Trends in the Diagnostic Prevalence of Mental Disorders, 2012-2022­Using 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-year-olds 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.

[A Continuous Literature Review for Mental Health Surveillance during the Covid-19 Pandemic in Germany - Method, Selected Results and Lessons Learned]. / Kontinuierliches Literaturreview zur Surveillance der psychischen Gesundheit in Deutschland während der COVID-19-Pandemie ­ Methode, ausgewählte Ergebnisse und Lessons Learned.

In order to provide an up-to-date overview on changes in population's mental health during the COVID-19 pandemic, a continuous literature review was conducted. Building on a rapid review, systematic and hand searches were conducted monthly until December 31, 2022. Studies were assessed for observation periods, risk of bias and outcomes. Trends in depressive symptoms in adults were summarized by vote counting. 102 publications were included from 62 studies in the adult population. Studies declined over the course of the pandemic. Overall, 37% of the studies and 56% of the publications can assess trends in the population reliably. Among evidence for changes in depressive symptoms deteriorations predominated at last. The heterogeneity of results published by the end of 2022 limits evidence syntheses. Evidence of deterioration requires further surveillance. A continuous review can indicate evidence gaps at an early stage.

The Agreement Between Diagnoses as Stated by Patients and Those Contained in Routine Health Insurance Data­Results of a Data Linkage Study.

BACKGROUND: The frequency of medical diagnoses is a figure of central importance in epidemiology and health services research. Prevalence estimates vary depending on the underlying data. For a better understanding of such discrepancies, we compared patients' diagnoses as reported by themselves in response to our questioning with their diagnoses as stated in the routine data of their health insurance carrier. METHODS: For 6558 adults insured by BARMER, one of the statutory health insurance carriers in Germany, we compared the diagnoses of various illnesses over a twelve-month period, as reported by the patients themselves in response to our questioning (October to December 2021), with their ICD-10-based diagnosis codes (Q4/2020-Q3/2021). The degree of agreement was assessed with two kappa values, sensitivity, and specificity. RESULTS: The patients' stated diagnoses of diabetes and hypertension agreed well or very well with their diagnosis codes, with kappa and PABAK values near 0.8, as well as very high sensitivity and specificity. Moderately good agreement with respect to kappa was seen for the diagnoses of heart failure (0.4), obesity, anxiety disorder, depression, and coronary heart disease (0.5 each). The poorest agreement (kappa ≤ 0.3) was seen for post-traumatic stress disorder, alcohol-related disorder, and mental and somatoform disorder. Agreement was worse with increasing age. CONCLUSION: Diagnoses as stated by patients often differ from those found in routine health insurance data. Discrepancies that can be considered negligible were found for only two of the 11 diseases that we studied. Our investigation confirms that these two sources of data yield different estimates of prevalence. Age is a key factor; further reasons for the discrepancies should be investigated, and avoidable causes should be addressed.

Time trends in mental health indicators in Germany's adult population before and during the COVID-19 pandemic.

Background: Times of crisis such as the COVID-19 pandemic are expected to compromise mental health. Despite a large number of studies, evidence on the development of mental health in general populations during the pandemic is inconclusive. One reason may be that representative data spanning the whole pandemic and allowing for comparisons to pre-pandemic data are scarce. Methods: We analyzed representative data from telephone surveys of Germany's adults. Three mental health indicators were observed in ~1,000 and later up to 3,000 randomly sampled participants monthly until June 2022: symptoms of depression (observed since April 2019, PHQ-2), symptoms of anxiety (GAD-2), and self-rated mental health (latter two observed since March 2021). We produced time series graphs including estimated three-month moving means and proportions of positive screens (PHQ/GAD-2 score ≥ 3) and reports of very good/excellent mental health, as well as smoothing curves. We also compared time periods between years. Analyses were stratified by sex, age, and level of education. Results: While mean depressive symptom scores declined from the first wave of the pandemic to summer 2020, they increased from October 2020 and remained consistently elevated throughout 2021 with another increase between 2021 and 2022. Correspondingly, the proportion of positive screens first decreased from 11.1% in spring/summer 2019 to 9.3% in the same period in 2020 and then rose to 13.1% in 2021 and to 16.9% in 2022. While depressive symptoms increased in all subgroups at different times, developments among women (earlier increase), the youngest (notable increase in 2021) and eldest adults, as well as the high level of education group (both latter groups: early, continuous increases) stand out. However, the social gradient in symptom levels between education groups remained unchanged. Symptoms of anxiety also increased while self-rated mental health decreased between 2021 and 2022. Conclusion: Elevated symptom levels and reduced self-rated mental health at the end of our observation period in June 2022 call for further continuous mental health surveillance. Mental healthcare needs of the population should be monitored closely. Findings should serve to inform policymakers and clinicians of ongoing dynamics to guide health promotion, prevention, and care.

