The interest in the so-called dark traits in the area of individual differences is rising, and there are several instruments assessing currently the most prominent dark traits constellation, the Dark Tetrad. The first aim of this study was to examine the structure of the newly developed Short Dark Tetrad (SD4) measure in the Croatian context using latent variable modeling and testing two competing models: the confirmatory factor analytic model with four interrelated factors where items load only on their respective trait or factor, and the bifactor model with both the general “dark” factor where all the items load on and four specific orthogonal factors on which only their respective items load. The second aim of this study was to investigate the relationship between the Dark Tetrad traits and egoistic and moralistic socially desirable responding. Data were collected on a convenience sample of 439 participants (81% female) in Croatia. The results showed that, although some of the fit statistics of both tested models fell somewhat below the conventional acceptable fit threshold, their values were comparable to those from the original validation study, indicating that the Croatian version of SD4 is valid and can be used to assess the Dark Tetrad traits. Moreover, relations between the Dark Tetrad traits and egoistic and moralistic socially desirable responding point to the distinctiveness of narcissism from the rest of the Dark Tetrad.

Background/Objectives: Internalizing problems commonly increase during adolescence, yet the precise nature of their reciprocal relationship with stress remains unclear. The present study aimed to clarify the directionality of this association by disentangling stable dispositional influences from dynamic, within-person processes. Specifically, we examined whether stress and internalizing symptoms exhibit bidirectional effects over time or are primarily shaped by enduring individual differences. Methods: A large, representative sample of 1618 secondary school students (671 males, 947 females; M = 16.3 years) completed measures of subjective stress, emotional problems, and peer problems across three time points spaced six months apart. Data were analyzed using the Random Intercept Cross-Lagged Panel Model (RI-CLPM), which separates stable between-person variance from within-person fluctuations. Model fit was assessed using established criteria (CFI, TLI, RMSEA). Results: Subjective stress and emotional problems were strongly associated, whereas the relationship between stress and peer problems was weaker. In both domains, associations were largely explained by stable, trait-like individual differences. All cross-lagged effects at the within-person level were non-significant, indicating no dynamic, time-ordered influence between constructs. These findings provide no empirical support for the stress sensitization or stress generation hypotheses but are consistent with diathesis–stress models emphasizing enduring dispositional vulnerability. Conclusions: The results suggest that the link between stress and internalizing symptoms during adolescence primarily reflects stable personality-based factors, such as neuroticism or emotional instability, rather than reciprocal causal processes. Preventive interventions should target emotional regulation and resilience to mitigate the impact of dispositional vulnerabilities on adolescent mental health.

Adolescence is a developmental period characterized by increased exposure to stress and elevated vulnerability to mental health problems. The present study examined the structure of perceived stress, its longitudinal stability, and its associations with mental health in adolescents. Data were collected from a probabilistic sample of 1679 Croatian adolescents who were in the first or second year of high school at baseline and were followed across three measurement waves approximately six months apart. Perceived stress was assessed across six domains (school, future, parents, friends, romantic partners, and self), and structural equation modeling was used to test factor structure, measurement invariance across time and sex, and temporal stability. Competing models supported a hierarchical structure comprising six domain-specific factors and a higher-order general perceived stress factor. The measure demonstrated strong longitudinal and sex invariance. General perceived stress showed high stability across the three waves, despite being assessed as a current subjective experience. Perceived stress was moderately to strongly associated with depression, generalized anxiety, internalizing and externalizing symptoms, life satisfaction, and happiness, with no evidence of sex differences in these associations. These findings suggest that adolescent perceived stress is best conceptualized as a hierarchical and highly stable construct that is closely linked to multiple indicators of mental health and well-being.

The Big Five personality traits, particularly Negative Emotionality, are well-established correlates of internalizing symptoms. However, less is known about whether Disintegration, a proposed basic personality trait reflecting proneness to psychotic-like experiences and beliefs, accounts for additional individual differences in internalizing experiences in everyday life. The present study examined the incremental contribution of Disintegration beyond the Big Five to daily depression, anxiety, and rumination. A sample of 156 psychology students completed measures of Disintegration and the Big Five, followed by seven days of daily diary assessments (916 observations). Multilevel models were used to examine associations between personality traits and daily internalizing experiences. When all six personality traits were considered simultaneously, Disintegration was uniquely associated with higher daily depression (β = .25), anxiety (β = .24), and rumination (β = .17), alongside Negative Emotionality. Adding Disintegration to the Big Five increased explained variance by 10.25% for depression, 7.79% for anxiety, and 2.69% for rumination. Sensitivity analyses excluding potentially overlapping symptom-related content supported the robustness of the associations with depression and anxiety. These findings suggest that Disintegration contributes to explaining between-person differences in everyday internalizing experiences beyond established personality dimensions, extending evidence for its incremental validity to repeated daily assessments.