The Five-Factor Model personality traits in schizophrenia: A meta-analysis

Evaluating the Exposome Score for Schizophrenia in a Transdiagnostic Psychosis Cohort: Associations With Psychosis Risk, Symptom Severity, and Personality Traits

BACKGROUND

Investigations of causal pathways for psychosis can be guided by the identification of environmental risk factors. A recently developed composite risk tool, the exposome score for schizophrenia (ES-SCZ), which controls for intercorrelations between risk factors, has shown fair to good performance. We tested the transdiagnostic psychosis classifier performance of the ES-SCZ with the Bipolar-Schizophrenia Network for Intermedial Phenotypes data and examined its relationship with clinical-level outcomes.

STUDY DESIGN

We computed the case-control classifier performance for the ES-SCZ from cross-sectional data on 1055 volunteers with psychotic diagnoses (schizophrenia, schizoaffective, bipolar psychosis) and 510 controls. Multivariate regression models were used to control for the correlations between outcomes and to correct for the effects of age, sex, and family socioeconomic status across outcomes. We estimated association for the ES-SCZ with psychosis and mood symptom severity, the 5-factor model of personality, and function across biologically defined biotypes, traditional diagnostic categories, and controls.

STUDY RESULTS

ES-SCZ classifier performance for psychosis was fair to good. ES-SCZ associations with personality factor scores were qualitatively similar between psychosis groups and controls with decreased conscientiousness and agreeableness and increased neuroticism. The patterns of associations between ES-SCZ and symptoms differed across biotypes and diagnoses. Biotype 3 and bipolar disorder had consistent within-group associations where greater exposome score predicted more severe symptoms and worse function.

CONCLUSIONS

ES-SCZ performance was consistent with previous reports in this transdiagnostic psychosis sample (adjusted odds ratio: 3.331 [2.834, 3.915], P < .001; area under the curve: 0.762 [0.735, 0.789]). Individual differences in ES-SCZ magnitude may be useful for investigating causal pathways between developmentally relevant exposures and symptomatic expression of psychosis.

Intolerance of uncertainty and psychosis: A systematic review

OBJECTIVES

Intolerance of uncertainty, the tendency to interpret and react negatively to uncertainty, is a transdiagnostic risk factor for anxiety, depression and eating-related disorders. Given the high comorbidity between anxiety, depression and schizophrenia-spectrum diagnoses (SSDs), there is potential for intolerance of uncertainty to play a role in modulating psychosis symptoms. To address this gap in our understanding, we conducted the first prospectively registered systematic review on intolerance of uncertainty and psychotic symptoms in both people with SSDs and in the general population.

METHODS

Four databases were searched (PsycINFO, Medline, Web of Science and PubMed), which identified ten studies with a total of 1503 participants that measured intolerance of uncertainty and psychosis symptoms.

RESULTS

Key findings suggest the following: (1) Intolerance of uncertainty was associated with total negative psychotic symptoms with small-medium effect sizes; (2) intolerance of uncertainty was higher in individuals with an 'at-risk' mental state for psychosis compared to controls; (3) higher intolerance of uncertainty was associated with more individual psychotic symptoms related to delusions and paranoia within clinical and nonclinical samples; and (4) there was mixed evidence for a relationship between intolerance of uncertainty and auditory hallucinations and intolerance of uncertainty and total positive symptoms in clinical samples.

CONCLUSIONS

Overall, these findings highlight that intolerance of uncertainty may be an important transdiagnostic dimension and potential treatment target for psychotic symptoms such as delusions and paranoia in people with SSDs.

Response to psychotic experiences: Impact of personality traits on perceived levels of distress

BACKGROUND

This study examined the influence of personality traits on (subclinical) positive symptom distress in patients with a psychotic disorder, their unaffected siblings and healthy controls.

METHODS

Data were obtained from the Genetic Risk and Outcome of Psychosis study (GROUP), a Dutch longitudinal multicenter cohort study. Data from 140 patients, 216 unaffected siblings and 102 healthy controls was available for baseline levels of Five Factor Model personality traits and frequency and distress due to psychotic experiences three years later, assessed with the Community Assessment of Psychic Experience questionnaire. Main effects of all five personality traits on symptom distress were investigated as well as moderating effects of Neuroticism, Extraversion and Openness on positive symptom frequency and positive symptom distress. Age, gender, symptom frequency and IQ were controlled for.

RESULTS

In both patients and siblings, the observed main effects of Neuroticism and Openness on (subclinical) positive symptom distress three years later either lost significance or had a very small effect size when controlling for covariates, mainly due to the correction for the effect of positive symptoms on personality traits at baseline. In both groups, levels of Openness at baseline moderated the association between positive symptom frequency and positive symptom distress three years later, in the direction that higher levels of Openness were associated with weaker associations between positive symptom frequency and - distress, even when covariates were controlled for.

DISCUSSION

The level of Openness to Experiences influences the perceived distress from (subclinical) positive symptoms in both patients and siblings.

Subcortical neural mechanisms of childhood trauma impacts on personality traits

This study aims to explore the relationships between childhood trauma (CT), personality traits, and subcortical structures. 171 healthy individuals completed the Childhood Trauma Questionnaire (CTQ), the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI), and underwent 3D T1-weighted MRI scans. Linear regression analyses indicated the complex relationship between CT, personality traits, and subcortical gray matter volume (GMV). Mediation analyses revealed that the right hippocampal GMV partially mediated the effects of CT on neuroticism. These findings suggest that CT affects the development of the Big Five personality traits, and alterations in subcortical structures are closely related to this process. Altered GMV in the right hippocampus may be a key neural mechanism for CT-induced neuroticism.

Long-term impact of resilience and extraversion on psychological distress during the COVID-19 pandemic: a longitudinal investigation among individuals with and without mental health disorders

Background

Over the past years, the COVID-19 pandemic has caused significant disruptions in daily routines. Although the pandemic has affected almost everyone, it has been particularly challenging for people with pre-existing mental health conditions. Therefore, this study investigated the long-term impact of resilience and extraversion on psychological distress in individuals diagnosed with mental health disorders (MHD) compared to the general population. In addition, possible gender-specific differences were investigated.

Methods

123 patients with pre-existing MHD and 343 control subjects from Austria and Italy participated in three online surveys that had been conducted after the initial wave of the COVID-19 pandemic (t0), during the second lockdown in both countries (t1), and one year thereafter (t2). Participants completed standardized questionnaires on psychological distress (Brief-Symptom-Checklist), resilience (Resilience Scale), and extraversion (Big Five Inventory). A mediation model was employed to test the primary hypothesis. Possible gender-specific differences were analyzed using a moderated mediation model.

Results

The prevalence of psychological distress was consistently higher in patients compared to controls (t0: 37.3% vs. 13.2%, t1: 38.2% vs 11.7%, t2: 37.4% vs. 13.1%). This between-group difference in psychological distress at the first follow-up was fully mediated by baseline resilience scores (65.4% of the total effect). During the second-follow up, extraversion accounted for 18% of the total effect, whereas resilience slightly decreased to 56% of the total effect. Gender was not a significant moderator in the model.