Changes in mental health in the German child and adolescent population during the COVID-19 pandemic - Results of a rapid review.

Background: This rapid review examines changes in the mental health of the German child and adolescent population during the COVID-19 pandemic. Methods: The basis are 39 publications, which were identified by means of systematic literature search (until 19.11.2021) and manual search. The databases of the included publications were systematized with regard to their representativeness for the general population, and the indicators used were categorized with regard to the depicted constructs and their reliability. Results: The large majority of the studies took place at the beginning of the pandemic until the summer plateau 2020. Representative studies mainly reported high levels of pandemic-related stress, increases in mental health problems, and negative impacts on the quality of life. Non-representative studies showed mixed results. Vulnerable groups could only be identified to a limited extent. Both routine and care-related data showed declines in the outpatient and inpatient service utilisation during the various waves of the pandemic followed by catch-up effects. Children and adolescents turned out to be more vulnerable during the pandemic compared to adults, but their stress levels varied with the waves of the pandemic and the related containment measures. Conclusions: A future forward-looking crisis and pandemic management requires a close-knit and continuous surveillance of the mental health of children as well as an improved identification of risk groups.

[Mental health surveillance at the Robert Koch Institute - strategies for monitoring the mental health of the population]. / Mental Health Surveillance am Robert Koch-Institut ­ Strategien zur Beobachtung der psychischen Gesundheit der Bevölkerung.

The continuous and systematic surveillance of the health of populations is fundamental for effective public health practice. In light of the growing importance of mental health within population health, a Mental Health Surveillance for Germany is being established at the Robert Koch Institute. Its aim is to continually provide reliable information on the current state and development of the mental health of the population.Three surveillance strategies are currently being pursued: 1) Regular comprehensive assessments aim to describe the mental health status of the population using a wide range of indicators and data sources and to observe long-term developments. They build on existing work in epidemiology and health services research. 2) High-frequency monitoring of a selection of indicators is used for the early detection of trends. 3) A continuous literature review collates current findings on mental health developments in the COVID-19 pandemic on a monthly basis. The latter two strategies were implemented in response to new information needs in the pandemic.This paper describes and discusses these three strategies and their functions, limitations, and potential for development. Their results are communicated through different forms of reporting and serve to identify needs for action and research in public mental health. The further development and long-term operation of the Mental Health Surveillance as a whole has the potential to facilitate the achievement of public mental health objectives and to contribute on different levels to the improvement of population health.

Mental health indicators for children and adolescents in OECD countries: a scoping review.

Background: This scoping review is a further step to build up the Mental Health Surveillance System for Germany. It summarizes and analyzes indicators used or described in Organization for Economic Co-operation and Development (OECD) countries for public mental health monitoring in children and adolescents aged 0-18 years. Methods: We searched PubMed-MEDLINE, PsycINFO, Cochrane Databases, and Google Scholar from 2000 to September 2022. The search used five general keyword categories: 1) "indicators/monitoring/surveillance" at the population level, 2) "mental/psychological," 3) "health/disorders," 4) "children and adolescents," and 5) 38 OECD countries. The search was complemented with an extensive grey literature search, including OECD public health institutions and an internet search using Google. A predefined set of inclusion and exclusion criteria was applied. Results: Over 15,500 articles and documents were screened (scientific search N = 10,539, grey literature search more than 5,000). More than 700 articles and documents have been full-text assessed, with 382 being ultimately included. Out of 7,477 indicators extracted, an initial set of 6,426 indicators met our inclusion criteria for indicators. After consolidating duplicates and similar content, this initial set was categorized into 19 topics, resulting in a final set of 210 different indicators. The analysis highlighted an increasing interest in the topic since 2008, but indicators for the younger age, particularly those aged 0 to 2 years, were less readily available. Conclusion: Our research provides a comprehensive understanding of the current state of mental health indicators for children and adolescents, identifying both (1) indicators of public mental health noted in a previous scoping review on adults and (2) new indicators specific to this age group. These findings contribute to the development of effective public health surveillance strategies for children and adolescents and inform future research in this field.

