Meds don't increase suicide risk for epileptics, but may for depressed

Taking antiepileptic drugs does not increase epilepsy patients' risk of suicide, according to a new analysis.

Researchers used a database of 5 million patients in the United Kingdom to assess the risk of attempting or committing suicide. Patients who didn't take antiepileptic drugs and hadn't been diagnosed with epilepsy, depression, or bipolar disorder had a suicide risk of 15.0 per 100,000 patient-years. Epilepsy patients who weren't on the drugs had a rate of 38.2 per 100,000, compared to 48.2 for epileptic patients who did take the drugs. However, once researchers adjusted for age, coexisting conditions and other risk factors, the patients with epilepsy taking drugs were no more likely to have attempted suicide than those who didn't take the medication.

The drugs were not associated with higher risk in bipolar patients, either. But there was a significantly increased risk of suicide in drug-taking patients who had depression or hadn't been diagnosed with epilepsy, depression or bipolar disorder. Researchers noted that at least some of these patients may have been taking the drugs because of pain, and that pain has previously been associated with suicide risk. The cause for the higher risk in depression patients is also uncertain, the study authors said. For example, they speculated that use of the drugs may be a marker of severe depression.

The results conflict with those of an FDA meta-analysis of controlled trials of antiepileptic drugs, the authors noted. Other recent research on the topic has looked at differences in risk among specific antiepileptic medications, but wide confidence intervals prevented this study from coming to precise conclusions on that issue. This study population overall also had a lower than average suicide rate because patients at high risk for suicide, such as those who had a history of attempts, were excluded.

In conclusion, the researchers found no support for an association between antiepileptic drugs and suicide in patients who are taking the medications for epilepsy. They concluded that illness, rather than drug use, is a more important factor in suicide risk. The study was published in the Aug. 5 New England Journal of Medicine.