Conclusion

Next to showing that people with MHD were particularly affected by the pandemic, these findings indicate that higher degrees of resilience and extraversion are related to less long-term psychological distress. Our findings stress the relevance of strengthening resilience and extraversion and to provide mental health support in times of crises, both to patients with MHD and the general population.

Do people diagnosed with psychosis spectrum disorders share the same personality space as the general population? Big Five complemented by the proneness to psychotic-like experiences/behaviors

OBJECTIVE

Disintegration is a recently proposed broad, trait-like reconceptualization of the proneness to psychotic-like experiences/behaviors.

METHODS

We tested the assumption that the 6-factor model (Five-Factor traits plus Disintegration) was the most adequate one and that it was invariant across clinical and non-clinical populations. The clinical sample (n = 161) consisted of patients who had at least one psychotic episode, duration of illness less than 10 years, currently in remission. The general population (n = 409) was matched with the patient sample by age, gender, and education. NEO PI-R and DELTA were used to measure personality dimensions in both samples. Invariance of one to six-factor solutions was tested by Exploratory Structural Equation Modeling.

RESULTS

We found that: (a) several criteria for deciding on the number of factors to retain converged to the conclusion that the assumed 6-factor model was the most adequate one, (b) the assumed factorial structure appeared to satisfy the criteria for the scalar invariance across the two samples, (c) all nine Disintegration subdimensions separated from the Big Five, forming the Disintegration factor, and (d) Disintegration was unrelated to Openness.

CONCLUSION

The Big Five personality structure-complemented with disintegration-was invariant across individuals from the general population and patients with psychosis.

At-risk mental states and personality traits: A cluster analysis approach on a group of help-seeking young adults

INTRODUCTION

Research on the relationship between personality and psychosis onset is growing, with the goal of preventing or intervening early in patients' vulnerability. The identification of individuals with at-risk mental states has enabled the development of early intervention strategies, such as Programma 2000, a youth mental health service that was implemented in Milan (Italy).

AIMS

Focusing on the 18-25 age range-the time window with the highest incidence of psychotic onset-this study aims to identify the personality traits that may characterize the at-risk mental states and the social functioning of a group of help-seeking young adults.

METHODS

The sample includes 169 people (48.5% males and 51.5% females). Data were collected during an initial assessment that comprised the Social and Occupational Functioning Assessment Scale, the Personality Inventory for DSM-5, the Checklist ERIraos and a clinical session.

RESULTS

Results identified a three-cluster solution based on the Checklist scores: Cluster 1 'Not at psychotic risk'; Cluster 2 'At intermediate risk'; Cluster 3 'With psychotic onset'. The multivariate analysis of the variance of personality traits shows significant differences among the clusters in negative affect, detachment and disinhibition. Higher scores in these traits may distinguish individuals, not at psychotic risk from those at intermediate risk or with psychotic onset. Moreover, social functioning was found to be negatively associated with clusters of psychotic risk.

CONCLUSION

Findings from this study highlighted the need to evaluate personalized interventions targeting such personality traits that could prevent psychotic transition and promote psychological well-being.

Maladaptive personality traits in patients with recent-onset psychosis: A case-control study using the Personality Inventory for the DSM-5 (PID-5)

BACKGROUND

The relationship between maladaptive personality traits and psychotic disorders in the early stages of disease has not been thoroughly investigated, even though it is essential for developing prevention and early intervention strategies.

METHODS

The five domains and the 25 facets of the Personality Inventory for DSM-5 (PID-5) were compared between 102 patients with recent-onset psychosis (ROP) and 116 community subjects (C) with a general linear model including age and sex in the analyses. In addition, multiple linear regression models were used to identify which factors associated with the PID-5 domains in ROP, and correlation analyses were used to explore the relationship between personality traits.

RESULTS

Patients with ROP, compared to C, exhibited higher scores in four out of the five domains with medium effect sizes (Cohen's f² ≥ 0.15) in two of them: negative affect (NA, p = 0.013, f² = 0.04), detachment (DET, p < 0.001, f² = 0.15), disinhibition (DIS, p < 0.001, f² = 0.14) and psychoticism (PSY, p < 0.001, f² = 0.16). Significant group differences were observed in 15 of the 25 facets and the largest effects were observed in the facets of withdrawal (p ≤ 0.001, f² = 0.20), irresponsibility (p < 0.001, f² = 0.23) and unusual beliefs (p = 0.001, f² = 0.22). Interestingly, being on antidepressants and high scores on the positive subscale of the Positive and Negative Syndrome Scale (PANSS) were associated with high scores of NA, antagonism (ANT) and PSY.

CONCLUSIONS

Maladaptive personality traits were prominent in persons with ROP. These findings suggest that personality traits might play a role in vulnerability to psychosis and highlight the importance of evaluating personality in the early stages of psychosis.

Predictors of full recovery in patients with early stage schizophrenia spectrum disorders

To promote recovery in psychosis, targeting modifiable factors related to recovery is critical. Using more strict definition of full recovery, we examined predictors for recovery in patients with early stage schizophrenia spectrum disorders (SSD) followed up to 6.5 years. The target subjects were 375 patients with early stage SSD who had been over at least 1-year after registration and evaluated. The criteria for full recovery were having the score of the Positive and Negative Syndrome Scale (PANSS) 8-item ≤ 2 and adequate functional recovery for at least 1-year. We performed univariate Cox and stepwise Cox regression in both total and acute patients. In stepwise Cox regression, several independent predictors for recovery, i.e., negative symptoms of the PANSS, duration of untreated psychosis (DUP) and non-professional job were identified in patients with early stage SSD. In acute patients, other factors such as professional job and subjective well-being under neuroleptics were more important. The present study identified independent predictors for recovery modifiable by various psychosocial intervention and early intervention services. Moreover, it highlights the need of providing different treatment strategies depending on clinical status.

Personality traits in psychotic illness and their clinical correlates: A systematic review

This systematic review focuses on personality traits according to both the Five Factor Model and Cloninger Psychobiological Model in relation to treatment related outcome variables across all stages of clinical psychotic illness. Search of Pubmed and Psychinfo databases led to final inclusion of 65 studies, which were ranked on quality and analyzed according to the associations between personality and outcome. Main findings are that higher levels of Harm Avoidance and Neuroticism are associated with higher symptom levels, tendency towards passive coping, greater self-stigma, lower quality of life, and Harm Avoidance to higher suicidality. Higher levels of Extraversion and higher levels of Self-Directedness are associated with more preference for active coping, more intrinsic motivation and higher self-esteem. Higher Novelty Seeking is related to more substance use and aggression, in men specifically. On outcome of trauma, care consumption and duration of untreated illness no consistent associations with personality traits were found. Combined evidence from both personality models however reveals a consistent pattern of personality traits related to clinical outcome in psychotic disorder, which is discussed in a dimensional manner.

