Dopamine and food reward: back to the elements

Abstract
The brain mechanisms by which animals forage for and consume food are, in all likelihood, the brain mechanisms that are involved in the foraging for and use of addictive drugs. It is well established that brain dopamine is important for the rewarding effects of amphetamine, cocaine, opiates, and several other (but not all) drugs of abuse. Dopamine levels are elevated not only by most drugs of abuse but also by natural rewards such as food or sexual contact. If the dopamine system is blocked, animals do not learn to lever press for these normally habit-forming substances. If the dopamine system is blocked, animals that have already been trained to lever press for food, amphetamine, or cocaine do not continue to do so.