Claims have been made that epilepsy is associated with both brief
psychotic episodes and persistent psychotic states. The existence of brief,
nonconfusional psychotic episodes in epilepsy has received some formal
support; these may be a function of temporal lobe subictal activity.
Persistent psychosis is found in about 7% of patients with epilepsy;
independent evidence indicates this to be a significant association.
Temporal lobe seizure activity, again probably acting subictally, may be
involved in the pathogenesis of these states, perhaps in interaction with
other factors. Occurrence of psychotic syndromes in epilepsy may be
relevant to kindling, atypical psychoses unrelated to epilepsy, and the
psychotropic effect of carbamazepine.