Emotional (in)stability: Neuroticism is associated with increased variability in negative emotion after all.

The personality trait neuroticism is tightly linked to mental health, and neurotic people experience stronger negative emotions in everyday life. But, do their negative emotions also show greater fluctuation? This commonsensical notion was recently questioned by [Kalokerinos et al. Proc Natl Acad Sci USA 112, 15838-15843 (2020)], who suggested that the associations found in previous studies were spurious. Less neurotic people often report very low levels of negative emotion, which is usually measured with bounded rating scales. Therefore, they often pick the lowest possible response option, which severely constrains the amount of emotional variability that can be observed in principle. Applying a multistep statistical procedure that is supposed to correct for this dependency, [Kalokerinos et al. Proc Natl Acad Sci USA 112, 15838-15843 (2020)] no longer found an association between neuroticism and emotional variability. However, like other common approaches for controlling for undesirable effects due to bounded scales, this method is opaque with respect to the assumed mechanism of data generation and might not result in a successful correction. We thus suggest an alternative approach that a) takes into account that emotional states outside of the scale bounds can occur and b) models associations between neuroticism and both the mean and variability of emotion in a single step with the help of Bayesian censored location-scale models. Simulations supported this model over alternative approaches. We analyzed 13 longitudinal datasets (2,518 individuals and 11,170 measurements in total) and found clear evidence that more neurotic people experience greater variability in negative emotion.

Neuroticism/Negative Emotionality Is Associated with Increased Reactivity to Uncertain Threat in the Bed Nucleus of the Stria Terminalis, Not the Amygdala.

Neuroticism/negative emotionality (N/NE)-the tendency to experience anxiety, fear, and other negative emotions-is a fundamental dimension of temperament with profound consequences for health, wealth, and well-being. Elevated N/NE is associated with a panoply of adverse outcomes, from reduced socioeconomic attainment to psychiatric illness. Animal research suggests that N/NE reflects heightened reactivity to uncertain threat in the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (Ce), but the relevance of these discoveries to humans has remained unclear. Here we used a novel combination of psychometric, psychophysiological, and neuroimaging approaches to test this hypothesis in an ethnoracially diverse, sex-balanced sample of 220 emerging adults selectively recruited to encompass a broad spectrum of N/NE. Cross-validated robust-regression analyses demonstrated that N/NE is preferentially associated with heightened BST activation during the uncertain anticipation of a genuinely distressing threat (aversive multimodal stimulation), whereas N/NE was unrelated to BST activation during certain-threat anticipation, Ce activation during either type of threat anticipation, or BST/Ce reactivity to threat-related faces. It is often assumed that different threat paradigms are interchangeable assays of individual differences in brain function, yet this has rarely been tested. Our results revealed negligible associations between BST/Ce reactivity to the anticipation of threat and the presentation of threat-related faces, indicating that the two tasks are nonfungible. These observations provide a framework for conceptualizing emotional traits and disorders; for guiding the design and interpretation of biobank and other neuroimaging studies of psychiatric risk, disease, and treatment; and for refining mechanistic research.

The Human Centromedial Amygdala Contributes to Negative Prediction Error Signaling during Appetitive and Aversive Pavlovian Gustatory Learning.

Prediction error (PE) is the mismatch between a prior expectation and reality, and it lies at the core of associative learning about aversive and appetitive stimuli. Human studies on fear learning have linked the amygdala to aversive PEs. In contrast, the relationship between the amygdala and PE in appetitive settings and stimuli, unlike those that induce fear, has received less research attention. Animal studies show that the amygdala is a functionally heterogeneous structure. Nevertheless, the role of the amygdala nuclei in PE signaling remains unknown in humans. To clarify the role of two subdivisions of the human amygdala, the centromedial amygdala (CMA) and basolateral amygdala (BLA), in appetitive and aversive PE signaling, we used gustatory pavlovian learning involving eating-related naturalistic outcomes. Thirty-eight right-handed individuals (19 females) participated in the study. We found that surprise with neutral feedback when a reward is expected triggers activity within the left and right CMA. When an aversive outcome is expected, surprise with neutral feedback triggers activity only within the left CMA. Notably, the BLA was not activated by those conditions. Thus, the CMA engages in negative PE signaling during appetitive and aversive gustatory pavlovian learning, whereas the BLA is not critical for this process. In addition, PE-related activity within the left CMA during aversive learning is negatively correlated with neuroticism and positively correlated with extraversion. The findings indicate the importance of the CMA in gustatory learning when the value of outcomes changes and have implications for understanding psychological conditions that manifest perturbed processing of negative PEs.SIGNIFICANCE STATEMENT A discrepancy between a prediction and an actual outcome (PE) plays a crucial role in learning. Learning improves when an outcome is more significant than expected (positive PE) and worsens when it is smaller than expected (negative PE). We found that the negative PE during appetitive and aversive taste learning is associated with increased activity of the CMA, which suggests that the CMA controls taste learning. Our findings may have implications for understanding psychological states associated with deficient learning from negative PEs, such as obesity and addictive behaviors.

