all p < .01).

CONCLUSIONS

The results indicate that childhood trauma and negative memory bias may be of importance for a broader spectrum of psychiatric diagnoses, besides the frequently studied affective disorders. Importantly, frequently experiencing traumatic events during childhood increases the risk of comorbid psychiatric disorders.

Incremental validity of the PID-5 in relation to the five factor model and traditional polythetic personality criteria of the DSM-5

BACKGROUND

This study assessed the incremental validity of the Personality Inventory for DSM-5 (PID-5) beyond the impact of demographic, burden of illness, five-factor model of personality, and DSM-5 personality disorder criteria with respect to associations with admission psychiatric symptoms and functional disability.

METHODS

Psychiatric inpatients (N = 927) were administered the Big Five Inventory, PID-5, and personality disorder criteria counts. Prior treatment utilization, as well as baseline depression, anxiety, emotion regulation, and functional disability were administered within two days of the personality measures. Hierarchical regression models were used to explore the association of personality functioning with symptom functioning, emotion regulation and disability.

RESULTS

Neuroticism was associated with all symptom measures, providing further support for its relevance in clinical populations. Personality trait domains (negative affect, detachment, and psychoticism) from the PID-5 demonstrated incremental validity in predicting baseline symptom and disability functioning over and above demographic, burden of illness, and psychiatric comorbidity and five-factor model (FFM) personality traits.

CONCLUSIONS

Dimensional measures of personality functioning were consistently associated with baseline symptom functioning, supporting the relevance of personality functioning as it relates to psychiatric symptoms. The PID-5 uniquely contributed to the prediction of baseline symptom functioning, thus providing incremental validity over gold-standard personality trait measures.

The impact of induced anxiety on affective response inhibition

Studying the effects of experimentally induced anxiety in healthy volunteers may increase our understanding of the mechanisms underpinning anxiety disorders. Experimentally induced stress (via threat of unpredictable shock) improves accuracy at withholding a response on the sustained attention to response task (SART), and in separate studies improves accuracy to classify fearful faces, creating an affective bias. Integrating these findings, participants at two public science engagement events (n = 46, n = 55) were recruited to explore the effects of experimentally induced stress on an affective version of the SART. We hypothesized that we would see an improved accuracy at withholding a response to affectively congruent stimuli (i.e. increased accuracy at withholding a response to fearful 'no-go' distractors) under threat of shock. Induced anxiety slowed reaction time, and at the second event quicker responses were made to fearful stimuli. However, we did not observe improved inhibition overall during induced anxiety, and there was no evidence to suggest an interaction between induced anxiety and stimulus valence on response accuracy. Indeed Bayesian analysis provided decisive evidence against this hypothesis. We suggest that the presence of emotional stimuli might make the safe condition more anxiogenic, reducing the differential between conditions and knocking out any threat-potentiated improvement.

Exploring the feasibility and usability of the experience sampling method to examine the daily lives of patients with acquired brain injury

The experience sampling method (ESM) is a structured diary method with high ecological validity, in that it accurately captures the everyday context of individuals through repeated measurements in naturalistic environments. Our main objective was to investigate the feasibility of using ESM in individuals with acquired brain injury (ABI). A second goal was to explore the usability of ESM data on a clinical level, by illustrating the interactions between person, environment, and affect. The PsyMate device provided ABI patients (N = 17) with ten signals (beeps) per day during six consecutive days. Each beep was followed by a digital questionnaire assessing mood, location, activities, social context, and physical well-being. Results demonstrated high feasibility with a 71% response rate and a 99% completion rate of the questionnaires. There were no dropouts and the method was experienced as user-friendly. Time-lagged multilevel analysis showed that higher levels of physical activity and fatigue predicted higher levels of negative affect at the same point in time, but not at later time points. This study illustrates the potential of ESM to identify complex person-environment dynamics after ABI, while generating understandable and easy to use graphical feedback.