Personality traits and coping strategies in recent-onset psychosis: Associations with symptom severity and psychosocial functioning

BACKGROUND

Personality and coping may be related to symptom severity and psychosocial functioning in patients with recent-onset psychosis. This study aimed to investigate associations of personality traits and coping strategies with concurrent and follow-up symptom severity and functioning in those patients, and identify whether coping mediates relations between personality and symptoms or functioning.

METHODS

At baseline, 527 recent-onset psychosis patients (73 % male, mean age = 28 years) received assessments on personality (Neuroticism-Extraversion-Openness - Five-Factor Inventory), coping (Utrecht Coping List), symptom severity (Positive And Negative Syndrome Scale) and psychosocial functioning (Global Assessment of Functioning Scale). Of those, 149 also received symptom and functioning assessments at follow-up. Multivariable linear regression analyses were performed to assess cross-sectional associations of personality and coping with symptoms and functioning at baseline. Longitudinal associations of baseline personality and coping with follow-up symptomatic remission and functioning were analyzed with multivariable linear and binary logistic regression analyses, respectively. Lastly, it was investigated whether coping mediated associations between personality and symptoms or functioning.

RESULTS

Higher baseline Agreeableness (B = -0.019, [95%CI: -0.031; -0.007]) and Neuroticism (B = -0.017, [95%CI: -0.028; -0.006]) were associated with lower concurrent symptom severity. Reassuring Thoughts were associated with better functioning at baseline (B = 0.833, [95%CI: 0.272; 1.393]). Neither personality nor coping were associated with follow-up symptomatic remission or functioning. Coping did not mediate associations between personality and symptoms or functioning.

CONCLUSION

Only the coping strategy Reassuring Thoughts is associated with better baseline functioning in patients with recent-onset psychosis. Personality traits seem to have limited clinically relevant relations with symptom severity or functioning.

High internalized stigma among community-dwelling patients with schizophrenia: Associations with sociodemographic and clinical characteristics, personality traits and health-related quality of life

Stigma attached to schizophrenia among patients is a global concern to mental health advocates. The extent of internalized stigma experienced by consumers with schizophrenia living in the community and its correlates have not been fully explored. This study aimed to examine the prevalence of high internalized stigma and its association with sociodemographic and clinical characteristics, personality traits and aspects of health-related quality of life among community-dwelling consumers with schizophrenia. A descriptive, correlational study with a cross-sectional design was conducted with 149 consumers from outpatient psychiatric clinics of two hospitals in Taiwan. Face-to-face interviews with structured questionnaires were adopted. Data were analysed with descriptive statistics, chi-squares tests, independent t-tests and a binary logistic regression analysis. Approximately 41.6% of consumers with schizophrenia experienced high internalized stigma. In the subscales, a high experience of discrimination experience (43.6%) was reported, followed by alienation (34.2%), social withdrawal (28.2%), stereotype endorsement (24.8%) and stigma resistance (20.8%). Being younger at the onset of schizophrenia, attaining lower education, having a history of suicidality, fewer positive personality traits and poor aspects of health-related quality of life were significantly associated with high internalized stigma. Personality traits in the domains of emotional stability and conscientiousness and social and environmental aspects of health-related quality of life appeared to be the most relevant to risk of high internalized stigma. Anti-stigma initiatives coupled with personality-traits modules and modifications of health-related quality of life are suggested for mental health professionals and policy makers to ameliorate internalized stigma among community-dwelling consumers with schizophrenia.

Visual worry in patients with schizophrenia

OBJECTIVE

Worrying is a pervasive transdiagnostic symptom in schizophrenia. It is most often associated in the literature with verbal modality due to many studies of its presence in generalised anxiety disorder. The current study aimed to elucidate worry in different sensory modalities, visual and verbal, in individuals with schizophrenia.

METHOD

We tested persons with schizophrenia (n = 92) and healthy controls (n = 138) in a cross-sectional design. We used questionnaires of visual and verbal worry (original Worry Modality Questionnaire), trait worry (Penn State Worry Questionnaire) and general psychopathology symptoms (General Functioning Questionnaire-58 and Brief Psychiatric Rating Scale).

RESULTS

Both visual and verbal worry were associated with psychotic, anxiety and general symptoms of psychopathology in both groups with medium to large effect sizes. Regression analyses indicated that visual worry was a single significant predictor of positive psychotic symptoms in a model with verbal and trait worry, both in clinical and control groups (β's of 0.49 and 0.38, respectively). Visual worry was also a superior predictor of anxiety and general psychopathology severity (β's of 0.34 and 0.37, respectively) than verbal worry (β's of 0.03 and -0.02, respectively), under control of trait worry, in the schizophrenia group. We also proposed two indices of worry modality dominance and analysed profiles of dominating worry modality in both groups.

CONCLUSIONS

Our study is the first to demonstrate that visual worry might be of specific importance for understanding psychotic and general psychopathology symptoms in persons with schizophrenia.

Personality traits differentiate patients with bipolar disorder and healthy controls - A meta-analytic approach

BACKGROUND

Expression of specific personality traits has been associated with the presence and disease course of bipolar disorder (BD) in multiple studies. However, until today findings are inconsistent and potentially confounding factors such as age and gender as well as the limited sample size of previous studies make it difficult to generalize these findings. To overcome these limitations and to specify the role of personality traits in the context of BD, we performed a meta-analysis in patients with BD and healthy controls (HC), focusing on the traits of the big three and the big five: Neuroticism (N), Extraversion (E), Openness (O), Conscientiousness (C), Agreeableness (A) and Psychoticism (P).

METHODS

Two online databases (Pubmed and Web of Science) were searched systematically to identify relevant articles, including publications up to December 31, 2019. From studies that met our inclusion criteria (n = 18), we extracted relevant data of patients with BD (n = 1694) and HC (n = 2153) and calculated effect sizes for each personality trait. Further, we performed moderator analysis on gender, age, quality score and years of publication.

RESULTS

Our results indicate that patients with BD exhibit higher scores on N (large positive effect size; n = 18, g = 1.44, 95%-CI : 1.11 to 1.77) and lower scores on C (medium negative effect size; n = 6, g = -0.78, 95%-CI: -1.13 to -0.43) and E (small negative effect size; n = 13, g = -0.38, 95%-CI: -0.52 to -0.23) compared to HC. We found a moderating effect of mean age on the effect size of N with smaller differences in N levels between patients with BD and HC in older samples (-0.0437, z = - 3.96, p <0.0001). Our results were robust with respect to potential publication biases and the inclusion of potentially confounding factors such as gender, age, quality score and years of publication.

LIMITATIONS

Due to the lack of available data no subgroup analysis on the effect of mood states of patients and subtypes of BD could be performed. Moreover, our analyses are based on cross-sectional data so that findings should be interpreted with care, especially concerning causal conclusions.

CONCLUSIONS

Patients with BD showed differences in several personality traits compared to HC. Our results provide the basis for future research with focus on personality and psychopathology in patients with BD. Identifying the interaction between expressions of personality traits and BD might provide novel approaches in prevention and therapy.

