An apparatus for intra-oral stimulation of the trigeminal nerve includes an energy source that imparts energy to a tooth to stimulate the trigeminal nerve and an attachment portion to secure the energy source in a mouth in proximity to the tooth. Stimulating the trigeminal nerve in this manner has been experimentally shown to induce and/or enhance relaxation and/or sleep without the adverse side effects associated with traditional drug therapies. In one embodiment, the apparatus can be realized as a "cap" having two legs that engage opposing sides of a tooth and a bridge portion spanning the occlusal surface of the tooth to link the legs.