Neuroticism polygenic risk predicts conversion from mild cognitive impairment to Alzheimer's disease by impairing inferior parietal surface area.

The high prevalence of conversion from amnestic mild cognitive impairment (aMCI) to Alzheimer's disease (AD) makes early prevention of AD extremely critical. Neuroticism, a heritable personality trait associated with mental health, has been considered a risk factor for conversion from aMCI to AD. However, whether the neuroticism genetic risk could predict the conversion of aMCI and its underlying neural mechanisms is unclear. Neuroticism polygenic risk score (N-PRS) was calculated in 278 aMCI patients with qualified genomic and neuroimaging data from ADNI. After 1-year follow-up, N-PRS in patients of aMCI-converted group was significantly greater than those in aMCI-stable group. Logistic and Cox survival regression revealed that N-PRS could significantly predict the early-stage conversion risk from aMCI to AD. These results were well replicated in an internal dataset and an independent external dataset of 933 aMCI patients from the UK Biobank. One sample Mendelian randomization analyses confirmed a potentially causal association from higher N-PRS to lower inferior parietal surface area to higher conversion risk of aMCI patients. These analyses indicated that neuroticism genetic risk may increase the conversion risk from aMCI to AD by impairing the inferior parietal structure.

The moderating role of conscientiousness in the temporal association of stress on sleep.

Personality traits have been associated with sleep problems and stress experience. However, their impact on objective sleep and the temporal relationship of stress on sleep has remained elusive. This study examined whether daytime stress predicts sleep the following night, and the moderating role of neuroticism and conscientiousness in this relationship. To introduce stress variability in natural daily stressors, we measured college students (N = 92) during exams (e.g. high academic stress) and at the start of new course period (e.g. low academic stress). Both objective (actigraphy) and subjective sleep, and daily self-reported stress, were measured for 14 days and personality traits once. Reported daily stress was significantly higher in the exam period compared with baseline, suggesting that our natural manipulation did indeed result in variation in stress levels. Intra-individual daily variations in stress were not associated with the following night's sleep timing, duration or fragmentation, implying that more stress during the day did not affect sleep the following night. Higher levels of neuroticism were associated with poorer daily subjective sleep quality and higher stress levels over the complete period. Neuroticism did not moderate the temporal association of stress on sleep. Conscientiousness moderated the association between intra-individual stress and sleep fragmentation, and intra-individual stress and wake-up time. This implied that highly conscientious participants experienced less sleep fragmentation and woke-up earlier after more stressful days. These results suggest an interconnected relationship among stress, sleep and personality. Focusing on one aspect, like handling stress or enhancing sleep quality, might yield positive effects on the rest.

Disease trajectory of high neuroticism and the relevance to psychiatric disorders: A retro-prospective cohort study.

BACKGROUND: Neuroticism is a psychological personality trait that has a significant impact on public health and is also a potential predisposing factor for adverse disease outcomes; however, comprehensive studies of the subsequently developed conditions are lacking. The starting point of disease trajectory in terms of genetic variation remains unclear. METHOD: Our study included 344,609 adult participants from the UK Biobank cohort who were virtually followed up from January 1, 1997. Neuroticism levels were assessed using 12 items from the Eysenck Personality Questionnaire. We performed a phenome-wide association analysis of neuroticism and subsequent diseases. Binomial tests and logistic regression models were used to test the temporal directionality and association between disease pairs to construct disease trajectories. We also investigated the association between polygenic risk scores (PRSs) for five psychiatric traits and high neuroticism. RESULTS: The risk for 59 diseases was significantly associated with high neuroticism. Depression, anxiety, irritable bowel syndrome, migraine, spondylosis, and sleep disorders were the most likely to develop, with hazard ratios of 6.13, 3.66, 2.28, 1.74, 1.74, and 1.71, respectively. The disease trajectory network revealed two major disease clusters: cardiometabolic and chronic inflammatory diseases. Medium/high genetic risk groups stratified by the PRSs of four psychiatric traits were associated with an elevated risk of high neuroticism. We further identified eight complete phenotypic trajectory clusters of medium or high genetic risk for psychotic, anxiety-, depression-, and stress-related disorders. CONCLUSION: Neuroticism plays an important role in the development of somatic and mental disorders. The full picture of disease trajectories from the genetic risk of psychiatric traits and neuroticism in early life to a series of diseases later provides evidence for future research to explore the etiological mechanisms and precision management.

