Brain diseases such as depression, dementia, and sleep disorders are far more prevalent than many believe

According to a large new Danish study from Aarhus University and Aarhus University Hospital, a total of 35.2 percent of the population lives with a brain disease—an increase from 2015 when the figure was 33.2 percent.

But why are we seeing this increase? According to the lead author of the study, Cecilia Hvitfeldt Fuglsang, PhD at the Department of Clinical Medicine and a physician at Aarhus University Hospital, one of the reasons could be that Danes are living longer—and thus longer with their diseases.

“Changes in the population’s age distribution and greater awareness of mental disorders likely contribute to the increase. At the same time, the COVID-19 pandemic may have led to fewer diagnosed cases, as access to the healthcare system was limited,” she explains.

Mortality rate remains unchanged

The study shows that individuals with brain diseases have a fivefold higher risk of dying within a year compared to individuals without brain diseases.

The high mortality rate has not changed since 2011, despite improved treatments for certain brain diseases.

“We had expected the excess mortality to decrease. Unfortunately, it has remained unchanged,” says Cecilia Hvitfeldt Fuglsang.

Healthcare costs rise significantly

Individuals with brain diseases impose a heavy economic burden on society. In 2021, the indirect costs—such as lost labor—amounted to 173 billion DKK, representing a 31 percent increase since 2015.

“One reason could be that real wages have increased. So when people are absent from the workforce due to illness, the financial impact is larger,” explains Cecilia Hvitfeldt Fuglsang.

The study’s findings emphasize that brain diseases are not only a challenge for those affected but also a significant economic burden on society.

According to the researchers behind the study, increased awareness and a better understanding of brain diseases could help reduce both the disease burden and the stigma that still surrounds many brain diseases.

“We hope our findings will create greater awareness and understanding of brain diseases and their consequences for both society and the people living with them,” says Cecilia Hvitfeldt Fuglsang.

Facts about brain diseases

Brain diseases include both neurological and psychiatric disorders. Some of the most common brain diseases are:

• Depression (affects 13.5 percent of Danes)

• Sleep disorders (affects 13.5 percent of Danes)

• Dementia

• Stroke (blood clot or bleeding in the brain)

• Neurodegenerative disorders

About the research - more information

Study type: Cohort study based on data from national registries.

Collaborators: Department of Clinical Epidemiology, Aarhus University Hospital; Department of Economics, Aarhus University, EY Denmark.

External funding: Lundbeck Foundation

Conflicts of interest: Stated in the “Declaration of Interests” section in the scientific article.

Link to the scientific article: https://doi.org/10.1016/j.lanepe.2024.101189

Contact 

PhD and MD Cecilia Hvitfeldt Fuglsang
Aarhus University, Department of Clinical Medicine
Aarhus University Hospital, Department of Clinical Epidemiology
Email: chfn@clin.au.dk
Phone: +45 87168486

Professor and consultant Christian Fynbo Christiansen
Aarhus University, Department of Clinical Medicine
Aarhus Universitety Hospital, Klinisk Epidemiologisk Afdeling
cfc@clin.au.dk
Phone: +45 87168218