Thought Control Ability Is Different from Rumination in Explaining the Association between Neuroticism and Depression: A Three-Study Replication

Neuroticism is the most common vulnerability factor of depression. However, the mechanism underlying this vulnerability is still unclear. Previous studies suggested that rumination intensifies the negative effect of neuroticism on depression. However, whether cognitive control could explain the association between neuroticism and depression remains unclear to date. Therefore, this study evaluated the indirect effects of rumination and thought control on the relationship between neuroticism and depression. Seven self-report measures were employed among healthy and main depression disorder (MDD) participants. Three studies were used to examine the hypotheses. Results of the three studies showed significant correlations among neuroticism, rumination, thought control, and depression. Rumination mediated the link between neuroticism and depression among healthy young adults, and this finding replicated previous studies. This study provided new evidence that thought control mediates the association between neuroticism and depression in both healthy and MDD populations. In conclusion, rumination increases neuroticism risk for depression, but high-level thought control decreases the effect of neuroticism on depression. This study may serve as a reference to develop effective and focused interventions for MDD patients.

How Does Psychosocial Behavior Contribute to Cognitive Health in Old Age?

With the aging of the U.S. population, the number of cognitively disabled persons is expected to substantially increase in coming decades, underscoring the urgent need for effective interventions. Here, we review the current evidence linking psychosocial factors to late-life cognitive loss and consider the study design needed to illuminate the biologic bases of the associations. We then examine an ongoing study that includes several of the key design elements, the Rush Memory and Aging Project. In this longitudinal clinical-pathological cohort study, indicators of personality, social connectedness, and psychological well-being were shown to predict late-life cognitive outcomes. Participants who died underwent a uniform neuropathologic examination to quantify common dementia-related pathologies. Some psychosocial indicators were associated with cerebral infarction; some indicators modified the association of neurodegenerative pathologies with cognitive loss; and the association of some indicators with cognitive outcomes appears to be independent of the pathologies traditionally associated with late-life dementia. These findings suggest that psychosocial behavior influences late-life cognitive health through multiple neurobiologic mechanisms. A better understanding of these mechanisms may lead to novel strategies for preserving cognitive health in old age.

Gender, Life Events, and Depression: An Exploratory Study

CONTEXT

Literature is inconsistent about the role of gender in mediating the relationship between life events and depression.

AIM

Our objective was to explore gender differences in patterns and frequencies of stressful life events before onset of a depressive episode.

SETTING AND DESIGN

Cross-sectional study at a tertiary care center.

SUBJECTS AND METHODS

One hundred patients fulfilling Diagnostic and Statistical Manual of Mental Disorders fourth edition criteria for current major depression (50 males and 50 females) were recruited for the study. Structured instruments were used to assess psychiatric comorbidity, episode severity, and stressful life events. We compared the number and frequency of stressful life events between genders and their relationship with demographic and clinical variables.

STATISTICAL ANALYSIS USED

Mann-Whitney U-test and Chi-square test.

RESULTS

Women with depression were older, more likely to be married (P < 0.01), had lower rates of comorbid panic disorder (P < 0.01) and nicotine dependence (P = 0.016) compared to men. Total stress scores and median number of stressful events in the year before onset of depression were significantly lower in women (P < 0.01). Getting married, job or property-related stressors, and breakup of friendship were more commonly reported stressors among males while more females reported dowry-related issues before symptom onset. In stratified analysis, these gender differences continued to hold good only in those with comorbid dysthymia.

CONCLUSION

There appears to be a sex-specific effect of certain life events on depression. Comorbid dysthymia may play an important role in mediating this differential stress sensitivity across genders.

How do antidepressants work? New perspectives for refining future treatment approaches

Most currently available antidepressants target monoamine neurotransmitter function. However, a purely neurotransmitter-based explanation for antidepressant drug action is challenged by the delayed clinical onset of most agents and the need to explain how neurochemical changes reverse the many different symptoms of depression. Novel approaches to understanding of antidepressant drug action include a focus on early changes in emotional and social processing and the role of neural plasticity. In this Review, we discuss the ways in which these two different theories reflect different or complementary approaches, and how they might be integrated to offer novel solutions for people with depression. We consider the predictions made by these mechanistic approaches for the stratification and development of new therapeutics for depression, and the next steps that need to be made to facilitate this translation of science to the clinic.

