 All addictive drugs directly or indirectly affect dopamine neurotransmission in the nucleus accumbens; these drugs increase drug "wanting", leading to compulsive drug use, when repeatedly taken in high doses, presumably through the sensitization of incentive-salience.Drugs that increase synaptic dopamine concentrations include psychostimulants such as methamphetamine and cocaine.These produce increases in "wanting" behaviors, but do not greatly alter expressions of pleasure or change levels of satiation.