Lockdown COVID‑19: a stress test revealing more about the mental health system than psychopathology—A comparative analysis between Austria, Germany, and Italy

Background: This study examined whether the COVID-19 pandemic produced diagnosis-specific and cross-nationally reproducible alterations in psychiatric admissions, or whether observed variations primarily reflected organizational responses. We compared psychiatric inpatient services from Austria and Germany-two hospital-centered systems with similar pre-pandemic structures-and used Italy as a contrasting community-based model. Methods: We conducted a retrospective multicenter observational study including all psychiatric hospitalizations between 2017 and 2020. Temporal admission trends were analyzed bi-weekly for each ICD-10 diagnostic group. Generalized Linear Models (Poisson family) were used to model the effects of Diagnosis, Year (2020 vs. pre-2020), Week, and Country, and their interactions. Diagnostic categories were grouped following ICD-10, with F10 (alcohol-related disorders) analyzed separately from other substance-use disorders to capture differences between planned and emergency admissions. Results: < 0.05), consistent across diagnoses except for F10. Alcohol-related disorders showed country-specific trajectories, reflecting service reorganization-bed closures in Austria versus stable capacity in Germany. No other diagnosis exhibited reproducible temporal deviations across countries, indicating that the pandemic affected admission organization rather than disorder-specific psychopathology. A supplementary comparison including Italy showed that, while Austria and Germany experienced a decline in total hospitalizations (-16 and -10%, respectively), Italy remained stable (+12%), suggesting greater resilience of its community-based system. Conclusion: The pandemic did not induce diagnosis-specific increases in acute psychiatric admissions but substantially altered their temporal organization. Differences across countries highlight how healthcare structure-particularly the integration of territorial and inpatient services-modulates system resilience under crisis conditions.