In this last image, the reward pathway is shown along with several drugs that have addictive potential. Just as heroin or morphine and cocaine activate the reward pathway in the VTA and nucleus accumbens, other drugs such as nicotine and alcohol activate this pathway as well, although sometimes indirectly (point to the globus pallidus, an area activated by alcohol that connects to the reward pathway). Although each drug has a different mechanism of action, each drug increases the activity of the reward pathway by increasing dopamine transmission. Because of the way our brains are designed, and because these drugs activate this particular brain pathway for reward, they have the ability to be abused. Thus, addiction is truly a disease of the brain. As scientists learn more about this disease, they may help to find an effective treatment strategy for the recovering addict.