The Chain Mediation Effect of Victimization and Neuroticism on the Association Between Sexual Orientation and Depressive Symptoms: A Prospective Birth Cohort Study.

This study tested whether sexual orientation differences in depressive symptoms were partially explained by the chain mediation effect of neuroticism and victimization. Using the Avon Longitudinal Study of Parents and Children from the UK (N = 4647, 36.52% men, 88% White), self-reported neuroticism, sexual orientation, and depressive symptoms were measured at age 13.5, 21, and 22 years, respectively. Childhood abuse between birth and age 11 years and the individuals' experiences of being bullied at age 17.5 years were measured as the components of victimization. Structural equation modeling was used to analyze the data. Non-heterosexual individuals reported higher depressive symptoms than heterosexual individuals, with a total effect (standardized path coefficient) of 0.590 and 0.768 for men and women, respectively. This association was partially explained by childhood abuse (indirect effect = 0.043 and 0.046 for men and women, respectively) and neuroticism directly (indirect effect = 0.036 and 0.056 for men and women, respectively). Sexual orientation differences in depressive symptoms were also partially explained by a path through increased risk of experiencing childhood abuse leading to higher levels of neuroticism (indirect effect = 0.004 and 0.009 for men and women, respectively) and by a path through higher levels of neuroticism leading to increased risk of being bullied (indirect effect = 0.004 and 0.002 for men and women, respectively). The findings suggest that while some of the association between sexual orientation and depression might be explained by neuroticism and experiences of victimization measured prospectively, these factors do not account for most of this relationship.

The relationship between postpartum negative life events and postpartum depression: a moderated mediation model of neuroticism and psychological flexibility.

BACKGROUND: Postpartum depression (PPD) is a major public health problem worldwide. Previous studies have shown that postpartum negative life events and neuroticism are both important risk factors for PPD. However, few studies have considered the role of protective factors in the influence of postpartum negative life events and neuroticism on PPD. Based on the diathesis-stress model and Acceptance and Commitment Therapy (ACT), a moderated mediating model was established to examine the mediating role of neuroticism between postpartum negative life events and PPD, as well as the moderating role of psychological flexibility in this mediating effect. METHODS: A sample of 776 parturients from three different Grade A hospitals in China were assessed using the Edinburgh Postpartum Depression Scale, the Postpartum Negative Life Events Scale, the Neuroticism Subscale of the Big Five Personality Scale, and the Acceptance and Action Questionnaire- II. RESULTS: PPD, postpartum negative life events, neuroticism, and experiential avoidance were significantly positively correlated with one another. Neuroticism partially mediated the relationship between postpartum negative life events and PPD. In this mediation model, the direct path and the second half of the mediation path were moderated by psychological flexibility. Specifically, the links between postpartum negative life events and PPD, as well as between neuroticism and PPD, were stronger when psychological flexibility was low, but weaker when psychological flexibility was high. CONCLUSIONS: The results show that psychological flexibility plays an important role in buffering the negative effects of postpartum negative life events and neuroticism on PPD. These findings provide implications for the prevention and intervention of PPD using an ACT approach.

Neuroticism and extraversion as predictors of first-lifetime onsets of depression, anxiety, and suicidality in high-risk adolescents.

