Synonyms for Compulsion (same or very similar meaning)
WordNet sense 1 (an irrational motive for performing trivial or repetitive actions against your will):
obsessionWordNet sense 2 (an urge to do or say something that might be better left undone or unsaid):
irresistible impulseWordNet sense 3 (using force to cause something):
coercionFrom the ODE community, based on WordNetadd/edit