The findings were published in the July 27 issue of Neurology.
An accompanying editorial notes several weaknesses of the study. For one thing, the results were based on a very small number of cases. Also, those taking the newer drugs with the higher risk of depression may have been more likely to have chronic and severe epilepsy, and these patients are known to have a higher risk of suicide, noted the editorial authors.
The FDA added the suicide warning to epilepsy drugs after an agency review of 199 studies found that patients taking the drugs had about twice the risk of suicidal behavior compared with patients taking a placebo. The absolute risk amounted to about one added case of suicidal thoughts or behaviors for every 500 patients taking the antiepileptic drugs vs. placebo.
Dr. Josemir Sander, co-author of the editorial, said he doubted these new findings would prompt doctors to reconsider what drugs they prescribe. "I think that most physicians will use good sense and see that there are far too many problems with [the study] and not make knee-jerk reactions," said Sander, of the University College London's Institute of Neurology.
One expert agreed that the findings are far from conclusive. "Although some antiepileptic drugs may pose a risk to increasing suicidal behavior, this study does not prove that," said Dr. Orrin Devinsky, director of the New York University Comprehensive Epilepsy Center. "However, it strongly speaks to the need for more information."
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