The effects of patient personality traits and family cohesion on the treatment delay for patients with first-episode schizophrenia spectrum disorder

AIM

The duration of untreated psychosis (DUP) is an important prognostic indicator of schizophrenia. We explored the effects of patient personality and family relationships on delayed schizophrenia treatment.

METHODS

We prospectively included data from 169 patients diagnosed with first-episode schizophrenia. Personality traits were investigated using the Big Five Inventory (BFI-10) and family relationship was assessed employing the Family Adaptability and Cohesion Evaluation Scale-III (FACES-III). We explored patient clinical characteristics using the Positive and Negative Syndrome Scale (PANSS) and the Social and Occupational Functioning Scale (SOFAS). The DUP was defined as the time between the first appearance of psychotic symptoms and commencement of adequate antipsychotic treatment. Subjects were divided into two groups by the 3-month median DUP cutoff.

RESULTS

The average and median DUPs were 12 and 3 months, respectively. A longer DUP was associated with older age, a higher PANSS score, and a lower SOFAS score. The frequency of suicide attempts tended to be higher in the delayed treatment group (P = .055). The delayed treatment group scored significantly higher in conscientiousness factor of the BFI-10 and scored significantly lower family cohesion and adaptability factors of the FACES-III. Logistic regression showed that a longer DUP was significantly associated with higher-level conscientiousness on the BFI-10 and poorer family cohesion on the FACES-III.

CONCLUSION

Treatment delay was associated with reduced family cohesion and higher patient conscientiousness, suggesting that the family plays a crucial role in terms of patient access to mental health services when early psychotic symptoms appear.

Effects of genome-wide neuroticism-associated variants on five-factor model personality traits in schizophrenia

Patients with schizophrenia (SCZ) have characteristic personality traits compared with healthy subjects. Genome-wide significant variants for neuroticism have been reported in healthy subjects. However, the associations of these genome-wide neuroticism-associated variants with five-factor personality traits in patients with SCZ are less clear. We investigated the influences of nine independent genome-wide significant variants for neuroticism on five-factor personality traits (neuroticism, extraversion, openness, agreeableness, and conscientiousness) assessed by the NEO Five-Factor Inventory (NEO-FFI) in 107 patients with SCZ and 119 healthy controls (HCs). As expected, patients with SCZ scored significantly higher for neuroticism and lower for extraversion, openness, agreeableness and conscientiousness than HCs (p < 0.05). Of nine neuroticism-associated variants, the T allele at rs4653663 related to lower neuroticism was only significantly associated with lower neuroticism in patients with SCZ (β = -0.27, p = 3.88 × 10^-3) and in combined subjects (β = -0.15, p = 0.026). Furthermore, of other personality traits, the genetic variant was significantly associated with higher agreeableness in combined subjects (β = 0.17, p = 9.41×10^-3), higher conscientiousness in patients with SCZ (β = 0.21, p = 0.031) and lower conscientiousness in HCs (β = -0.20, p = 0.034), and nominally associated with higher extraversion in patients with SCZ (β = 0.18, p = 0.056) and in combined subjects (β = 0.13, p = 0.051). These outcomes were not affected by clinical variables. We suggest that genome-wide neuroticism-associated variant could be associated with neuroticism as well as other personality traits in schizophrenia.

Environmental factors associated with biological use and surgery in inflammatory bowel disease

BACKGROUND AND AIM

While major efforts were made studying the complex etiology of inflammatory bowel disease (IBD) including environmental factors, less is known about underlying causes leading to the heterogeneous and highly variable course of disease. As cigarette smoking cessation is the best-known environmental factor with beneficial effect in Crohn's disease (CD), more exposome factors are likely involved. Further insights into the role of the exposome in heterogeneity of disease might not only further knowledge of underlying pathways, but also allow for better risk stratification.

METHODS

Seven hundred twenty-eight IBD patients completed the validated Groningen IBD Environmental Questionnaire, collecting exposome data for 93 exposome factors. Associations with disease course, that is, for need for surgery or biological therapy, were evaluated using univariate and multivariate-adjusted logistic regression modeling.

RESULTS

No significant associations were seen after Bonferroni correction. However, 11 novel exposome factors were identified with P < 0.05. Two factors were associated with course of CD and ulcerative colitis (UC): beer (CD OR0.3/UC OR0.3) and cannabis (0.5/2.2). While in CD, carpet flooring (0.5) was associated with biological use, and four factors were associated with surgery: working shifts (1.8), appendectomy (2.4), frequent tooth brushing (2.8), and large household size (0.1). For UC, migrants more often required biologicals (10.2). Childhood underweight (3.4), amphetamine use (6.2), and cocaine use (4.8) were associated with surgery. Five factors were replicated.

CONCLUSIONS

We identified 16 environmental factors nominally associated with biological use and surgery in established IBD. These new insights form an important stepping stone to guide research on biological pathways involved, risk stratification, tailor-made interventions, and preventive strategies in IBD.

State anxiety influences P300 and P600 event-related potentials over parietal regions in the hollow-mask illusion experiment

The hollow-mask illusion is an optical illusion where a concave face is perceived as convex. It has been demonstrated that individuals with schizophrenia and anxiety are less susceptible to the illusion than controls. Previous research has shown that the P300 and P600 event-related potentials (ERPs) are affected in individuals with schizophrenia. Here, we examined whether individual differences in neuroticism and anxiety scores, traits that have been suggested to be risk factors for schizophrenia and anxiety disorders, affect ERPs of healthy participants while they view concave faces. Our results confirm that the participants were susceptible to the illusion, misperceiving concave faces as convex. We additionally demonstrate significant interactions of the concave condition with state anxiety in central and parietal electrodes for P300 and parietal areas for P600, but not with neuroticism and trait anxiety. The state anxiety interactions were driven by low-state anxiety participants showing lower amplitudes for concave faces compared to convex. The P300 and P600 amplitudes were smaller when a concave face activated a convex face memory representation, since the stimulus did not match the active representation. The opposite pattern was evident in high-state anxiety participants in regard to state anxiety interaction and the hollow-mask illusion, demonstrating larger P300 and P600 amplitudes to concave faces suggesting impaired late information processing in this group. This could be explained by impaired allocation of attentional resources in high-state anxiety leading to hyperarousal to concave faces that are unexpected mismatches to standard memory representations, as opposed to expected convex faces.

Personality and risk for serious mental illness

AIM

Certain personality traits may be related to an increased risk of developing a severe mental illness (SMI). This study examined differences in personality characteristics in a sample of youth at-risk of SMI across different clinical stages compared to healthy controls (HCs).

METHOD

Personality characteristics were assessed with the NEO-Five-Factor Inventory-3 for 41 non-help seeking asymptomatic youth with risk factors for SMI (Stage 0), 52 youth with early mood and anxiety symptoms and distress (Stage 1a), 108 youth with an attenuated psychiatric syndrome (Stage 1b), and 42 HCs.

RESULTS

Symptomatic participants scored significantly higher in neuroticism, and lower in extraversion, and conscientiousness compared to non-symptomatic participants. Compared to published norms, symptomatic participants had ratings of extraversion and conscientiousness in the low range and those with attenuated psychiatric syndromes scored high on neuroticism.

