Some have characterized dopamine as the elixir of pleasure because so many rewarding stimuli - food, drugs, sex, exercise - trigger its release in the brain. However, more than a decade of research indicates that when drug use becomes compulsive, the related dopamine release becomes deficient in the striatum, a brain region that is involved in reward and behavioral control. New research suggests that dopamine release is increased in obsessive-compulsive disorder and may be normalized by the therapeutic application of deep brain stimulation.