The effect of lacosamide on psychiatric comorbidities in patients with epilepsy

We investigated the efficacy of lacosamide (LCM) polytherapy in improving seizure outcomes and psychiatric symptoms in patients with epilepsy with psychiatric comorbidities. We retrospectively collected data from medical records of outpatients of the Department of Psychiatry of Nishiniigata Chuo Hospital Epilepsy Center in Japan. We extracted data from all patients with epilepsy and psychiatric comorbidities who had been treated with LCM. We evaluated seizure prognosis and changes in psychiatric symptoms after LCM polytherapy. After LCM administration, 19 (47.5%) patients had improvements in seizure outcomes. The other 18 (45%) patients experienced no changes in seizure outcomes, and the remaining 3 (7.5%) patients experienced worse seizure outcomes after LCM polytherapy. LCM administration improved psychiatric symptoms in 21 (52.5%) of the 40 patients; psychiatric symptoms did not change in 14 (35%) patients and worsened in 5 patients (12.5%). There was no significant association between psychiatric and seizure prognoses. LCM polytherapy may have less negative influence on psychiatric comorbidities in patients with epilepsy compared with other antiseizure medications, and may also improve seizure severity. While LCM polytherapy might improve psychiatric symptoms as seizures improve, a small number of patients experienced worsening of psychiatric symptoms despite seizure improvement.