CONCLUSION

The observed personality profiles of the symptomatic stages were similar to reported profiles for discrete disorders. Early identification of this profile could aid identification of those at risk of SMI.

The Association Between Personality Traits and Dietary Choices: A Systematic Review

Increasing evidence shows how diet may play a role in improving health including mental health. Of note, personality may influence the type of diet and consequently the prognosis of medical and psychiatric conditions. The purpose of the present systematic review is to summarize the available data regarding the influence of personality on dietary habits affecting health outcomes. A search in the main databases was conducted matching the terms "personality," "personality traits" with "food choices," "food preferences," "diet," and "dietary habits." A total of 1856 articles were screened, and 24 articles were finally included. Exclusion criteria consisted of studies on animals or children, studies about eating disorders, types of diet not clearly associated with health outcomes, and studies for marketing reasons. Several studies showed that personality traits can influence both dietary choices and the type of diet, including the preference for healthy or unhealthy food. Unfavorable personality traits such as neuroticism and alexithymia (the inability to identify and describe emotions) were associated with unhealthy diet habits such as low consumption of fruit and vegetables, and the increased consumption of sugar and saturated fats. Personality seems to play a role in food selection and in the propensity to change diet. The interpretation of these results should be weighted by the different cultural contexts in which the studies were conducted and the extreme heterogeneity of tools used to assess personality and food preferences. Future research should clarify how personality can affect diet in specific populations such as patients with severe psychiatric disorders.

Personality Traits in Individuals with the Dual Diagnosis of Psychosis and Substance Use Disorders: A Comprehensive Review and Meta-Analysis

Substance abuse comorbidity is highly prevalent and is linked to detrimental outcomes in individuals with psychotic disorder, but the role of personality traits as the underlying mechanism is being increasingly underscored. This study aimed to profile temperamental risks of comorbid substance use disorder in psychotic disorders by performing meta-analyses on personality trait differences between psychotic disorders with comorbidity (dual diagnosis; DD) and without it (psychotic disorders; PSD). Methods: A systematic review of English articles using PubMed, MEDLINE, Scopus, Google Scholar, and ProQuest Dissertation and Theses. Only original empirical studies including participants with diagnosis of psychotic disorders based on structured diagnostic interviews, with and without substance use disorder evaluated with reliable and valid tests were included. Articles were independently extracted by two authors using predefined data fields, including study quality indicators. All pooled analyses were based on random-effect models. Thirteen studies (N = 885) met our inclusion criteria. All effect-size estimates were calculated based on means and standard deviations of included measures. Separate effect size estimates were obtained for four traits in the UPPS model (negative urgency, low premeditation, low perseverance, sensation seeking), four traits in the HS model (unconscientious disinhibition, negative affect, disagreeable disinhibition, positive affect) and trait anhedonia. Results: Negative urgency (four studies with 262 participants; ES = 0.59; 95% confidence interval [CI] [0.34, 0.84]), low premeditation (five studies with 349 participants; ES = 0.60; 95% CI [0.39, 0.80]), sensation seeking (seven studies with 550 participants; ES = 0.63; 95% CI [0.17, 1.09]) and unconscientious disinhibition (five studies with 291 participants; ES = 0.36; 95% CI [0.13, 0.59]) were elevated in DD than PSD. Heterogeneity of sensation seeking was significant (I² = 86.2%). Conclusions: The findings of the current meta-analysis highlight a unique profile of impulsive and externalizing trait personality domains pertaining to DD. The study emphasizes the importance of emotion regulation interventions targeting impulsivity or negative affect (i.e. negative urgency, low premeditation) in substance abuse comorbidity patients.

Personality traits in psychosis and psychosis risk linked to TSPO expression: a neuroimmune marker

Personality has been correlated with differences in cytokine expression, an indicator of peripheral inflammation; however, the associations between personality and central markers of inflammation have never been investigated in vivo in humans. Microglia are the resident macrophages of the central nervous system, and the first responders to tissue damage and brain insult. Microglial activation is associated with elevated expression of translocator protein 18kDa (TSPO), which can be imaged with positron emission tomography (PET) to quantify immune activation in the human brain. This study aimed to investigate the association between personality and TSPO expression across the psychosis spectrum. A total of 61 high-resolution [¹⁸F]FEPPA PET scans were conducted in 28 individuals at clinical high risk (CHR) for psychosis, 19 First-Episode Psychosis (FEP), and 14 healthy volunteers (HVs), and analyzed using a two-tissue compartment model and plasma input function to obtain a total volume of distribution (V_T) as an index of brain TSPO expression (controlling for the rs6971 TSPO polymorphism). Personality was assessed using the Revised NEO Personality Inventory (NEO-PI-R). We found TSPO expression to be specifically associated with neuroticism. A positive association between TSPO expression and neuroticism was found in HVs, in contrast to a nonsignificant, negative association in CHR and significant negative association in FEP. The TSPO-associated neuroticism trait indicates an unexplored connection between neuroimmune activation and personality that varies across the psychosis spectrum.

Identification of Environmental Risk Factors Associated With the Development of Inflammatory Bowel Disease

BACKGROUND AND AIMS

Multiple genetic and environmental factors are involved in the aetiology of inflammatory bowel disease [IBD] including Crohn's disease [CD] and ulcerative colitis [UC], but data on these exposome factors are difficult to identify. Several exposome factors such as smoking have been shown to be involved; as for other environmental factors, eg stress, results have been conflicting.

METHODS

We performed a case-control study including 674 IBD patients of the 1000IBD cohort, frequency-matched based on sex and age with 1348 controls from the population-based Lifelines Cohort Study. Exposome data were obtained using the validated Groningen IBD Environmental Questionnaire [GIEQ], capturing exposome factors through different stages of life using 844 items, of which 454 were applicable to study the role of 93 exposome factors in disease aetiology. Logistic regression [LR] modelling with Bonferroni correction for multiple testing was applied to estimate the multivariable-adjusted effect of each exposome factor.

RESULTS

For IBD, we identified four novel factors: stressful life events (CD odds ratio [OR] 2.61/UC OR 2.92), high perceived stress [2.29/2.67], alcohol use [0.40/0.43], and bronchial hyper-reactivity [3.04/2.36]. Four novel factors were associated with only CD: prenatal smoke exposure [1.89], having a bed partner [0.53], allergies [2.66], and cow's milk hypersensitivity [5.87]; and two solely with UC: carpet flooring [0.57] and neuroticism [1.32]. Nine factors were replicated.

CONCLUSIONS

In this study we identified 10 novel, and replicated nine previously reported, exposome factors associated with IBD. Identifying these factors is important for both understanding disease aetiology and future prevention strategies to decrease the development of IBD in genetically susceptible persons.

