Occurrence, mortality, and economic burden of brain disorders in Denmark, 2015-2021: a population-based cohort study

Lancet Reg Health Eur. 2024 Dec 19:50:101189. doi: 10.1016/j.lanepe.2024.101189. eCollection 2025 Mar.

Abstract

Background: Brain disorders (neurological and mental disorders) are common and burdensome diseases. We examined occurrence, mortality, and economic burden of brain disorders in Denmark from 2015 to 2021.

Methods: We conducted a nationwide population-based cohort study using individual-level registry data. We computed the prevalence of any brain disorder and 25 individual brain disorders for each year from 2015 to 2021 and incidence for 2011-2015 and 2016-2021. We computed one-year hazard ratios (HRs) for all-cause mortality by comparing individuals with brain disorders to matched controls without and calculated attributable direct and indirect costs (i.e., economic burden) of brain disorders.

Findings: The prevalence of any brain disorder in Denmark was 1,893,318/5,705,540 = 33.2% in 2015, increasing to 2,059,852/5,856,666 = 35.2% in 2021. The most prevalent conditions were depression (793,419/5,856,666 = 13.5% in 2021), sleep disorders (788,209/5,856,666 = 13.5% in 2021), and headache (461,353/5,856,666 = 7.9% in 2021). The incidence rate of any brain disorder was 1792 and 1634 per 100,000 person-years in 2011-2015 and 2016-2021, respectively. The one-year HR of mortality for any brain disorder was 5.5 (95% confidence interval [CI]: 5.4; 5.6) for 2011-2015 and 5.3 (95% CI: 5.2; 5.3) for 2016-2021. The total attributable direct costs for individuals with any brain disorder were €7.5 billion in both 2015 and 2021. Total indirect costs increased from €17.7 billion in 2015 to €23.2 billion in 2021.

Interpretation: Brain disorders remain common, with a fivefold higher one-year mortality compared to persons without brain disorders. While total direct costs were similar in 2015 and 2021, total indirect costs increased over this period.

Funding: The Lundbeck Foundation (R433-2023-1140).

Keywords: Epidemiology; Health economics; Neurology; Psychiatry.