Natalie Angiers in the New York Times discusses in a trenchant and amusing fashion how dopamine is essential to motivate us to action. She neglects to point out that serotonin is the neurotransmitter that tells us when to stop. Jonah Lehrer complements her article on the Frontal Cortex website.
Here are my comments:
The addicted patient seeks dopamine not only to give pleasure but to relieve the pain of dopamine deficit. Unfortunately, increasing dopamine can itself be addictive or as Richard Pryor put it, "Cocaine makes a new man out of me and the new man wants cocaine." Fortunately, actually inevitably, there is a neurotransmitter that inhibits behavior, serotonin.
In 1993, I introduced Dr. Richard Rothman, director of National Institute of Addiction's Intramural Research Program in Baltimore, to the idea that combined dopamine and serotonin agonists
(CODAS) could treat addiction and other disorders. I have gone on and used levodopa and 5-HTP the precursors of dopamine and serotonin, as the best way to manage same. Richard has gone in another direction. In this recent article he reviews the rationale behind CODAS and the dual deficit model of addiction and discusses the development of an agent that can do this effectively.