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

Last updated: 05.05.2025

Aims

This project aims

  • to update some fundamental descriptive analysis of the epidemiology of mental disorders in Finland, including primary and secondary care data
  • to analyze the dynamic interplay between socioeconomic factors and mental health over the life-course and on multiple levels, and
  • to improve conditions and methodologies in register-based research by adopting principles of open science.

Rationale

Despite the advancements made in analytical epidemiology concerning mental disorders, the role of descriptive analysis remains important for comprehending the landscape of psychiatry and mental health. Trends such as deinstitutionalization, changes in attitudes towards mental disorders, the integration of mental health into primary care, and economical and political transformations all underscore the need for continuously updated descriptive statistics and monitoring. These efforts serve not only to enlighten both the public and clinicians but also to facilitate informed dialogues on optimal practices.

Depression and anxiety are among the top 10 most common reasons for visits to primary care, but much of the register-based research has been conducted using secondary care data only. Our aim is to expand our analysis to include primary care as well as secondary care mental health services.

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

Topics

Household income and the incidence of first psychiatric hospital admissions

This study is one of only a few studies reporting incidence rates in all first psychiatric admissions, and to the best of our knowledge, it is the first national-level study showing that a robust income gradient is present in the incidence rates of first hospitalizations due to mental disorders. Household income appears to be an important risk factor for first hospital-treated mental disorders at all levels of income.

Between 1994 and 2014 in Finland, the age-standardized annual incidence rate of first hospital admissions peaked in 2008 and subsequently began to decline. Following this study, two other Finnish papers have reported similar findings of increasing first admissions among adolescents and in children, adolescents and young adults. The observed increase in first admissions during a time when outpatient-centered services dominate, raises some concerns about the effectiveness of outpatient care in managing acute and severe mental disturbances.

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, prevalence of schizophrenia is higher in the eastern and northern regions and co-occurs with the distribution of schizophrenia polygenic risk scores. Both genetic and environmental factors have been hypothesized to contribute to this variation. There are well-known differences in population health and genetics that follow a distinct east-west gradient.

We showed, however, that after adjusting for socioeconomic and sociodemographic factors, the within-country distribution of mental disorders no longer followed the traditional east–west gradient. Urban–rural differences, on the other hand, persisted after the adjustments.

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 2025 by the Finnish Psychiatric Association (link) and and received a University of Tampere Foundation Grant for a doctoral dissertation accepted with distinction.

Media