Psychoses after an antiepileptic drug administration: Frequency, timing, and duration

To clarify the pathophysiology of psychoses after the new administration of antiepileptic drugs (AED), we analyzed the annual incidence, timing of development, and duration of episodes.

Psychotic outcomes in the first 6-month period after an AED or non-AED administration in patients with focal epilepsy were exhaustively reviewed in eight Japanese neuropsychiatry institutions. In cases with psychotic episodes, the subtype of psychosis, timing of development, previous history of psychosis, and duration of the episode were evaluated.

Between 1981 and 2015, 5018 new drugs (4402 AED and 616 non-AED) were administered to 2067 patients with focal epilepsy. In the first 6-month period, 105 psychotic episodes occurred (81 interictal psychosis [IIP] and 24 postictal psychosis). Furthermore, 55 cases were first episodes and 50 were recurrent episodes. The frequency of psychoses is significantly higher after AED administration (n = 102) compared with non-AED administration (n = 3). Psychosis occurred most frequently in the initial 1-month period after new-AED administration and tended to decrease with increasing time. The estimated annual incidence of all psychoses after a new AED administration was 3.5% (2.0% for first-episode psychosis and 1.8% for first-episode IIP). Duration of psychoses (mean, 38.5 weeks) was equivalent to overall IIP. Duration of IIP did not shorten with discontinuation of newly administered AED.

Patients with epilepsy exhibit psychosis more frequently after new AED administration than after non-AED administration. This study shows the pathophysiology of psychoses after AED administration with annual incidence, the timing of development, and the duration of PAP, which have rarely been reported.