MONDAY, Oct. 10, 2005 (HealthDay News) -- The same brain dysfunction that underlies epilepsy may also influence suicide risk, researchers report.
The study findings also suggest that suicide and depression may have different brain mechanisms.
"For reasons that are not understood, depression both increases the risk for developing epilepsy and is also common among people with epilepsy who experience many seizures," lead researcher Dale C. Hesdorffer of Columbia University, New York City, said in a prepared statement.
"One question we had was whether some symptoms of depression were more important than others for increasing the risk for developing epilepsy. Suicidal thoughts and suicide attempt were possibilities, because people with epilepsy seem to be more likely to commit suicide than the general population. But we looked at all symptoms of depression," Hesdorffer said.
Published online October 10 in the journal Annals of Neurology, the study included 324 people with epilepsy and 647 people without the disorder. The researchers found that a history of depression was associated with an increase in the risk of epilepsy.
They were also surprised to find that people with epilepsy were four times more likely to have attempted suicide before ever having an epileptic seizure. This was true even after the researchers accounted for other factors such as alcohol consumption, age, gender and depression.
The researchers also found that the presence of specific depression symptoms didn't predict a greater likelihood of later epileptic seizures.
The findings suggest that there's a common underlying brain mechanism for epilepsy and suicidal behavior and that depression and suicidal behavior may be related to different brain mechanisms, the study authors wrote.
"Increasingly, clinicians treating people with epilepsy ask about current depression, but they may not ask about past suicide attempt or suicidal thoughts," Hesdorffer said. "Our results may alert clinicians to the need to ask this question and offer any needed counseling to prevent the occurrence of later completed suicide."
The Epilepsy Foundation has more about epilepsy and depression.