Epilepsy, personality, behavior and psychopathology--the state of the evidence and directions for future research and treatment.

Nearly 100 years ago, John Hughlings Jackson defined epilepsy as “excessive neuronal discharge.” This definition has not been surpassed to this day. What we have learned since Jackson’s time is that rapid neuronal discharge is part of the brain’s normal repertoire and that it is the excessive propagation and synchrony of such excessive neuronal discharge that constitutes epilepsy. In this discussion I should like to focus on the role of natural or normal episodic “excessive neuronal discharge” and the processes that foster or inhibit propagation and synchrony of excessive neuronal discharges from their natural and unnatural sources (Table 1 ) . The relationship between epilepsy and psychopathology has long interested both neurologists and psychiatrists and culminated