The Burden of Disease in Germany at the National and Regional Level.

BACKGROUND: .Summary measures such as disability-adjusted life years (DALY) are becoming increasingly important for the standardized assessment of the burden of disease due to death and disability. The BURDEN 2020 pilot project was designed as an independent burden-of-disease study for Germany, which was based on nationwide data, but which also yielded regional estimates. METHODS: DALY is defined as the sum of years of life lost due to death (YLL) and years lived with disability (YLD). YLL is the difference between the age at death due to disease and the remaining life expectancy at this age, while YLD quantifies the number of years individuals have spent with health impairments. Data are derived mainly from causes of death statistics, population health surveys, and claims data from health insurers. RESULTS: In 2017, there were approximately 12 million DALY in Germany, or 14 584 DALY per 100 000 inhabitants. Conditions which caused the greatest number of DALY were coronary heart disease (2321 DALY), low back pain (1735 DALY), and lung cancer (1197 DALY). Headache and dementia accounted for a greater disease burden in women than in men, while lung cancer and alcohol use disorders accounted for a greater disease burden in men than in women. Pain disorders and alcohol use disorders were the leading causes of DALY among young adults of both sexes. The disease burden rose with age for some diseases, including cardiovascular diseases, dementia, and diabetes mellitus. For some diseases and conditions, the disease burden varied by geographical region. CONCLUSION: The results indicate a need for age- and sex-specific prevention and for differing interventions according to geographic region. Burden of disease studies yield comprehensive population health surveillance data and are a useful aid to decision-making in health policy.

[Using emergency department routine data for the surveillance of suicide attempts and psychiatric emergencies]. / Nutzung von Routinedaten aus Notaufnahmen zur Surveillance von Suizidversuchen und psychiatrischen Notfällen.

BACKGROUND: The occurrence of suicide attempts is a key indicator of the population's mental health and therefore belongs in the domain of Mental Health Surveillance at the Robert Koch Institute. No data source is currently being used systematically for the continuous observation of psychiatric emergencies (including suicide attempts) in Germany. Therefore, the use of routine data from emergency departments will be explored in this work. METHODS: We included routine data from 12 emergency departments between 1 January 2018 and 28 March 2021. We developed syndrome definitions for suicide attempts, psychiatric emergencies based on combinations of chief complaints, and diagnoses from patients presenting with psychopathological symptoms. A descriptive analysis over time was presented and stratified by age and sex. RESULTS: In total 1,516,883 emergency department attendances were included, among which we identified 5,133 cases (0.3%) as suicide attempts, 31,085 (2.1%) as psychiatric emergencies, and 34,230 (2.3%) as cases with psychiatric symptoms. Among psychiatric emergencies, 16.5% presented because of a suicide attempt. Of cases presenting with a suicide attempt, 53.4% were male and 20.2% were aged between 25 and 34 years. Cases identified by all 3 syndrome definitions and their temporal variations could be displayed over the entire observation period. CONCLUSION: Syndromic surveillance using emergency department data indicates a potential for continuous surveillance of suicide attempts and psychiatric emergencies and provides a basis for further validation and analysis. The display of changes in real time extends the current research opportunities for psychiatric emergencies in Germany. Systematic surveillance of suicide attempts can contribute to evidence-based suicide prevention.

Indicators for Public Mental Health: A Scoping Review.

Background: To monitor population mental health, the identification of relevant indicators is pivotal. This scoping review provides a comprehensive overview of current indicators representing the various fields of public mental health core topics. It was conducted as a first step to build up a Mental Health Surveillance for Germany. Methods: We conducted a systematic MEDLINE search via PubMed. This search was supplemented by an extensive examination of the websites of relevant national as well as international institutions in the context of public mental health and an additional internet search via Google. To structure the data, an expert-based focus group identified superordinate topics most relevant to public mental health to which the identified indicators could be assigned to. Finally, the indicator set was screened for duplicates and appropriate content to arrive at a final set. Results: Within the various search strategies, we identified 13.811 records. Of these records, a total of 365 records were processed for indicator extraction. The extracted indicators were then assigned to 14 topics most relevant to public mental health as identified by the expert-based focus group. After the exclusion of duplicates and those indicators not meeting criteria of specificity and target group, the final set consisted of 192 indicators. Conclusion: The presented indicator set provides guidance in the field of current concepts in public mental health monitoring. As a comprehensive compilation, it may serve as basis for future surveillance efforts, which can be adjusted and condensed depending on the particular monitoring focus. Our work provides insights into established indicators included in former surveillance work as well as recent, not yet included indicators reflecting current developments in the field. Since our compilation mainly concludes indicators related to mental health in adults, it should be complemented with indicators specific to children and adolescents. Furthermore, our review revealed that indicators on mental health promotion and prevention are underrepresented in current literature of public mental health and should hence be focused on within future research and surveillance.

