Social determinants of mental disorders in Finland - a register-based study

Last updated: 05.08.2025

Aims

This project aims to:

  • update key descriptive analyses of the epidemiology of mental disorders in Finland, incorporating both primary and secondary care data;
  • examine the dynamic interplay between socioeconomic factors and mental health across the life course and on multiple levels; and
  • improve the conditions and methodologies of register-based research by applying principles of open science.

Rationale

Although analytical epidemiology has advanced our understanding of mental disorders, descriptive analysis remains essential for capturing the broader landscape of psychiatry and mental health. Trends such as deinstitutionalization, evolving public attitudes, the integration of mental health into primary care, and socio-political changes highlight the need for regularly updated descriptive data and continuous monitoring.

These efforts are crucial not only for informing clinicians and the public but also for fostering evidence-based discussions about best practices in mental health care.

Depression and anxiety are among the ten most common reasons for visits to primary care in Finland. Yet, much of the existing register-based research focuses exclusively on secondary care. This project seeks to address this gap by analyzing both primary and secondary mental health service use.

So far, this project has focused on several classical questions in psychiatric epidemiology:

Topics

Household income and the incidence of first psychiatric hospital admissions

This study is among the few that report incidence rates for all first psychiatric hospital admissions. To the best of our knowledge, it is also the first national-level study to demonstrate a clear income gradient in the incidence of first hospitalizations due to mental disorders. Household income emerged as a significant risk factor across the entire income distribution.

In Finland, between 1994 and 2014, the age-standardized annual incidence rate of first psychiatric hospital admissions peaked in 2008 and declined thereafter.

Following this study, two other Finnish publications reported similar trends, including increases in first admissions among adolescents and among children, adolescents, and young adults. These findings are particularly noteworthy in the context of a health care system increasingly oriented toward outpatient care. The observed increase in first hospitalizations raises concerns about the effectiveness of outpatient services in preventing or managing acute and severe mental health crises. #### Awards

This study won the Publication of the Year by Finnish Psychiatric Association in 2020 and the Research Prize by the European Psychiatric Association (EPA) in 2021 awards.

References

  • Suokas K, Koivisto AM, Hakulinen C, Kaltiala R, Sund R, Lumme S, Kampman O, Pirkola S. Association of Income With the Incidence Rates of First Psychiatric Hospital Admissions in Finland, 1996-2014. JAMA Psychiatry. 2020;77(3):274. doi:10.1001/jamapsychiatry.2019.3647 link

Media (mainly in Finnish)

Regional and urban-rural variations in the prevalence of mental disorders

In Finland, the prevalence of schizophrenia has traditionally been higher in the eastern and northern regions, mirroring the distribution of schizophrenia polygenic risk scores. Both genetic and environmental factors have been suggested as contributors to this regional variation, which aligns with a well-established east–west gradient in population health and genetic structure.

However, in our study, after adjusting for socioeconomic and sociodemographic factors, this east–west pattern in the prevalence of mental disorders largely disappeared. In contrast, urban–rural differences remained robust, even after adjustment.

References

  • Suokas K, Kurkela O, Nevalainen J, Suvisaari J, Hakulinen C, Kampman O, Pirkola S. Geographical variation in treated psychotic and other mental disorders in Finland by region and urbanicity. Social Psychiatry and Psychiatric Epidemiology. 2023;59(1):37-49. doi:10.1007/s00127-023-02516-x link

Media

Data and methodology

National registers from TRIAD: The unhappy triad - Mental disorders, somatic illness and socioeconomic deprivation in different phases of life - project have been used.

Pre-processing of the register: Identifying treamtment episodes

The scripts called hilmo_identify_episodes have been made publicly available in order to enable others to evaluate and benefit from this effort. We call for open science principles and collaborative development of readily available methods for saving researchers’ time and enhancing research quality by improving comparability and reproducibility of results.

In this study, we showed that registers with continuous and mainly automatized data collection, such as the Finnish healthcare registers, contain partly overlapping register entries and preliminary diagnoses. The methods employed in pre-processing register data significantly impact the metrics derived from the registers. Regarding lifetime incidence of mental disorders, schizophrenia spectrum disorders require a particular focus on data pre-processing.

References:

My PhD thesis

Link to the thesis document.

The thesis was granted the Martti Kaila Award for an Outstanding Doctoral Dissertation 2024 by the Finnish Psychiatric Association (link) and and received a University of Tampere Foundation Grant for a doctoral dissertation accepted with distinction.

Media