BOSTON (Reuters) - Some seizure drugs may not raise the risk of suicide for patients with epilepsy as feared, but they do increase the risk for people with depression, researchers reported this week in the New England Journal of Medicine.

They say the drugs do not make it more likely that patients with epilepsy will commit suicide. But people take the drugs for a range of other conditions and some of these had a 65 percent higher risk.

In 2008 the U.S. Food and Drug Administration warned that epilepsy drugs may increase the risk of suicide.

The new study, led by Dr. Alejandro Arana of Risk MR Pharmacovigilance Services in Zaragoza, Spain, culled records from more than 5 million patients in Britain treated from 1988 to 2008. During this time there were 8,212 suicide attempts.

The researchers found that people with epilepsy, depression, or bipolar disorder who were not taking epilepsy drugs had a higher likelihood of suicide attempts in the first place.

The authors noted that individuals without epilepsy, depression, bipolar disorder, or anticonvulsant drug treatment had a suicide incidence rate of 15.0 per 100,000 persons per year. This rate rose to 38.2 among patients with epilepsy who did not receive antiepileptic drugs, and 48.2 among patients with epilepsy who received antiepileptic drugs.

But after accounting for other relevant factors, taking one of the antiseizure drugs did not increase the risk of suicide for people with epilepsy or bipolar disorder, or among patients whose epilepsy was combined with depression.

However, the anticonvulsants were significantly associated with a 65 percent increased suicide risk among patients with depression and a greater than twofold increased risk for those who did not have epilepsy, depression, or bipolar disorder.

"In general, our results do not confirm the findings previously reported by the FDA," the research team concluded.

Last week a separate group of researchers, who also studied British patients, concluded that attempted suicide or self-harm only occurred in epilepsy patients taking newer drugs that have been linked to a risk of depression.

That study, in the journal Neurology, tracked 453 suicide attempts or incidents of self-harm, a small fraction of the number in Dr. Arana's survey.

SOURCE: http://link.reuters.com/jap53n

New England Journal of Medicine, August 5, 2010.