The Excess Costs of Depression and the Influence of Sociodemographic and Socioeconomic Factors: Results from the German Health Interview and Examination Survey for Adults (DEGS).

INTRODUCTION: The aim of this study was to estimate excess costs of depression in Germany and to examine the influence of sociodemographic and socioeconomic determinants. METHODS: Annual excess costs of depression per patient were estimated for the year 2019 by comparing survey data of individuals with and without self-reported medically diagnosed depression, representative for the German population aged 18-79 years. Differences between individuals with depression (n = 223) and without depression (n = 4540) were adjusted using entropy balancing. Excess costs were estimated using generalized linear model regression with a gamma distribution and log-link function. We estimated direct (inpatient, outpatient, medication) and indirect (sick leave, early retirement) excess costs. Subgroup analyses by social determinants were conducted for sex, age, socioeconomic status, first-generation or second-generation migrants, partnership, and social support. RESULTS: Total annual excess costs of depression amounted to €5047 (95% confidence interval [CI] 3214-6880) per patient. Indirect excess costs amounted to €2835 (1566-4103) and were higher than direct excess costs (€2212 [1083-3341]). Outpatient (€498), inpatient (€1345), early retirement (€1686), and sick leave (€1149) excess costs were statistically significant, while medication (€370) excess costs were not. Regarding social determinants, total excess costs were highest in the younger age groups (€7955 for 18-29-year-olds, €9560 for 30-44-year-olds), whereas total excess costs were lowest for the oldest age group (€2168 for 65+) and first-generation or second-generation migrants (€1820). CONCLUSIONS: Depression was associated with high excess costs that varied by social determinants. Considerable differences between the socioeconomic and sociodemographic subgroups need further clarification as they point to specific treatment barriers as well as varying treatment needs.

Utilisation of outpatient medical services in Germany - Results from GEDA 2019/2020-EHIS.

Outpatient health care provision plays an important role in the identification and treatment of health problems. Data are needed on the utilisation of health care services and their determinants to enable health policy decision-making and needs-based care provision. The analyses set out in this article are based on current data on the utilisation of outpatient health care services. The data stem from the German Health Update (GEDA 2019/2020-EHIS), a nationwide cross-sectional survey of the resident population in Germany that is undertaken as part of the health monitoring conducted at the Robert Koch Institute. Around 80% of the population aged 18 or over were treated at least once within twelve months by a general practitioner, 60% by a specialist, and 10% received psychiatric or psychotherapeutic treatment. Less than half of those eligible had had a stool test during the past two years, and just over half had had a colonoscopy in the past ten years. Around 80% of women and 70% of men had had their blood pressure checked within the last year, and 60% had had their blood cholesterol or blood sugar levels monitored. Over 50% reported that they had taken medically prescribed drugs in the past two weeks. In general, most of the indicators under study suggest that utilisation increases with age and that utilisation is higher among women than men, with the exception of psychiatric and psychotherapeutic services, among others.

Establishing a Mental Health Surveillance in Germany: Development of a framework concept and indicator set.

In the course of the recognition of mental health as an essential component of population health, the Robert Koch Institute has begun developing a Mental Health Surveillance (MHS) system for Germany. MHS aims to continuously report data for relevant mental health indicators, thus creating a basis for evidence-based planning and evaluation of public health measures. In order to develop a set of indicators for the adult population, potential indicators were identified through a systematic literature review and selected in a consensus process by international and national experts and stakeholders. The final set comprises 60 indicators which, together, represent a multidimensional public health framework for mental health across four fields of action. For the fifth field of action 'Mental health promotion and prevention' indicators still need to be developed. The methodology piloted proved to be practicable. Strengths and limitations will be discussed regarding the search and definition of indicators, the scope of the indicator set as well as the participatory decision-making process. Next steps in setting up the MHS will be the operationalisation of the single indicators and their extension to also cover children and adolescents. Given assured data availability, the MHS will contribute to broadening our knowledge on population mental health, supporting a targeted promotion of mental health and reducing the disease burden in persons with mental disorders.