There is substantial evidence that personality traits, in particular neuroticism and extraversions predict depressive and anxiety episodes as well as suicidal ideation. However, little research has examined whether these traits predict the first onset of depressive and anxiety disorders and suicidal ideation. Moreover, the few studies to date have not adjusted for pre-existing subthreshold symptoms, assessed dimensionally. In this study, 144 adolescents were assessed at baseline, 9-, and 18-month follow-ups. Neuroticism and extraversion were assessed via self-report, and depressive and anxiety disorders and suicidal ideation were assessed with diagnostic interviews. Adjusting for age, sex, and baseline symptoms, logistic regression analyses showed that neuroticism predicted the first onset of depressive disorders. However, neither neuroticism nor extraversion predicted first onsets of anxiety disorders, extraversion did not predict depressive disorders, and neither trait predicted suicidal ideation onset or severity after adjusting for baseline symptoms. Neuroticism and extraversion may respectively predispose youth to depressive or anxiety disorders but not to suicidal ideation over and above pre-existing symptoms. Results have implications for the early identification of at-risk youth and prevention of depressive and anxiety disorders and suicidal ideation.

The Paradox of Aging-Related Fears: Fear of Loneliness in Old Age as a Motivator for Loneliness Preventive Activities.

INTRODUCTION: Aging is often seen as a challenging process, prompting individuals to form emotional reactions in response to the perceived challenges associated with growing older, manifested as aging-related fears. The present study focuses on the fear of loneliness in old age, a significant concern considering the socioemotional importance of close relationships in later life. Drawing from proactive coping theory, the study explores the association between fear of loneliness and aging preparation. This research aimed to investigate whether the fear of loneliness motivates individuals to engage in activities aimed at preventing loneliness in old age. For exploratory purposes, we consider both linear and nonlinear effects at the interindividual level, as well as the intraindividual-level differences between fear levels and behavioral outcomes. In addition, we also investigate the moderating role of trait neuroticism in these associations. METHODS: Data from the "Ageing as Future (AAF)" project in Germany (N = 1,183) spanning from 2012 to 2023 were utilized. A multilevel model considered both intra- and interindividual variations, incorporating time-varying variables and covariates. RESULTS: Linear mixed model analysis revealed that increased fear of loneliness corresponded to heightened engagement in preventive activities linearly, while a quadratic term indicated an inverted U-shaped relationship. The inclusion of occasion-specific deviation scores showed that individuals were more inclined to engage in preventive activities when experiencing heightened fear of loneliness than usual. This impact of deviation in fear perception was particularly evident among those with high levels of trait neuroticism. CONCLUSION: The study reveals that fear of loneliness in old age is associated with proactive engagement in preventive activities, with those prone to higher levels of fear or worry being particularly affected. These results emphasize the importance of a moderate level of fear in driving action without succumbing to excessive pessimism or unrealistic optimism. The findings contribute to understanding the motivational role of aging-related fears and hold implications for gerontological practices, emphasizing the need for a balanced fear perception in addressing potential negative impacts of aging. Future research could explore moderators and long-term consequences of motivational aging-related fears.

Causal effects of neuroticism on postpartum depression: a bidirectional mendelian randomization study.

PURPOSE: Postpartum depression (PPD) brings adverse and serious consequences to both new parents and newborns. Neuroticism affects PPD, which remains controversial for confounding factors and reverse causality in cross-sectional research. Therefore, mendelian randomization (MR) study has been adopted to investigate their causal relationship. METHODS: This study utilized large-scale genome-wide association study genetic pooled data from three major databases: the United Kingdom Biobank, the European Bioinformatics Institute, and the FinnGen databases. The causal analysis methods used inverse variance weighting (IVW). The weighted median, MR-Egger method, MR-PRESSO test, and the leave-one-out sensitivity test have been used to examine the results' robustness, heterogeneity, and horizontal pleiotropy. The fixed effect model yielded the results of meta-analysis. RESULTS: In the IVW model, a meta-analysis of the MR study showed that neuroticism increased the risk of PPD (OR, 1.17; 95% CI, 1.11-1.25, p < 0.01). Reverse analysis showed that PPD could not genetically predict neuroticism. There was no significant heterogeneity or horizontal pleiotropy bias in this result. CONCLUSION: Our study suggests neuroticism is the risk factor for PPD from a gene perspective and PPD is not the risk factor for neuroticism. This finding may provide new insights into prevention and intervention strategies for PPD according to early detection of neuroticism.

Neuroticism affects nightmare distress through rumination.