Assessment of coexisting psychosis and substance misuse: complexities, challenges and causality

Substance misuse worsens the prognosis for people suffering psychosis and places them at risk of being denied appropriate mental health service interventions. To increase the chances of its success, the plan of management for patients with coexisting psychosis and substance misuse should be based on a valid formulation of their problems, which in turn is dependent on the clinician having (a) a thorough understanding of the bidirectional and changing ways that substance use and mental illness symptoms can interact, (b) an awareness of their own biased implicit assumptions about causality in explaining these interactions and (c) a framework for assessment and formulation. This article addresses these three areas with reference to the evidence base and to clinical experience in a way that guides mental health clinicians in the assessment of patients with coexisting psychosis and substance misuse.

Advanced paternal age as a risk factor for neurodevelopmental disorders: a translational study

Advanced paternal age (APA) is a risk factor for several neurodevelopmental disorders, including autism and schizophrenia. The potential mechanisms conferring this risk are poorly understood. Here, we show that the personality traits schizotypy and neuroticism correlated with paternal age in healthy subjects (N = 677). Paternal age was further positively associated with gray matter volume (VBM, N = 342) in the right prefrontal and the right medial temporal cortex. The integrity of fiber tracts (DTI, N = 222) connecting these two areas correlated positively with paternal age. Genome-wide methylation analysis in humans showed differential methylation in APA individuals, linking APA to epigenetic mechanisms. A corresponding phenotype was obtained in our rat model. APA rats displayed social-communication deficits and emitted fewer pro-social ultrasonic vocalizations compared to controls. They further showed repetitive and stereotyped patterns of behavior, together with higher anxiety during early development. At the neurobiological level, microRNAs miR-132 and miR-134 were both differentially regulated in rats and humans depending on APA. This study demonstrates associations between APA and social behaviors across species. They might be driven by changes in the expression of microRNAs and/or epigenetic changes regulating neuronal plasticity, leading to brain morphological changes and fronto-hippocampal connectivity, a network which has been implicated in social interaction.

Knowledge, Attitude and Practices (KAP) towards Diet and Health among International Students in Dublin: A Cross-Sectional Study

International students may have difficulties in dietary acculturation. This study aimed to evaluate the knowledge, attitude and practices (KAP) of diet and health during the acculturation of international students. A cross-sectional survey was conducted among a convenience sample of 473 international students in Dublin. Knowledge, attitude and practices towards diet and health were evaluated by a questionnaire with open- and closed-ended questions. It was found that 45.3% of participants had a broad concept of a healthy diet, while few knew its specific contents. Furthermore, 75.3% of participants could explain the term functional food, and among them, 62.1% knew the appropriate definition of functional food. Participants who perceived their health very good and excellent were more likely to believe that their health status was determined by their own control. The consumption rate of functional food varied among regions and South and Central America students had the highest usage rate (44.5%) and Asian students had the highest daily usage rate (52.7%). Participants who were younger, single, from African and South and Central American countries, or who were in Ireland for less than one year were more likely to report dietary change after immigration. In conclusion, insufficient knowledge and self-perception towards diet and health as well as unhealthily dietary changes exist among international students living in Dublin.

Personality traits across the psychosis spectrum: A Hierarchical Taxonomy of Psychopathology conceptualization of clinical symptomatology

Psychotic disorders have varied clinical presentations, diagnostic stability is poor and other mental disorders often co-occur with the conditions. To improve the clinical and pathophysiological utility of classification systems for psychosis, it is necessary to consider how symptoms may reflect dimensions of psychopathology that extend beyond the boundaries of traditional diagnostic classifications. We examined personality deviation as a means for explaining symptom variation across individuals with serious mental illness. Participants (N = 312) with psychosis, first-degree biological relatives and healthy controls underwent comprehensive clinical evaluations that included symptom ratings and Diagnostic Statistical Manual consensus diagnoses. They completed the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (PID-5), which provides multidimensional assessment of personality disturbances and characterizes psychosis-relevant phenomena, and the Schizotypal Personality Questionnaire (SPQ), a widely accepted measure of schizotypal traits. PID-5 was comparable with SPQ in differentiating between participants with and without psychosis. Greater psychotic symptomatology and higher scores on the SPQ Cognitive-perceptual dimension were associated with higher scores on PID-5 Psychoticism. Facet-level traits showed diverse associations with existing clinical syndromes, suggesting they have utility for quantifying separable symptom dimensions that cut across existing disorders. Yet the patient groups were similar across four of the five PID-5 personality trait domains, indicating shared patterns of personality expression that challenge existing categorical delineations. © 2019 John Wiley & Sons, Ltd.

Common Taxonomy of Traits and Symptoms: Linking Schizophrenia Symptoms, Schizotypy, and Normal Personality

The associations among normal personality and many mental disorders are well established, but it remains unclear whether and how symptoms of schizophrenia and schizotypal traits align with the personality taxonomy. This study examined the joint factor structure of normal personality, schizotypy, and schizophrenia symptoms in people with psychotic disorders (n = 288) and never-psychotic adults (n = 257) in the Suffolk County Mental Health Project. First, we evaluated the structure of schizotypal (positive schizotypy, negative schizotypy, and mistrust) and normal traits. In both the psychotic-disorder and never-psychotic groups, the best-fitting model had 5 factors: neuroticism, extraversion, conscientiousness, agreeableness, and psychoticism. The schizotypy traits were placed on different dimensions: negative schizotypy went on (low) extraversion, whereas positive schizotypy and mistrust went on psychoticism. Next, we added symptoms to the model. Numerous alternatives were compared, and the 5-factor model remained best-fitting. Reality distortion (hallucinations and delusions) and disorganization symptoms were placed on psychoticism, and negative symptoms were placed on extraversion. Models that separated symptom dimensions from trait dimensions did not fit well, arguing that taxonomies of symptoms and traits are aligned. This is the first study to show that symptoms of psychosis, schizotypy, and normal personality reflect the same underlying dimensions. Specifically, (low) extraversion, negative schizotypy, and negative symptoms form one spectrum, whereas psychoticism, positive schizotypy, and positive and disorganized symptoms form another. This framework helps to understand the heterogeneity of psychosis and comorbidity patterns found in psychotic disorders. It also underscores the importance of traits to understanding these disorders.

Associations Of Personality Traits With The Capacity-Performance Discrepancy Of Functional Outcome In Patients With Schizophrenia

OBJECTIVE

Functional capacity, which indicates one's ability to perform everyday living tasks, contributes to real-world functional performance in patients with schizophrenia. However, functional capacity is sometimes not comparable with functional performance in clinical settings. We hypothesized that specific personality traits are related to this capacity-performance discrepancy of functional outcome.

METHODS

The measures in this study were the UCSD Performance-based Skills Assessment Brief (UPSA-B) for functional capacity, the Social Functioning Scale (SFS) for functional performance, and the Temperament and Character Inventory-140 (TCI-140) for personality traits. A total of 94 stable outpatients with schizophrenia were divided into four groups based on combinations of their UPSA-B and SFS cut-off points, as follows: a high capacity and high performance (HH) group, a high capacity but low performance (HL) group, a low capacity but high performance (LH) group, and a low capacity and low performance (LL) group.