The interaction of miR-34b/c polymorphisms and negative life events increases susceptibility to major depressive disorder in Han Chinese population

BACKGROUND

Previous studies have shown that microRNAs(miRNAs) are involved in the pathogenesis of MDD; in particular, miR-34b/c has been implicated in MDD risk and found to exert antidepressant effects. However, the effects of miR-34b/c polymorphisms on MDD risk have not been investigated.

METHODS

In this study, we evaluated the effect of miR-34b/c gene polymorphisms and their interaction with negative life events in relation to MDD, using data from 381 Han Chinese patients with MDD and 291 healthy volunteers. Allelic, genotypic, haplotypic, and gene-environment associations were analyzed using UNPHASED and SPSS software.

RESULTS

After discarding data with extremely severe negative life events in our study population, we found an association between rs4938723, rs2187473 polymorphisms and MDD in the dominant models (TC/CC vs. TT, OR=1.45, P=0.027; TC/CC vs. TT, OR=3.32, P=0.030). In haplotype analysis, the C-G haplotype (rs4938723/rs28757623) showed the strongest association with MDD (OR=1.95, P=0.026). Additionally, we found significant gene-environment combination rs4938723 C allele, rs28757623 G allele and high level of negative life events (C-G-HN) was significantly associated with MDD (OR, 3.85; 95% CI, 1.62-9.13). In addition, the combination of (C-C-HN) is of significance (OR, 2.99; 95% CI, 1.36-6.60), indicating that the rs28757623 C allele may contribute to the risk of MDD as well.

LIMITATIONS

The sample size was small and the role of miR-34b/c polymorphisms for MDD should be assessed using independent samples from other ethnic populations.

CONCLUSIONS

Our results suggest that miR-34b/c is a susceptibility factor for MDD stratified by negative life events and that rs4938723 is a significant association locus for gene-environment interaction in relation to MDD risk.

Exploring the role of testosterone in the cerebellum link to neuroticism: From adolescence to early adulthood

Previous research has found an association between a smaller cerebellar volume and higher levels of neuroticism. The steroid hormone testosterone reduces stress responses and the susceptibility to negative mood. Together with in vitro studies showing a positive effect of testosterone on cerebellar gray matter volumes, we set out to explore the role of testosterone in the relation between cerebellar gray matter and neuroticism. Structural magnetic resonance imaging scans were acquired, and indices of neurotic personality traits were assessed by administering the depression and anxiety scale of the revised NEO personality inventory and Gray's behavioural avoidance in one hundred and forty-nine healthy volunteers between 12 and 27 years of age. Results demonstrated an inverse relation between total brain corrected cerebellar volumes and neurotic personality traits in adolescents and young adults. In males, higher endogenous testosterone levels were associated with lower scores on neurotic personality traits and larger cerebellar gray matter volumes. No such relations were observed in the female participants. Analyses showed that testosterone significantly mediated the relation between male cerebellar gray matter and measures of neuroticism. Our findings on the interrelations between endogenous testosterone, neuroticism and cerebellar morphology provide a cerebellum-oriented framework for the susceptibility to experience negative emotions and mood in adolescence and early adulthood.

Not in one metric: Neuroticism modulates different resting state metrics within distinctive brain regions

INTRODUCTION

Neuroticism is a complex personality trait encompassing diverse aspects. Notably, high levels of neuroticism are related to the onset of psychiatric conditions, including anxiety and mood disorders. Personality traits are stable individual features; therefore, they can be expected to be associated with stable neurobiological features, including the Brain Resting State (RS) activity as measured by fMRI. Several metrics have been used to describe RS properties, yielding rather inconsistent results. This inconsistency could be due to the fact that different metrics portray different RS signal properties and that these properties may be differently affected by neuroticism. To explore the distinct effects of neuroticism, we assessed several distinct metrics portraying different RS properties within the same population.