BACKGROUND/AIMS: The role of neuroticism in predicting nightmare distress have been highlighted, and negative coping style may contribute to this relationship, but how these variables interact is limited. The present study aimed to explore how neuroticism and ruminative response contribute to producing nightmare distress, and to explore whether sex influences this relationship. METHODS: We recruited 758 university students, aged an average of 19.07. A moderated mediation model was built to examine the relationships among neuroticism, rumination, and nightmare distress (measured by dream anxiety scale), and explore whether sex could affect this relationship, using the SPSS PROCESS 3.5 macro. RESULTS: The moderated mediation analyses results showed that ruminative response-depression related can significantly partially mediate the relationship between neuroticism and dream anxiety (ß = 0.32), dream anxiety-sleep-related disturbances (ß = 0.11) and dream anxiety-daytime dysfunctions (ß = 0.21). However, the moderating effects of sex were not significant in all path from neuroticism to dream anxiety. CONCLUSION: The study provides a novel architecture on the underlying psychological mechanisms of neuroticism and nightmare distress. This interplay is assumed to be facilitated by ruminations, suggesting that interventions for individuals who suffer from nightmares may focus on their repetitive negative response strategies, especially in people with high neuroticism, irrespective of sex differences.

Supervisor's neuroticism and problematic Internet use among graduate students: the mediating role of supervisor-student relationship quality and the moderating role of fear of the supervisor's negative evaluation.

BACKGROUND: Graduate students exhibit vulnerability to problematic Internet use, which can result in adverse physical, psychological, and social consequences. However, limited studies have addressed this issue among graduate students, and even fewer have explored the unique factors contributing to their problematic Internet use. Therefore, to address this gap, the current study aims to probe the relationship between supervisor's neuroticism and problematic Internet use among graduate students, the mediating effect of the supervisor-student relationship quality, as well as the moderating effect of fear of the supervisor's negative evaluation. METHODS: A cross-sectional study was conducted in 2018 at three universities in Beijing, China. Anonymous data from 448 graduate students were collected regarding problematic Internet use, supervisor's neuroticism, supervisor-student relationship quality, and the fear of the supervisor's negative evaluation. A moderated mediation analysis was performed using Hayes' PROCESS macro (Model 14). RESULTS: Supervisor's neuroticism was positively linked to graduate students' problematic Internet use, supervisor-student relationship quality mediated the linkage, and fear of the supervisor's negative evaluation played a moderating role in the second stage. Specifically, for students lower in fear of the supervisor's negative evaluation, supervisor-student relationship quality negatively predicted students' problematic Internet use. While for the graduate students higher in fear of the supervisor's negative evaluation, supervisor-student relationship quality could not significantly predict students' problematic Internet use. The mediating effect was only significant for graduate students lower in fear of the supervisor's negative evaluation. CONCLUSIONS: This study established a theoretical model linking supervisor's neuroticism to graduate students' problematic Internet use, highlighting the potential roles of supervisor-student relationship quality and fear of the supervisor's negative evaluation. Reducing the neuroticism level of the supervisor, enhancing the quality of the supervisor-student relationship, and mitigating students' fear of the supervisor's negative evaluation will contribute to the reduction of problematic Internet use among graduate students.

The role of familial factors and neuroticism in the association between exposure to offensive behaviors at work and long-term sickness absence due to common mental disorders - a prospective twin study.

OBJECTIVES: The aim of this study was to investigate associations between exposure to work-related violence/threats and harassment, and future sickness absence (SA) due to common mental disorders (CMDs), taking familial factors (shared genetics and early-life environment) and neuroticism into account. METHODS: The study sample included 8795 twin individuals from the Swedish Twin Project of Disability Pension and Sickness Absence (STODS), including survey data from the Study of Twin Adults: Genes and Environment (STAGE). Self-reported work-related violence and/or threats as well as work-related harassment (including bullying) and national register data on SA due to CMDs were analyzed using standard logistic regression, and conditional logistic regression among complete twin pairs discordant on exposures. Individuals were followed for a maximum of 13 years. Interactions between neuroticism and exposures were assessed using both multiplicative and additive interaction analyses. RESULTS: Exposure to work-related violence/threats was associated with higher odds of SA due to CMDs when adjusting for age, sex, marital status, children, education, type of living area, work characteristics, and symptoms of depression and burnout (OR 2.11, 95% CI 1.52-2.95). Higher odds of SA due to CMDs were also found for exposure to harassment (OR 1.52, 95% CI 1.10-2.11) and a combined indicator of exposure to violence/threats and/or harassment (OR 1.98, 95% CI 1.52-2.59), compared with the unexposed. Analyses of twins discordant on exposure, using the unexposed co-twin as reference, showed reduced ORs. These ORs were still elevated but no longer statistically significant, potentially due to a lack of statistical power. No multiplicative interaction was found between neuroticism and exposure to work-related violence/threats, or harassment. However, a statistically significant additive interaction was found between neuroticism and exposure to violence/threats, indicating higher odds of SA due to CMDs in the group scoring lower on neuroticism. CONCLUSIONS: Exposure to work-related offensive behaviors was associated with SA due to CMDs. However, the results indicated that these associations may be partly confounded by familial factors. In addition, an interaction between exposure and neuroticism was suggested. Thus, when possible, future studies investigating associations and causality between offensive behaviors at work and mental health-related outcomes, should consider familial factors and neuroticism.

