Dopamine plays an important role in controlling movement, emotion and cognition.
Dopaminergic dysfunction has been implicated in the pathophysiology of schizophrenia, mood disorders, attention-deficit disorder, Tourette's syndrome, substance dependency, tardive dyskinesia, Parkinson's disease and other disorders. They initiated an important advance in the treatment of schizophrenia without a clear understanding of the mechanisms underlying the drug ' s therapeutic effect. In 1963, Carlsson first postulated that the effects of neuroleptics were secondary to dopamine receptor blockade. Also at this time researchers discovered that dopamine depletion in the striatum played a role in Parkinson's disease. In 1979, Kebabian and Calne determined that at least two dopamine receptors mediated this system, and for the next decade the actions of dopamine were viewed as being mediated by two dopamine receptors, D1 and D2.