Mental health of the adult population in Germany during the COVID-19 pandemic. Rapid Review.

This rapid review examines how the mental health of adults in the general population in Germany changed during the COVID-19 pandemic. We conducted a systematic literature search and included 68 publications as of July 30 2021. The underlying studies were classified according to their suitability for representative statements for the general population and for estimating changes in mental health over time. In addition, the observation period and operationalisation of outcomes were considered. The first wave of infection and the summer plateau were mapped by 65% of the studies. Studies that were particularly suitable for representative statements due to their research design showed mixed results, which tend to indicate a largely resilient adult population with a proportion of vulnerable individuals. A predominantly negative development of mental health was described by results from more bias-prone study designs. Routine data analyses showed decreases in outpatient and especially inpatient care, increased use of a crisis service, mixed results for outpatient diagnoses, incapacity to work and mortality as well as indications of shifts in the spectrum of diagnoses. As the current evidence is ambiguous, generalised statements should be reflected in favour of a differentiated view. There is a need for research on the further course of the pandemic, specific risk groups and the prevalence of mental disorders.

Trends in prevalence of depression in Germany between 2009 and 2017 based on nationwide ambulatory claims data.

BACKGROUND: Studies based on health insurance funds unanimously indicate a rise in administrative prevalence of depression, while population surveys with standardized diagnostic procedures do not. We describe recent trends in the prevalence of depressive disorders as diagnosed in routine care from 2009-2017 in Germany. METHODS: We used nationwide ambulatory claims data from all residents with statutory health insurance, covering 87% of the total population. Cases were defined as persons with at least one documented diagnosis of depression (ICD-10-GM codes: F32, F33 or F34.1). The administrative prevalence was computed for each year according to age, sex, degree of urbanization and severity of depression diagnosis. RESULTS: The prevalence increased from 12.5% in 2009 to 15.7% in 2017 (+26%). Overall, women were twice as likely as men to receive a diagnosis, although the prevalence increased more strongly in men compared to women (+40% vs. +20%). Age- and sex-stratified analyses revealed the highest prevalence increase in adolescents and young men at the ages of 15-19 years (+95%) and 20-25 years (+72%). Rural areas with a low population density showed the highest rise in administrative prevalence (+34%), while big urban municipalities showed the lowest (+25%). LIMITATIONS: Administrative claims data rely on diagnoses coded for billing purposes and thus depend on coding practice as well as patients' help seeking behavior. CONCLUSIONS: Depressive disorders are of increasing importance in ambulatory health care in Germany. Parts of the increase may be attributed to changing cultural constructions of mental health along with the expansion of mental health care supply.

[Are Diagnoses of Depression Increasing all over the Population? - Prevalence of Self-Reported Clinician Diagnosed Depression in the 2009 and 2012 Representative Cross-Sectional "German Health Update (GEDA)" Surveys]. / Nehmen Depressionsdiagnosen bevölkerungsweit zu?

OBJECTIVE: The study examines, if the increase in self-reported clinician diagnosed depression appears throughout the whole population and to what extent it can be explained by changes in the population structure over time. METHODS: Stratified trend analysis of survey data from 2009 and 2012, adjusted for population characteristics. RESULTS: 12-month-prevalence of self-reported clinician diagnosed depression rose from 6.3 % up to 8.0 %. The trend can be observed in all population sub-groups and dropped by 13.5 % with adjustment. CONCLUSION: The increase in prevalence is not limited to groups at risk and can only partly be explained by their development over time.

[Healthcare epidemiology of mental disorders : Why is the prevalence not declining despite growing provision of care?] / Versorgungsepidemiologie psychischer Störungen : Warum sinken die Prävalenzen trotz vermehrter Versorgungsangebote nicht ab?