Risk psychosocial factors associated with postpartum depression trajectories from birth to six months.

PURPOSE: The purpose of this study was to assess the trajectory of women's depressive symptoms during the first six months postpartum, identify risk factors (sociodemographic, obstetric and personality) associated with classes, and examine associations between classes and postpartum PTSD at two months and bonding at six months. METHODS: The final sample included 212 women who gave birth in the maternity wards of a large tertiary health center that were approached at 1-3 days, two months, and six months postpartum and completed a demographic questionnaire and measures of neuroticism (BFI) and postpartum depression (EPDS), postpartum PTSD (City Birth Trauma Scale) and bonding (PBQ). Obstetric data were taken from the medical files. RESULTS: Cluster analysis revealed three distinctive clusters: "stable-low" (64.2%), "transient-decreasing" (25.9%), and "stable-high" (9.9%). Neuroticism, general-related PTSD symptoms, and bonding were associated with differences between all trajectories. Birth-related PTSD symptoms were associated with differences between both stable-high and transient-decreasing trajectories and the stable-low trajectory. No obstetric or demographic variables were associated with differences between trajectories. CONCLUSION: We suggest that screening women for vulnerabilities such as high levels of neuroticism and offering treatment can alleviate the possible deleterious effects of high-symptom depression trajectories that may be associated with their vulnerability.

Investigating solitude as a tool for downregulation of daily arousal using ecological momentary assessments.

OBJECTIVE: This research explored arousal levels as a motivating factor for solitude-seeking. We hypothesized that solitude becomes more desirable when high-arousal emotions were heightened and individual differences in extraversion and neuroticism would moderate this pattern. METHOD: We tracked individuals' hourly experiences throughout a day. We assessed their high-arousal positive (e.g., excitement) and negative emotions (e.g., tension), whether they were alone or with others, and their preferred situation at the time of the signal. We gathered 4338 surveys from 362 participants, with 103 participants completing all hourly surveys. RESULTS: Preference for and incidence of solitude changed throughout the day. Contrary to our hypotheses, lagged analyses did not indicate high-arousal emotions predicting reports of being alone an hour later. However, individuals were more likely to express a preference for solitude while experiencing high-arousal negative emotions, and less so while experiencing positive emotions. Younger individuals display stronger preference for solitude during experiences of high-arousal negative emotions. Extraversion and neuroticism did not moderate these patterns. CONCLUSIONS: The results highlight the distinctive appeal of solitude as a space for young adults to deal with negative emotions. We discussed how these findings are connected to existing literature and implications for future research.

Notes from the Underground: Seeking the top personality correlates of self-referencing.

OBJECTIVE: Self-focused language use has been frequently assumed to reflect narcissism; however, research indicates that the association between first-person singular pronouns (i.e., "I-talk") and grandiose narcissism is negligible. METHOD: To extend this literature, we progressively identify vulnerable narcissism and rumination as positive correlates of I-talk in five studies (valid Ns = 211, 475, 1253, 289, 1113). RESULTS: The first study revealed positive correlates of I-talk suggestive of vulnerable narcissism. The second study showed more directly that vulnerable narcissism was a positive correlate but that this association was attributable to shared variance with neuroticism. The third study, a preregistered effort, replicated and extended the results of the second study. The fourth and fifth studies focused on rumination in a preregistered manner. CONCLUSIONS: All the studies point to a clear distinction: While grandiose narcissism is negligibly related to I-talk, vulnerable narcissism is positively related to I-talk; moreover, rumination is a robust predictor of I-talk. A research synthesis revealed the following constructs significantly capture I-talk: depression (r = 0.10), neuroticism (r = 0.15), rumination (r = 0.14), and vulnerable narcissism (r = 0.12). The association between I-talk and neuroticism was partially mediated by rumination, providing a testable candidate mechanism for neuroticism interventions.