METHOD

Neuroticism was measured in 31 healthy subjects using the Zuckerman-Kuhlman Personality Questionnaire; RS was acquired by high-resolution fMRI. Using linear regression, we examined the modulatory effects of neuroticism on RS activity, as quantified by the Amplitude of low frequency fluctuations (ALFF, fALFF), regional homogeneity (REHO), Hurst Exponent (H), global connectivity (GC) and amygdalae functional connectivity.

RESULTS

Neuroticism modulated the different metrics across a wide network of brain regions, including emotional regulatory, default mode and visual networks. Except for some similarities in key brain regions for emotional expression and regulation, neuroticism affected different metrics in different ways.

DISCUSSION

Metrics more related to the measurement of regional intrinsic brain activity (fALFF, ALFF and REHO), or that provide a parsimonious index of integrated and segregated brain activity (HE), were more broadly modulated in regions related to emotions and their regulation. Metrics related to connectivity were modulated across a wider network of areas. Overall, these results show that neuroticism affects distinct aspects of brain resting state activity. More in general, these findings indicate that a multiparametric approach may be required to obtain a more detailed characterization of the neural underpinnings of a given psychological trait.

The evolving relationship between premorbid intelligence and serious depression across the lifespan - A longitudinal study of 43,540 Swedish men

BACKGROUND

An association between higher intelligence and lower probability of serious depression has previously been established. Yet, to our knowledge, no large prospective study has examined the relationship across the lifespan.

METHODS

A cohort of 49,321 Swedish men was followed from conscription in 1969-70 (age 18-20) through to 2008. Odds ratios (OR) for first time hospitalisation for depression (FTHD) were calculated in relation to intelligence for distinct time periods across the lifespan, while controlling for established risk factors for depression.

RESULTS

There was a linear association between higher intelligence in youth and lower odds for FTHD during the entire follow-up period, 1973-2008. The association got progressively weaker across the lifespan. During 1973-80, one step down on the stanine scale was associated with an unadjusted increase in OR of 1.34 [95% confidence interval (CI) 1.26-1.42], adjusted OR 1.23 [1.15-1.32]; while, during 2001-2008, the ORs were less than half of the magnitude of the first period, unadjusted 1.14 [1.07-1.21], and adjusted 1.09 [1.01-1.17].

LIMITATIONS

The study includes men only, and the number of available places for in-patient care decreased during the follow-up period.

CONCLUSION

For the first time, we have shown that the association between lower intelligence and depression decreases over time. The attenuation of the association in the adjusted models suggests a slower accumulation of depressogenic stressors among people with a higher IQ-score. Further exploration of intelligence's role in the etiology of depression across the lifespan is required in order to facilitate adequate diagnoses and ameliorating interventions.

A Preliminary Study of the Opioid System and Personality Traits Using Positron Emission Tomography

BACKGROUND

Personality traits, such as Neuroticism and Extraversion, have been implicated in the processing of emotion. The neural correlates most often associated with Neuroticism and Extraversion are the insular cortex, orbitofrontal cortex, amygdala, and ventral striatum.

OBJECTIVE

The aim of the current study was to explore neurotransmitter systems underlying those neural correlates and investigate the relationship between personality traits and opioid receptor binding potential.

METHOD

Twelve healthy participants completed an [11C]diprenorphine positron emission tomography scan at rest. Endogenous opioid levels as indicated by opioid receptor binding potential was examined in relation to personality phenotype.

RESULTS

A high score of Neuroticism, a personality trait characterized by negative affect, was found to be associated with high opioid receptor binding in the right anterior insula. Conversely, a high score of Extraversion, a personality trait characterized by positive affect, was found to be associated with low opioid receptor binding in the left posterior insula.

CONCLUSIONS

While preliminary, the results of this study suggest that the expression of Neuroticism and Extraversion is related to baseline function of the opioid neurotransmitter system in the insular cortex. These findings may help elucidate the neural mechanisms underlying the expression of personality traits, particularly those implicated in affective processing.