A stimulation device is used to entrain a target neural rhythm of a subject for treatment of the neurological disorder. A stimulation circuit generates a stimulation signal that is periodic and has stimulation periods that are dithered with an average period corresponding to an entrainment frequency of the target neural rhythm. As a result of the dither, neural stimulation using the stimulation signal causes entrainment of the target neural rhythm at the entrainment frequency and minimising entrainment of other neural rhythms at integer ratios of the entrainment frequency that may otherwise cause harmful effects.