In Germany, the significant increase of healthcare provision and service use in recent decades has not resulted in a decreasing prevalence of mental disorders.Three explanations for this phenomenon are considered: 1) prevention and the healthcare system are insufficient and ineffective, 2) the success of the healthcare service is masked by growing morbidity due to increasing societal risks, and 3) a fundamental shift towards a psychological culture accounts for an increasing perception and treatment of mental disorders and their symptoms at the same time. In order to review these three theoretical approaches, results from population-based health surveys and healthcare research in Germany as well as the international debate are presented and discussed.The present results provide evidence for each of the three explanations: 1) problems with implementation of preventive actions and access to healthcare services are well documented, 2) influences of the multifaceted development of risk factors on the prevalence and disease burden of mental disorders cannot be ruled out, and 3) a growing mental health literacy implies that problems (in everyday life) are currently more often interpreted and treated psychologically.For the purpose of evaluating changes in the healthcare system, not only should the prevalence of mental disorders be considered, but also incidence (and their potential reduction by preventive measures) as well as indicators of need for treatment (i. e. functional impairment) and mortality (i. e. suicides and reduced life expectancy).

[Prevalences of Depression Among Adults: Comparative Analysis of a Nationwide Survey and Routine Data]. / Prävalenzen von Depressionen bei Erwachsenen ­ eine vergleichende Analyse bundesweiter Survey- und Routinedaten.

AIM: There are differences in the prevalence estimates of depressive disorders based on primary and secondary data. The reasons for this are, for instance, the use of divergent indicators and varying observation periods. This study examines the prevalence of depressive disorders using survey and routine data for a comparable survey period and age range. Effects of differences between data sources and indicators are estimated. METHODS: For 2010, 3 indicators are compared: in a population survey collected a) self-reported medical diagnosis of depression, b) diagnosis of depressive disorders identified by clinical interviews and c) administrative depression diagnoses collected from routine data of a statutory health insurance. In sensitivity analyses, privately insured participants of the population survey were excluded, and insured persons with care needs were excluded from routine data. The definition of administrative depression diagnosis was varied depending on the frequency of coded diagnoses and the specificity of the diagnoses. RESULTS: The highest prevalence (9.8%) was found for depression diagnoses from administrative data, the lowest prevalence (5.9%) in self-reported medical diagnoses of depression in the population survey. The prevalence of depression identified by clinical interviews was 8.4%. Differing age and gender-related courses of illness were found. The administrative prevalence dropped significantly if unspecific diagnoses (F3x.8, F3x.9) were excluded. DISCUSSION: Depending on the definition of depression diagnoses used in administrative data, there was a reduction in differences of prevalence compared to the self-reported medical diagnoses. Differences in prevalence based on a diagnosis of a depressive disorder identified in a clinical interview remained stable, which indicates different groups of persons.

Time trends in depression prevalence and health-related correlates: results from population-based surveys in Germany 1997-1999 vs. 2009-2012.

BACKGROUND: Although an "epidemic" of depression is frequently claimed, empirical evidence is inconsistent, depending on country, study design and depression assessment. Little is known about changes in depression over time in Germany, although health insurance companies report frequency increases. Here we examined time trends in depression prevalence, severity and health-related correlates in the general population. METHODS: Data were obtained from the mental health module of the "German Health Interview and Examination Survey for Adults" (2009-2012, n = 3265) and the mental health supplement of the "German National Health Interview and Examination Survey 1998" (1997-1999, n = 4176), excluding respondents older than 65. 12-month major depressive disorder (MDD), severity and symptoms were assessed based on the WHO Composite International Diagnostic Interview. Health-related quality of life (SF-36), self-reported sick days or days with limitations in normal daily life activities were examined, too. Calculations were carried out population-weighted. Additional age-standardized analyses were conducted to account for demographic changes. RESULTS: Overall, MDD 12-month prevalence remained stable at 7.4%. Women showed a shifted age distribution with increased prevalence at younger ages, and increasing MDD severity. Time trends in health-related correlates occurred both in participants with and without MDD. Mental health disability increased over time, particularly among men with MDD, reflected by the mental component score of the SF-36 and days with activity limitation due to mental health problems. Demographic changes had a marginal impact on the time trends. CONCLUSIONS: In contrast to the ongoing international debate regarding increased depression rates in western countries, we found no increase in overall MDD prevalence in Germany over a long period. In conclusion, increased depression frequencies in national health insurance data and growing health care costs associated with depression are not attributable to overall prevalence changes at a population level. However, shifted age distribution and increased severity among women may reflect a rising depression risk within this specific subgroup, and changes in health-related correlates indicate a growing mental health care need for depression, particularly among men.