Psychometric properties and factor structure of the Temperament and Character Inventory-Revised (TCI-R) in a Croatian psychiatric outpatient sample

Dual-systems models of the genetic architecture of impulsive personality traits: neurogenetic evidence of distinct but related factors

BACKGROUND

Dual-systems models, positing an interaction between two distinct and competing systems (i.e. top-down self-control, and bottom-up reward- or emotion-based drive), provide a parsimonious framework for investigating the interplay between cortical and subcortical brain regions relevant to impulsive personality traits (IPTs) and their associations with psychopathology. Despite recent developments in multivariate analysis of genome-wide association studies (GWAS), molecular genetic investigations of these models have not been conducted.

METHODS

Using IPT GWAS, we conducted confirmatory genomic structural equation models (GenomicSEM) to empirically evaluate dual-systems models of the genetic architecture of IPTs. Genetic correlations between dual-systems factors and relevant cortical and subcortical neuroimaging phenotypes (regional/structural volume, cortical surface area, cortical thickness) were estimated and compared.

RESULTS

GenomicSEM dual-systems models underscored important sources of shared and unique genetic variance between top-down and bottom-up constructs. Specifically, a dual-systems genomic model consisting of sensation seeking and lack of self-control factors demonstrated distinct but related sources of genetic influences (rg = 0.60). Genetic correlation analyses provided evidence of differential associations between dual-systems factors and cortical neuroimaging phenotypes (e.g. lack of self-control negatively associated with cortical thickness, sensation seeking positively associated with cortical surface area). No significant associations were observed with subcortical phenotypes.

CONCLUSIONS

Dual-systems models of the genetic architecture of IPTs tested were consistent with study hypotheses, but associations with relevant neuroimaging phenotypes were mixed (e.g. no associations with subcortical volumes). Findings demonstrate the utility of dual-systems models for studying IPT genetic influences, but also highlight potential limitations as a framework for interpreting IPTs as endophenotypes for psychopathology.

Personality dimensions and treatment adherence among glaucoma patients: the role of self-transcendence

BACKGROUND

Cloninger's psychobiosocial model of personality proposes that consistent patterns of health behavior are determined by the complex interaction of different neurobiological processes of the patient's temperament and character dimensions. Poor medication adherence is a pervasive problem among glaucoma patients and can lead to increased morbidity and disability. The objective of the present study was to investigate the association between Cloninger's personality dimensions and medication adherence among glaucoma patients.

METHODS

The cross-sectional study was conducted among 113 primary open-angle glaucoma (POAG) patients. The treatment adherence was assessed through a valid and reliable self-administered questionnaire, the Culig Adherence Scale (CAS). Personality dimensions were evaluated using the abbreviated version of the Temperament and Character Inventory-Revised (TCI-140). Statistical analyses were performed using TIBCO Statistica 14.0.1. The study protocol was registered in the DRKS - German Clinical Trials Register; (DRKS-ID: DRKS00022081).

RESULTS

According to CAS, only 39.8% of patients were adherent to glaucoma treatment. Adherence was significantly negatively related only to the character dimension of Self-Transcendence (p < 0.05). No other TCI-140 dimension was significantly associated with medication adherence (p > 0.05).

CONCLUSIONS

The results suggest that POAG patients with higher scores on the Self-Transcendent personality dimension are more likely to experience difficulties adhering to medication regimen. The study highlights the importance of a holistic approach to glaucoma treatment, which takes into account not only the biological aspects of disease but also the psychosocial factors that influence patient behavior. Healthcare providers may need to consider glaucoma patients' personality dimensions, beliefs and values when developing treatment plans and strategies to improve medication adherence.

Effect of psychological factors on COVID-19 vaccine hesitancy

BACKGROUND

Vaccine hesitancy can prevent full immunization against coronavirus infectious disease-19 (COVID-19). We hypothesized that multiple factors, including an individual's personality and psychological factors, are associated with vaccine hesitancy.

METHODS

A total of 275 non-vaccinated individuals were recruited for this study. Participants completed a self-report questionnaire including sociodemographic factors, health status, COVID-19 literacy and psychological factors (depressive symptoms, generalized anxiety, somatization, illness anxiety, temperament and character). In a hierarchical logistic regression analysis, a discrete set of hierarchical variables with vaccine acceptance or hesitancy as the dependent variable was added to the demographic factors for Model 1; Model 1 + health status for Model 2; Model 2 + COVID-19 literacy for Model 3 and Model 3 + psychological factors for Model 4.

