Compounds, compositions and methods for treating drug addiction, nicotine addiction, and/or obesity are disclosed. The compounds are N-aryl diazaspirocyclic compounds, bridged analogs of N-heteraryl diazaspirocyclic compounds, or prodrugs or metabolites of these compounds. The aryl group can be a five- or six-membered heterocyclic ring (heteroaryl). The compounds are effective at inhibiting dopamine production and/or secretion, and accordingly are effective at inhibiting the physiological 'reward' process that is associated with ingestion of nicotine and/or illicit drugs. The compounds and compositions can be administered in effective amounts to inhibit dopamine release, wihout resulting in appreciable adverse side effects (e.g., side effects such as significant increases in blood pressure and heart rate, significant negative effects upon the gastro-intestinal tract, and significant effects upon skeletal muscle).