RESULTS

There were no significant differences in demographics among the four groups. The LH group showed a significantly lower harm avoidance level than the LL group. The HL group showed a significantly lower persistence level than the HH group.

CONCLUSION

Lower harm avoidance may enhance functional performance, and lower persistence can limit functional performance, regardless of the primary levels of functional capacity in patients with schizophrenia. Novel and individualized psychosocial treatments considering the individual's personality traits seem to be helpful for maximizing their functional performance in the community.

Connecting Openness and the Resting-State Brain Network: A Discover-Validate Approach

In personality neuroscience, the openness-brain association has been a topic of interest. Previous studies usually started from difference in openness trait and used it to infer brain functional activity characteristics, but no study has used a "brain-first" research strategy to explore that association based on more objective brain imaging data. In this study, we used a fully data-driven approach to discover and validate the association between openness and the resting-state brain network. We collected data of 120 subjects as a discovery sample and 56 subjects as a validation sample. The Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI) was used to measure the personality characteristics of all the subjects. Using an exploratory approach based on independent component analysis of resting-state functional magnetic resonance imaging (fMRI) data, we identified a parietal network that consisted of the precuneus and inferior parietal lobe. The inter-subject similarity of the parietal memory network exhibited significant associations with openness trait, and this association was validated using the 56-subject independent sample. This finding connects the openness trait to the characteristics of a neural network and helps to understand the underlying biology of the openness trait.

Genetic Correlation Profile of Schizophrenia Mirrors Epidemiological Results and Suggests Link Between Polygenic and Rare Variant (22q11.2) Cases of Schizophrenia

New methods in genetics research, such as linkage disequilibrium score regression (LDSR), quantify overlap in the common genetic variants that influence diverse phenotypes. It is becoming clear that genetic effects often cut across traditional diagnostic boundaries. Here, we introduce genetic correlation analysis (using LDSR) to a nongeneticist audience and report transdisciplinary discoveries about schizophrenia. This analytical study design used publically available genome wide association study (GWAS) data from approximately 1.5 million individuals. Genetic correlations between schizophrenia and 172 medical, psychiatric, personality, and metabolomic phenotypes were calculated using LDSR, as implemented in LDHub in order to identify known and new genetic correlations. Consistent with previous research, the strongest genetic correlation was with bipolar disorder. Positive genetic correlations were also found between schizophrenia and all other psychiatric phenotypes tested, the personality traits of neuroticism and openness to experience, and cigarette smoking. Novel results were found with medical phenotypes: schizophrenia was negatively genetically correlated with serum citrate, positively correlated with inflammatory bowel disease, and negatively correlated with BMI, hip, and waist circumference. The serum citrate finding provides a potential link between rare cases of schizophrenia (strongly influenced by 22q11.2 deletions) and more typical cases of schizophrenia (with polygenic influences). Overall, these genetic correlation findings match epidemiological findings, suggesting that common variant genetic effects are part of the scaffolding underlying phenotypic comorbidity. The "genetic correlation profile" is a succinct report of shared genetic effects, is easily updated with new information (eg, from future GWAS), and should become part of basic disease knowledge about schizophrenia.

Unified neural structured model: A new diagnostic tool in primary care psychiatry

Overlap of multiple mental disorders in each psychiatric patient has been emphasized and the style of assessment and intervention in each patient has been gradually changed. A new practical structured model that can comprehensively explain and assess the major mental disorders integratedly has been desired. In this report, the relationships between each of the major mental disorders and each neuropsychiatric component like personality, reward system, or reinforcement learning have been comprehensively reviewed to construct a new integrated structured model for assessing the overlapped mental conditions in primary care psychiatry. This new structured model contains the following three loops: "input-output-feedback loop" (external/environmental loop), "reward-learning loop" (learning loop), and "mood-reward sensitivity loop" (mood loop), which are connected by the functions of prefrontal cortex and basal ganglia. With this new concept, overlapped mental conditions in each psychiatric patient could be theoretically much simply and logically explained. In conclusion, with the proposed psychiatric structured model, we can simply explain and understand the overlapped mental disorders in each patient. Inventing and developing such basic psychiatric structured model would offer us new diagnostic and therapeutic tools to realize personalized medicine, especially in the field of primary care psychiatry.

Glutamate Concentration in the Superior Temporal Sulcus Relates to Neuroticism in Schizophrenia

Clinical studies suggest aberrant neurotransmitter concentrations in the brains of patients with schizophrenia (SCZ). Numerous studies have indicated deviant glutamate concentrations in SCZ, although the findings are inconsistent. Moreover, alterations in glutamate concentrations could be linked to personality traits in SCZ. Here, we examined the relationships between personality dimensions and glutamate concentrations in a voxel encompassing the occipital cortex (OCC) and another voxel encompassing the left superior temporal sulcus (STS). We used proton magnetic resonance spectroscopy to examine glutamate concentrations in the OCC and the STS in 19 SCZ and 21 non-psychiatric healthy control (HC) participants. Personality dimensions neuroticism, extraversion, openness, agreeableness and conscientiousness were assessed using the NEO-FFI questionnaire. SCZ compared to HC showed higher glutamate concentrations in the STS, reduced extraversion scores, and enhanced neuroticism scores. No group differences were observed for the other personality traits and for glutamate concentrations in the OCC. For the SCZ group, glutamate concentrations in STS were negatively correlated with the neuroticism scores [r = -0.537, p = 0.018] but this was not found in HC [r(19) = 0.011, p = 0.962]. No other significant correlations were found. Our study showed an inverse relationship between glutamate concentrations in the STS and neuroticism scores in SCZ. Elevated glutamate in the STS might serve as a compensatory mechanism that enables patients with enhanced concentrations to control and prevent the expression of neuroticism.

What causes psychosis? An umbrella review of risk and protective factors

Psychosis is a heterogeneous psychiatric condition for which a multitude of risk and protective factors have been suggested. This umbrella review aimed to classify the strength of evidence for the associations between each factor and psychotic disorders whilst controlling for several biases. The Web of Knowledge database was searched to identify systematic reviews and meta-analyses of observational studies which examined associations between socio-demographic, parental, perinatal, later factors or antecedents and psychotic disorders, and which included a comparison group of healthy controls, published from 1965 to January 31, 2017. The literature search and data extraction followed PRISMA and MOOSE guidelines. The association between each factor and ICD or DSM diagnoses of non-organic psychotic disorders was graded into convincing, highly suggestive, suggestive, weak, or non-significant according to a standardized classification based on: number of psychotic cases, random-effects p value, largest study 95% confidence interval, heterogeneity between studies, 95% prediction interval, small study effect, and excess significance bias. In order to assess evidence for temporality of association, we also conducted sensitivity analyses restricted to data from prospective studies. Fifty-five meta-analyses or systematic reviews were included in the umbrella review, corresponding to 683 individual studies and 170 putative risk or protective factors for psychotic disorders. Only the ultra-high-risk state for psychosis (odds ratio, OR=9.32, 95% CI: 4.91-17.72) and Black-Caribbean ethnicity in England (OR=4.87, 95% CI: 3.96-6.00) showed convincing evidence of association. Six factors were highly suggestive (ethnic minority in low ethnic density area, second generation immigrants, trait anhedonia, premorbid IQ, minor physical anomalies, and olfactory identification ability), and nine were suggestive (urbanicity, ethnic minority in high ethnic density area, first generation immigrants, North-African immigrants in Europe, winter/spring season of birth in Northern hemisphere, childhood social withdrawal, childhood trauma, Toxoplasma gondii IgG, and non-right handedness). When only prospective studies were considered, the evidence was convincing for ultra-high-risk state and suggestive for urbanicity only. In summary, this umbrella review found several factors to be associated with psychotic disorders with different levels of evidence. These risk or protective factors represent a starting point for further etiopathological research and for the improvement of the prediction of psychosis.

