Methods of stimulating a vagus nerve include providing at least one implantable stimulator with at least two electrodes, configuring the electrodes to apply stimulation that unidirectionally propagates action potentials along a vagus nerve, and applying the stimulation to the vagus nerve to effectively select afferent fibers, thereby treating at least one of epilepsy and depression while limiting side effects of bidirectional stimulation. At least one of the electrodes comprises a leadsless electrode.