People with epilepsy are three times more likely to commit suicide than the general population, research suggests.
Seizures can be stigmatising
Danish researchers also found women with epilepsy were more likely to kill themselves than men with the condition.
People diagnosed with epilepsy in the previous six months were at an even higher risk of committing suicide.
The Lancet Neurology study said greater efforts were needed to control seizures, which could be stigmatising, and had many knock-on effects.
The Aarhus University Hospital team studied 21,169 cases of suicide in Denmark between 1981 and 1997.
They found that 492 (2.32%) of the suicide cases had epilepsy. However, the rate of epilepsy among a random matched sample of over 400,000 people in the general population was just 0.74%.
Even after taking account of factors such as mental illness, job status, income and marital status, people with epilepsy were still twice as likely to kill themselves.
And people who had been diagnosed with epilepsy within the previous six months were more than five times more likely to commit suicide.
People with both epilepsy and a psychiatric illness were nearly 14 times more likely to commit suicide than people with neither conditon.
The trend in the general population is for the risk of suicide to increase with age.
But the researchers found that, in the case of people with epilepsy, the risk of suicide fell as they got older.
Big impact on life
Researcher Dr Jakob Christensen said: "There may be a number of factors that have a major impact on the wellbeing of people with chronic disorders such as epilepsy.
"We know that epilepsy lowers the overall quality of life of the affected individuals - especially shortly after the diagnosis is given.
"An epilepsy diagnosis affects important parts of people's lives: job opportunities disappear, patients usually lose their driver's licence, drug treatment may decrease fertility, and pregnancy is associated with an increased risk of congenital malformations of the newborn child.
"The latter may be part of the explanation of why the impact of epilepsy with regard to suicide seems greatest in women."
Dr Christensen added that having seizures could be a very unpleasant and stigmatising experience.
He said; "Epilepsy is not a rare disorder, affecting up to 1% of the population.
"Thus, great efforts should be put into reducing the risk of seizures in patients."
The charity Epilepsy Action said the figures emphasised the impact that epilepsy could have on a person's life.
It is campaigning for better epilepsy services to speed up diagnosis and treatment of the condition.
With the right anti-epileptic drugs, an estimated 70% of people can be kept free of seizures.
A report by MPs published last month suggested almost half of the 990 epilepsy-linked deaths in England each year were avoidable.
However, Professor Ley Sander, of the National Society for Epilepsy, said: "It is almost certainly true that people with epilepsy are at greater risk of committing suicide than people without but why that should be is not clear from this study."