RESULTS

Models 3 and 4 could predict vaccine hesitancy. High scores on the Generalized Anxiety Disorder-7 and the Illness Attitude Scale, low confidence, low collective responsibility and low reward dependence were risk factors for vaccine hesitancy.

CONCLUSIONS

The present study demonstrates that psychological factors play critical roles in vaccine hesitancy. In addition to conventional policies that emphasize COVID-19 vaccines' safety and efficacy and the collective benefits of vaccination, a more individualized approach that considers an individual's emotions and personality is necessary.

Personality differences in patients with and without gallstones

OBJECTIVE

Presence of gallstones is associated with a range of risk factors that have previously shown associations with personality traits. Our aim was to assess the differences in personality traits between the patients with and without gallstones.

METHODS

This study used a case-control design with 308 participants from the general population, 68.2% female, mean age 49.2 (SD 9.24) years, of whom 154 (50%) participants had asymptomatic gallstones. Personality was assessed with the Temperament and Character Inventory - Revised - 140 (TCI-R-140) and depression with the Center for Epidemiological Study of Depression Scale (CESD). Cut-off ≥16 on the CES-D was used as an exclusion criterion. Subjects were also checked for metabolic risk factors and sociodemographic characteristics.

RESULTS

The group with gallstones had significantly more pronounced metabolic risk factors and higher prevalence of smoking and alcohol usage in comparison with the group without gallstones. This group also exhibited higher temperament dimension Harm avoidance (HA) and lower character dimension Self-directedness (SD). Metabolic variables differed based on character dimension Cooperativeness (CO), smoking based on temperament dimensions Novelty seeking (NS) and HA, and alcohol usage on dimension NS within the gallstones group. In the logistic regression, controlled for smoking, alcohol usage and metabolic variables, temperament dimension HA was shown to be a significant predictor of the presence of gallstones.

CONCLUSION

Our findings indicate that personality may be associated with the presence of gallstones. Future longitudinal studies addressing the complex interplay of personality traits, psychological mechanisms and the associated behavioral, metabolic and neurobiological factors, are needed.

Temperament, Character, and Subjective Well-Being in Croatian War Veterans Suffering From Posttraumatic Stress Disorder

Subjective well-being is decreased in war-affected populations. However, no previous research has investigated the role of temperament and character dimensions in life satisfaction among war veterans with posttraumatic stress disorder (PTSD). This study enrolled 148 Croatian male war veterans being treated for combat-related PTSD. The participants completed the Beck Depression Inventory-Second Edition, Satisfaction with Life Scale, and Temperament and Character Inventory-Revised. Two multivariate regression analyses with life satisfaction as a dependent variable and temperament and character dimensions, respectively, as predictor variables, were performed. Temperament dimensions harm avoidance and novelty seeking as well as character dimensions self-directedness and cooperativeness were unique predictors of life satisfaction, while controlling for the influence of depressive symptoms, education level, and employment status. Given the influence of personality dimensions on life satisfaction, the routine assessment of these dimensions might help to establish the individually tailored treatment among war veterans with PTSD.

The Psychometrics of the European Portuguese Version of the Temperament and Character Inventory-Revised

Cloninger's psychobiological model of personality integrates contributions from behavioral genetics, neurobiology, and psychology in the description of the human personality. The temperament and character inventory (TCI) is its assessment instrument. The Brazilian Portuguese version of the TCI has shown good psychometric properties. However, Portuguese spoken in Brazil presents marked and substantial differences to that spoken in Portugal, and no study has yet described the psychometrics of the European Portuguese version. The objective of this study was thus to describe the psychometric properties of the European Portuguese adult version of the TCI (the temperament and character inventory-revised (TCI-R)). This study involved 1400 Portuguese adult participants. The factorial structure of the European Portuguese version was tested using four methods: exploratory factor analysis, orthogonal procrustes rotation analysis, confirmatory factor analysis, and exploratory structural equation modeling. The integration of data coming from these methods suggested that the Portuguese version of the TCI-R presented good structural validity (as revealed by the emergence of the temperament and character structures predicted by theory) and high levels of congruence between the American and the Portuguese versions. An improvement in the goodness of fit of the models for the Portuguese population was achieved by using exploratory structural equation modeling over confirmatory factor analysis. Although some facets registered questionable consistency, all dimensions had acceptable to good consistency (all ≥ .79). These results confirm the validity of the Portuguese TCI-R and its adequacy for use in European Portuguese samples.