Regional differences in the assessment of depressive symptoms in the former German Democratic Republic and Federal Republic of Germany

Aim The present study investigated regional differences in response behaviour for the Patient Health Quetionnaire-9. We tested for measurement invariance and differential item and test functioning between formerly divided East- and West-Germany: the former German Democratic Republic and Federal Republic of Germany. Diverging socialization experiences in socialist versus capitalist and collectivist versus individualist systems may affect culturally sensitive assessments of mental health. Subject and Methods To test this empirically, we used factor analytic and item-response-theoretic frameworks, differentiating between East- and West-Germans by birthplace and current residence based on several representative samples of the German general population (n = 3 802). Results Across all survey, we discovered slightly higher depression sum scores for East- versus West-Germans. The majority of items did not display differential item functioning-with a crucial exception in the assessment of self-harm tendencies. The scale scores were largely invariant exhibiting only small amounts of differential test functioning. Nonetheless, they made up on average about a quarter of the observed group differences in terms of effect magnitude. Conclusion We explore possible causes and discuss explanations for the item-level differences. Overall, analyses of East- and West-German depressive symptom developments in the wake of reunification are feasible and statistically grounded.

Automated summary

The aim of this study was to investigate regional differences in response behavior for the Patient Health Questionnaire-9 between East- and West-Germany. The results showed slightly higher depression sum scores for East-Germans compared to West-Germans. Most items did not display differential item functioning, except for the assessment of self-harm tendencies. The scale scores were largely invariant, but made up a significant portion of the observed group differences in terms of effect magnitude.