In an era where mental health awareness is becoming increasingly paramount, understanding and accurately measuring psychological distress is critical across diverse cultural contexts. A groundbreaking study published in the prestigious BMC Psychology journal in 2025 sheds new light on the complexities of assessing depression, anxiety, and stress among primary schoolteachers in Spain and China. This exhaustive investigation, led by Wang, X., Cao, C.H., Liao, X.L., and their multidisciplinary team, leverages advanced psychometric methodologies to compare the Depression, Anxiety, and Stress Scale-21 (DASS-21) within two culturally distinct populations. The study’s intricate analysis not only challenges existing assumptions but also refines the tools educators and psychologists use worldwide, illuminating pathways toward more culturally sensitive mental health assessments.
The Depression, Anxiety, and Stress Scale (DASS-21) is a self-report questionnaire designed to measure three related negative emotional states—depression, anxiety, and stress—with efficiency and precision. Widely used in clinical and research settings, the instrument’s psychometric properties have been validated across numerous languages and populations. However, questions have lingered about its equivalence across diverse cultural groups, raising concerns regarding potential biases. Addressing this gap, the researchers utilized both Classical Test Theory (CTT) and Rasch analysis, an advanced probabilistic model from Item Response Theory, to dissect the nuances of DASS-21’s performance in Spanish and Chinese primary schoolteachers, a workforce particularly vulnerable to mental health challenges worldwide.
Classical Test Theory has historically served as the backbone of psychometrics, providing metrics such as reliability coefficients, item-total correlations, and factor structures. Nevertheless, CTT assumes that measurement error is uniform across all levels of the trait being measured—an assumption often violated in cross-cultural contexts. Recognizing the need for a more sophisticated approach, the research team incorporated Rasch analysis, which enables a deeper examination of individual item functioning, measurement precision at different trait levels, and the detection of differential item functioning (DIF). DIF analysis identifies items that might be biased against certain groups, leading to misinterpretations of psychological distress severity.
The focus on primary schoolteachers holds particular significance given the global recognition of their roles as frontline educators and community pillars. These professionals consistently face multifaceted stressors—from workload demands and classroom management to navigating educational reforms—that can exacerbate anxiety and depression. Comparing Spanish and Chinese teachers introduces a compelling cultural dimension, as pedagogical environments, societal expectations, and stigma surrounding mental health vary markedly between these two settings. This comparative approach allows the researchers to explore whether DASS-21 maintains psychometric robustness and cultural fairness amid such differences.
Early descriptive analyses revealed intriguing differences in symptom reporting across the groups. Chinese teachers reported lower average scores across depression and anxiety but comparable stress levels relative to their Spanish counterparts. Such initial findings underscored the importance of delving beneath surface-level scores to determine whether these variations reflected true differences in emotional states or merely artifacts of measurement bias or differential item interpretation.
The Rasch analysis found the three subscales of DASS-21—depression, anxiety, and stress—to demonstrate adequate unidimensionality, implying that each subscale effectively measured a singular underlying construct within both cultural groups. However, several items manifested significant DIF, indicating that participants from Spain and China interpreted or responded to these items differently. For instance, certain anxiety-related items exhibited varying difficulty parameters between the groups, suggesting that cultural factors could influence how anxiety symptoms are experienced and reported.
Further, the researchers observed that the DASS-21’s reliability indices, as assessed by CTT, were generally acceptable but showed subtle inconsistencies across groups. This variability underscores a fundamental psychometric challenge: instruments developed primarily in Western contexts might not seamlessly translate psychometrically when deployed cross-culturally without thorough adaptation and verification. The study’s meticulous approach to combining CTT’s traditional reliability metrics with Rasch’s finer-grained item-level diagnostics represents a methodologically rigorous avenue toward ensuring measurement equivalence.
One of the most groundbreaking aspects of this research lies in its emphasis on the practical implications for mental health screening in educational settings. The identification of DIF items suggests that certain questions may either underestimate or inflate symptom severity depending on cultural background. This finding prompts a reevaluation of raw DASS-21 scores and encourages the development of culturally calibrated scoring methods to improve diagnostic accuracy and intervention planning. The team advocates for ongoing validation of psychological tools within target populations to avoid misclassification, which can have tangible consequences for access to support services.
Moreover, the study delves into the theoretical interpretations of cultural differences in emotion expression and stigma. While Western cultural norms often promote verbal openness about mental health struggles, East Asian contexts may emphasize emotional restraint and social harmony, potentially influencing how teachers interpret and respond to questionnaire items related to anxiety or depressive feelings. Such considerations highlight the intersection between psychometrics and cultural psychology, emphasizing that measurement tools cannot be disentangled from their sociocultural milieus.
Importantly, the research underscores the flexibility and utility of Rasch analysis beyond classical psychometrics. By generating interval-level measurement and identifying non-functioning items, Rasch modeling facilitates the refinement of psychological scales and enhances their sensitivity and specificity. The application of Rasch techniques alongside CTT ensures that mental health assessments are not only statistically sound but also clinically meaningful across varied populations.
The findings also resonate with global mental health initiatives emphasizing equity. Accurate psychological assessment is a prerequisite for implementing targeted interventions, and culturally valid tools are essential in minimizing disparities in mental health diagnosis and care. In the context of primary education, where teachers’ emotional well-being directly influences pedagogical quality and student outcomes, precise screening instruments become all the more critical.
This landmark article invites further research into cross-cultural psychometrics, encouraging studies that incorporate multidimensional models and qualitative approaches to uncover the lived experiences behind quantitative scores. The methodology exemplified here sets a precedent for multidisciplinary collaboration involving psychometricians, cultural psychologists, and educational experts, highlighting the need for contextualized mental health assessments as societies become increasingly multicultural.
In conclusion, the comprehensive comparative psychometric evaluation of the DASS-21 conducted by Wang and colleagues represents a pivotal step in enhancing mental health measurement across cultures. By marrying classical and modern analytical frameworks, the study advances our understanding of how psychological distress manifests differently worldwide and how assessment tools can adapt accordingly. This work not only contributes to scientific knowledge but also has profound implications for mental health policy, educational practice, and ultimately, human well-being on a global scale.
Subject of Research: Psychometric comparison of the Depression, Anxiety, and Stress Scale-21 (DASS-21) between Spanish and Chinese primary schoolteachers.
Article Title: Comparing the psychometric evidence of the Depression, Anxiety, and Stress Scale-21 (DASS-21) between Spanish and Chinese primary schoolteachers: insights from classical test theory and rasch analysis.
Article References: Wang, X., Cao, CH., Liao, XL. et al. Comparing the psychometric evidence of the Depression, Anxiety, and Stress Scale-21 (DASS-21) between Spanish and Chinese primary schoolteachers: insights from classical test theory and rasch analysis. BMC Psychol 13, 450 (2025). https://doi.org/10.1186/s40359-025-02728-7
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