Sex versus gender differences in schizophrenia: The case for normal personality differences

Schizophrenia has generally been viewed as having a unique preschizophrenia personality or destructive to the personality post-onset. This view is reflected in the scarcity of studies of personality in schizophrenia with the exception of schizotypal personality considered by many as an endophenotype of schizophrenia. What is missing is the study of personality as independent of schizophrenia and as a potential source of schizophrenia heterogeneity. In this study we examine sex versus gender as an initial effort to introduce personality as a normal variant that influences how schizophrenia is expressed. Gender, a personality construct, was associated with the presence of depression in a large sample of schizophrenia patients controlling for sex, age of onset, severity of disorder, and education. The results suggest that gender, rather than sex, as a representative personality trait may yield important insights into how schizophrenia is expressed.

Spatial and temporal expression patterns of genes around nine neuroticism-associated loci

Neuroticism is a high-order personality trait. Individuals with higher neuroticism have increased risks of various psychiatric disorders and physical health outcomes. Neuroticism is related to physiological differences in the brain. A recent genome-wide association study identified nine distinct genomic loci that contribute to neuroticism. Brain development and function depend on the precise regulation of gene expression, which is differentially regulated across brain regions and developmental stages. Using multiple publicly available human post-mortem databases, we investigated, in brain and non-brain tissues and across several developmental life stages, the spatial and temporal expression patterns of genes arising from nine neuroticism-associated loci. Functional gene-network analysis for neuroticism-associated genes was performed. The spatial expression analysis revealed that the nearest genes (GRIK3, SRP9, KLHL2, PTPRD, ELAVL2, CRHR1 and CELF4) from index single-nucleotide polymorphisms (SNPs) at the nine loci were intensively enriched in the brain compared with their representation in non-brain tissues (p<1.56×10^-3). The nearest genes associated with the glutamate receptor activity network consisted mainly of GRIK3 (FDR q=4.25×10^-2). The temporal expression analysis revealed that the neuroticism-associated genes were divided into three expression patterns: KLHL2, CELF4 and CRHR1 were preferentially expressed during postnatal stages; PTPRD, ELAVL2 and MFHAS1 were expressed during prenatal stages; and the other three genes were not expressed during specific life stages. These findings suggest that the glutamate network might be a target for investigating the neurobiological mechanisms underlying susceptibilities to higher neuroticism and several psychiatric disorders and that neuroticism is mediated by genes specifically expressed in the brain during several developmental stages.

Association of Late Adolescent Personality With Risk for Subsequent Serious Mental Illness Among Men in a Swedish Nationwide Cohort Study

IMPORTANCE

Understanding of personality as an independent risk factor for serious mental illness (SMI) remains limited. Recently, overlap between the polygenic basis for specific personality traits and specific SMIs has been identified.

OBJECTIVE

To determine the association of the adolescent personality domains of social maturity, mental energy, and emotional stability with later diagnosis of SMI.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study enrolled Swedish male military conscripts aged 18 or 19 years from January 1, 1974, through December 31, 1997. The diagnosis of an SMI was extracted from the National Patient Register for all inpatient treatment episodes in Sweden from January 1, 1974, through December 31, 2011. Data were analyzed from May 3 to September 16, 2016.

EXPOSURES

Social maturity, mental energy, and emotional stability assessed at conscription interview.

MAIN OUTCOMES AND MEASURES

Inpatient diagnoses of bipolar disorder, schizoaffective disorder, schizophrenia, and other nonaffective psychoses occurring until December 31, 2011.

RESULTS

Of the 1 017 691 men included in the cohort, 4310 developed bipolar disorder; 784, schizoaffective disorder; 4823, schizophrenia; and 5013, other nonaffective psychoses. After adjustment, with use of mean scores as a reference, low social maturity (hazard ratio [HR], 1.61; 95% CI, 1.48-1.74), low mental energy (HR, 1.34; 95% CI, 1.24-1.44), and low emotional stability (HR, 1.51; 95% CI, 1.40-1.63) were inversely associated with schizophrenia in a dose-dependent fashion. Other nonaffective psychoses displayed a similar pattern. Bipolar disorder was associated with high (HR, 1.21; 95% CI, 1.09-1.35) and low (HR, 1.12; 95% CI, 1.01-1.25) social maturity and low emotional stability (HR, 1.62; 95% CI, 1.46-1.78). Schizoaffective disorder was associated with low emotional stability (HR, 1.53; 95% CI, 1.26-1.85).

CONCLUSIONS AND RELEVANCE

Emotional stability is inversely associated with all SMI. Bipolar disorder has a unique U-shaped association with social maturity. Premorbid personality may reflect subtle changes in cerebral function, may combine with symptoms and other neurocognitive deficits to influence illness presentation, and/or may be owing to shared genetic architecture.

Personality traits are associated with the valence of future imagined events in individuals with schizophrenia

The relationships between the valence (positive or negative) of future imagined events and personality dimensions were examined in patients with schizophrenia. Correlational analyses showed that Extraversion was positively associated with the simulation of more positive future events whereas a statistical trend between Neuroticism and negative emotional valence was found. As in nonclinical individuals, personality is related to characteristics of mental time travel in schizophrenia patients.

The Relationship Between the Personality Inventory for the DSM-5 (PID-5) and the Psychotic Disorder in a Clinical Sample

Recent studies have successfully investigated the validity of the DSM-5 Alternative Model for Personality Disorders. In a final sample of 174 psychiatric patients, the present study examined the relationship between the Personality Inventory for the DSM-5 (PID-5) and syndromal psychosis. Results showed that patients diagnosed with versus without a psychotic disorder significantly differed on all PID-5 domains except Antagonism. Discriminant function analysis indicated that lower Detachment, lower Negative Affect, lower Disinhibition, and higher Psychoticism best discriminated patients with a psychotic disorder from patients with other psychiatric conditions. Subsequent stepwise discriminant analysis on all facet scales of the contributing PID-5 domains revealed that higher Unusual Beliefs, lower Depressivity, and lower Distractibility contributed the most to this differentiation. PID-5 Psychoticism scores showed moderate correlations with current psychotic symptoms and were not influenced by dose of antipsychotic medication. Our results support the ability of the PID-5 to discriminate between patients with and without psychotic disorder.