People taking antidepressant medication are at greater risk of developing epilepsy after a major head injury. This is the result of a large study based on data from over 200,000 Danes.

Concussions and more severe traumatic brain injuries are often associated with long-term symptoms such as fatigue, headache and difficulties concentrating, but one of the most serious consequences of head injuries is the development of epilepsy.

A group of researchers from Aarhus University Hospital, Aarhus University, the United States and Australia has investigated whether there is a particularly strong correlation between head injuries and epilepsy among persons already taking antidepressant medication. The result has just been published in the international scientific journal PLOS ONE.

In the study, the researchers analyzed data from just over 200,000 Danes, who in the period 1996 to 2013 suffered a head injury, and compared the risk of epilepsy in persons stratified on whether they were taking antidepressant medication at the time of the injury.

- The results showed that the risk of developing epilepsy was almost twice as great if you took antidepressant medicine when you got the head injury, says Jakob Christensen, consultant at Department of Neurology at Aarhus University Hospital and Institute of Clinical Medicine, Aarhus University.

- The higher risk of epilepsy can be either due to the antidepressant medicine or due to the underlying disease such as depression and anxiety. Further research is needed to clarify whether it is the antidepressant drug or the underlying disease. However, animal testing has shown that the most commonly used antidepressants may be associated with an increased risk of developing epilepsy following a brain injury.

Prevention and treatment in the future

Worldwide traumatic brain injury is one of the leading causes of epilepsy.

- The study has several perspectives for people with traumatic brain injury. The results could potentially help identify people at risk of developing epilepsy after head trauma, and help develop treatment that can prevent epilepsy.


Behind the research result:

Type of study: Cohort study. Register study based on Danish health registers.

Collaboration partners: Aarhus University Hospital, Aarhus University, University of Washington (USA), University of Melbourne, Monash University and The Alfred Hospital (all Australia).

External funding: Novo Nordisk Foundation, Central Denmark Region, Lundbeck Foundation and Epilepsy Society.

Publication: Published in PLOS ONE, which is a peer-reviewed scientific journal.

Conflicts of interest: Jakob Christensen has received fees from UCB Nordic and Eisai AB (pharmaceutical companies) as a scientific advisor, and has received fees from UCB Nordic and Eisai AB for lectures as well as receiving funding for a journey from UCB Nordic. The other authors have no conflicts of interest.


Read the scientific article:

Jakob Christensen, Henrik Schou Pedersen, Morten Fenger-Grøn, Jesse R. Fann, Nigel C. Jones, Mogens Vestergaard:

Selective serotonin reuptake inhibitors and risk of epilepsy after traumatic brain injury - a population based cohort study

Published in PLOS ONE:


More information:

Jakob Christensen, consultant, PhD, MD, Clinical Associate Professor, Department of Neurology, Aarhus University Hospital, and Department of Clinical Medicine, Aarhus University, mobile +45 60 86 58 99, e-mail: