Increased frequency of psychosis after second-generation antiepileptic drug administration in adults with focal epilepsy.

Many studies show psychoses after some antiepileptic drug (AED) administrations (post-AED administration psychoses [PAP]). It remains uncertain about psychogenetic potential of each AED and effects of clinical state factors on PAP. We examined the relations between AED-related factors (types, generations, dosages, and concomitant AED) and PAP. The clinical records of patients with focal epilepsy were retrospectively reviewed from eight adult epilepsy clinics, for every six-month period after administration of a new drug (either AED or non-AED) between 1981 and 2015. Characteristics of psychotic episodes, AED-related factors (type, daily dosage, and concomitant AED), and other state-related risk factors to psychosis (age, duration of epilepsy, history of psychosis, and seizure frequency) were examined. Psychogenetic risks of AED-related and state-related factors were analyzed with multifactorial procedures. Of 2067 patients with focal epilepsy, 5018 new drugs (4402 AEDs and 616 non-AEDs) were administered. Within the first six-month period, 89 patients exhibited 105 psychotic episodes (81 interictal and 24 postictal psychoses: 55 first episodes and 50 recurrences). With second-generation AED (SAED) administration, particularly topiramate and lamotrigine, frequency of psychosis was significantly increased. Daily dosage of AED was not significantly associated with psychosis. Psychosis tended to occur with a higher number of concomitant AED. Subsequent analysis with AED-related and general factors showed that SAED administrations and previous psychotic history were the most significant risks for PAP. Post-AED administration psychoses is associated with type of AED (SAED), rather than its dosage. Individual vulnerabilities are also associated with PAP.