Dr. Spencer Reid : But this sort of strenuous killing could result in fatigue, increase in appetite, and disorientation.
Jennifer Jareau : Like he ran a marathon.
Dr. Spencer Reid : For some, it could also result in convulsive episodes.
Jennifer Jareau : Epilepsy?
Dr. Spencer Reid : Sort of. Oftentimes after you kill, neurons in your brain misfire and you become over stimulated which causes you to start seeing things.