Past trends and future projections of psychological distress among general population in Finland.

Introduction: Information on projections of psychological distress is necessary to allocate resources properly for prevention and mental healthcare and treatment. The aim was to examine past and future trends of psychological distress in Finland from 2013 to 2040.

Methods: Seven representative cross-sectional surveys from the years 2013, 2014, 2015, 2018, 2020, 2022 and 2024 (N=199 229, aged 20+ years) were used. Multiple imputation was used in projecting psychological distress (Mental Health Inventory-5, with cut-off value ≤60) up to the year 2040.

Results: The prevalence of psychological distress was slightly declining during the period 2013-2018 for both men and women, ending up around 18% for men and 19% for women. However, after 2018, trends reversed, showing first a steep increase in psychological distress during 2018-2022 in both men and women, after which the increase plateaued, with the prevalence of psychological distress ending up around 25% for men and 27% for women in 2024. Over the 6-year period, the prevalence of psychological distress increased by 9.1% percentage points (pp) among 20-39 years old, 9.8% pp among 40-54 years old and 6.9% pp among 55-64 years old. In older age groups (65-74 and 75 years and older), psychological distress first increased from 2018 to 2020 but then plateaued, especially among the oldest. An increasing trend is projected to continue in the general population and by 2040, the prevalence of psychological distress is projected to end up around 29% for men and 32% for women.

Conclusions: In Finland, the prevalence of psychological distress has increased substantially in the 2020s particularly in working age adults. Mental health needs to be given a priority in all policies to change the future projections.