SAN DIEGO—Selective serotonin reuptake inhibitor (SSRI) and serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressants did not increase seizure frequency in a retrospective series of epilepsy patients, as reported at the 64th Annual Meeting of the American Epilepsy Society.
The researchers investigated how 84 adult patients with epilepsy fared after taking the drugs for six months. None of the patients had an increase—and some actually had a decrease—in seizure frequency, and almost all had improvements in their baseline depression and anxiety.
“There’s a long-held misconception that antidepressants have proconvulsive properties,” probably because a few older tricyclic antidepressants and bupropion do, said lead investigator Ramses Ribot, MD, a neurophysiology fellow at Rush University in Chicago.
That concern has carried over to SSRIs and SNRIs, for which there is no evidence of a proconvulsive effect. As a result, neurologists “are very hesitant to” prescribe the newer agents to epilepsy patients, and depression and anxiety, both common in epilepsy, remain “definitely undertreated,” said Dr. Ribot.
Seventy-nine patients in the study were taking SSRIs, most commonly escitalopram; the remaining five were taking SNRIs. Among the 44 patients who entered the study with fewer than one seizure per month, seizure frequency did not change during antidepressant therapy.
Among the 40 patients who entered with one to 12 seizures per month, seizure frequency was reduced to fewer than one per month in 11 (27.5%) and did not change in 27 (68%). Seizures increased from one per month to two or three in two patients. Overall, 16 (40%) of the 40 patients had a greater than 50% reduction in seizure frequency.
The findings suggest that “these medications could have an anticonvulsant effect”—something that’s been suggested in previous research as well, Dr. Ribot said.
Sixty-one of the 71 patients (86%) for whom psychiatric evaluations were available had improvements or remissions of depression and anxiety symptoms while on antidepressants, a finding that appeared to be independent of seizure frequency.
No procedural interventions or changes to antiepileptic drug regimens were observed during the study and in the three months leading up to it. The patients were older than 18 and were clinically diagnosed with depression or anxiety disorders at baseline.
—M. Alexander Otto