Epilepsy is not associated with an increased risk of violent crime, new research shows.
The work is another blow to the misconception that people with epilepsy are also violent, and experts said the results should be used to improve public attitudes towards and perceptions of the illness.
The research questions previous expert opinion, which has suggested a causal relationship between epilepsy and violence.
The idea that epilepsy – along with some other neurological disorders – are associated with a risk of violence was widespread in the 19th century.
The researchers, from the University of Oxford, alongside a number of Swedish experts, examined the Swedish population registers between 1973 and 2009 for any associations between epilepsy and convictions for violent crime, which included murder, sexual offences, assault and intimidation.
Among those with epilepsy, 973 (4.2%) committed a violent offence after diagnosis, significantly increased odds compared with population controls.
But this association disappeared when individuals with epilepsy were compared with their unaffected siblings.
The researchers said: “For epilepsy, the findings of an absolute rate of violent crime of 4% and the lack of any association in the sibling control study should be seen in the context of expert opinion in the field that states that the link is strong.
“These findings are also potentially important with respect to the fact that epilepsy remains heavily stigmatised.
“Previous views may have been influenced by high-profile criminal cases of individuals with epilepsy who committed homicide and reports of high prevalence of epilepsy in prisoners, and the latter have not been subsequently confirmed.”
Mike Kerr, professor of learning disability psychiatry at Cardiff University, said: “This is an important, well-conducted study that adds valuable information to diminish one of the unproven stigmas associated with epilepsy.
“The authors show that people with epilepsy are not more prone to commit violent crime when compared with their siblings, though there was a slight increased risk when those with drug addiction were removed and comparison was made with the general population.
“This concurs with clinical evidence that shows that directed violence in a seizure is rare and in the main occurs only when an individual encroaches into the personal space of somebody who is confused during or after a seizure.
“The study should be used to improve public attitudes to people with epilepsy.”
But the research paper, published in the journal PLoS Medicine, found there was a link between traumatic brain injury and violent crime – 8.8% went on to commit a violent crime following their injury.
The researchers added: “As current guidelines for the assessment of brain injury make no recommendations in relation to the assessment or investigation of violence risk, our findings suggest that these may need review, at least for some groups of patients with traumatic head injury, particularly if they abuse illegal drugs or alcohol.
“In prisoners with traumatic head injury, improved screening, assessment, and management may improve repeat offending rate.”