Defining distress tolerance in a structural model of Big Five personality domains.

OBJECTIVE: Distress tolerance (DT)-willingness to face internal discomforts-has a fuzzy boundary with neuroticism (low emotional stability), raising questions about its independent role in models of personality and mental health. METHOD: We investigated DT's overlap with neuroticism and other Big Five factors in a structural model of personality and personality disorder features in samples of university students (N = 1025), emotional disorder patients (N = 225), and substance-use patients (N = 210). RESULTS: In exploratory factor analyses, we found that DT indicators clustered with neuroticism and were essentially unrelated to other Big Five domains. Big Five personality dimensions collectively explained approximately 40%-70% of variation in DT, across different samples and methods of quantifying shared variance. CONCLUSIONS: We conclude that DT and neuroticism are near neighbors in empirical space and speculate that much of the observed correlation between DT and mental health outcomes in the literature may be carried by shared neuroticism variance. We suggest that clearer distinctions between the two constructs in empirical research could improve our understanding of DT's unique role in the development and treatment of psychopathology.

Person-specific priorities in solitude.

OBJECTIVE: People value solitude in varying degrees. Theories and studies suggest that people's appreciation of solitude varies considerably across persons (e.g., an introverted person may value solitude more than an extraverted person), and solitude experiences (i.e., on average, people may value some functions of solitude, e.g., privacy, more than other functions, e.g., self-discovery). What are the unique contributions of these two sources? METHOD: We surveyed a quota-based sample of 501 US residents about their perceived importance of a diverse set of 22 solitude functions. RESULTS: Variance component analysis reveals that both sources contributed to the variability of perceived importance of solitude (person: 22%; solitude function: 15%). Crucially, individual idiosyncratic preferences (person-by-solitude function interaction) had a substantial impact (46%). Further analyses explored the role of personality traits, showing that different functions of solitude hold varying importance for different people. For example, neurotic individuals prioritize emotion regulation, introverted individuals value relaxation, and conscientious individuals find solitude important for productivity. CONCLUSIONS: People value solitude for idiosyncratic reasons. Scientific inquiries on solitude must consider the fit between a person's characteristics and the specific functions a solitary experience affords. This research suggests that crafting or enhancing positive solitude experiences requires a personalized approach.

Serum cortisol and neuroticism for post-traumatic stress disorder over 2 years in patients with physical injuries.

AIM: This study aimed to explore the relationships between serum cortisol levels, personality traits, and the development of Post-Traumatic Stress Disorder (PTSD) over 2 years among individuals with physical injuries. METHODS: Participants were consecutively recruited from a trauma center and followed prospectively for 2 years. At baseline, serum cortisol levels were measured, and personality traits were categorized into five dimensions (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness), using the Big Five Inventory-10. The diagnosis of PTSD during follow-up (at 3, 6, 12, and 24 months post-injury) was determined using the Clinician-Administered PTSD Scale for DSM-5. Binary and multinomial logistic regression analyses were conducted to examine the interactions between cortisol levels, personality traits, and PTSD development. RESULTS: Among 923 patients analyzed, 112 (12.1%) were diagnosed with PTSD at some point during the study period, with prevalence rates decreasing from 8.8% at 3 months to 3.7% at 24 months post-injury. Direct associations between cortisol levels or personality traits and PTSD were not observed. However, a significant interaction between lower cortisol levels and higher Neuroticism in relation to PTSD risk was identified, especially during the early follow-up periods (3 to 6 months), but this association waned from the 12-month follow-up onward. CONCLUSION: Our findings reveal Neuroticism-dependent associations between serum cortisol levels and PTSD development, exhibiting temporal variations. These results suggest that PTSD development may be influenced by a complex, time-sensitive interplay of biological and psychosocial factors, underscoring the importance of considering individual differences in stress reactivity and personality in PTSD research and treatment.