Trends in the Diagnostic Prevalence of Mental Disorders, 2012-2022—Using Nationwide Outpatient Claims Data for Mental Health Surveillance.

Background: Evaluations by the statutory health insurance carriers in Germany have revealed a rising prevalence of diagnoses of mental disorders, at varying levels and to varying extents. For mental health surveillance purposes, we analyzed prevalence trends across health insurance carriers, before and during the COVID-19 pandemic and stratified by diagnosis group, sex and age.

Methods: Nationwide outpatient claims data of all statutorily insured individuals for the years 2012-2022 (Nmin = 68.7 million people, Nmax = 73.7 million people) were used to determine the diagnostic prevalence of mental disorders (ICD-10 F00-F99 and five selected diagnosis groups), with stratification by sex and age. Changes over time in the spectrum of all documented mental disorders are described.

Results: Over the period 2012-2022, the percentage of people with outpatient diagnoses of mental disorders rose from 33.4% to 37.9% (a relative increase of 13.4%). In the selected diagnosis groups, the trends ranged from -11.6% to +115.8% and were generally steady over time, though stronger or stagnating trends were seen in some groups from 2020 onward. Diagnostic prevalence rose to a greater extent in male (+18.3%) than in female individuals (+10.8%) over the period 2012-2022. The greatest increases (> +15%) were seen among 11- to 17-yearolds and in 60- to 84-year-olds. The composition of the diagnosis spectrum was more stable in adults than in children and adolescents.

Conclusion: Trends in diagnostic prevalence differ across mental disorders and population subgroups and have changed in some diagnosis groups since the COVID-19 pandemic. Contextualizing research is needed for a better understanding of these developments.