1. A method for delivering a vagal stimulation therapy to a vagus nerve, comprising: stimulating the vagus nerve, wherein stimulating the vagus nerve includes simultaneously stimulating both afferent axons and efferent axons in the vagus nerve; and avoiding physiological habituation to stimulating the vagus nerve, wherein avoiding physiological habituation includes scheduling stimulation of the vagus nerve to provide a stimulation schedule using a programmable value for a therapy duration to control a therapy period or a programmable value for an intermittent neural stimulation parameter associated with on/off timing for stimulating the vagus nerve, wherein stimulating the vagus nerve includes stimulating the vagus nerve according to the stimulation schedule.