The Science of Addiction

THE REWARD PATHWAY
Sometimes you may ask yourself, how do I stay full after I've eaten? In the middle of the brain, there sits the reward pathway, which is responsible for feelings of motivation, reward and behavior. The main job of the reward pathway is to make us feel good when we perform behaviors that are necessary for our survival. These behaviors include eating, drinking and sex. The pathway connects to several important ares of the brain. These connections allow the reward pathway to gather information about what is happening outside of the body. Imagine you haven't eaten all day and someone gives you a nice big sandwich. Your senses then gather information about your surroundings and send signals to the brain letting it know that there is a yummy looking sandwich in front of you. After you eat the sammich, memory in another part of your brain is that you have eaten a sandwich, and you will no longer be hungry, so you feel good. When the five senses let the brain know that the body is eating some good tasting food and the stomach is filling up, special neurons in the reward pathway release the chemical dopamine. The release of dopamine gives you a little jolt of pleasure. That's your reward for eating the sandwich.

DRUGS AND THE REWARD PATHWAY
Within seconds of entering the body, drugs cause dramatic changes to synapses in the brain. By bypassing the five senses and directly activating the brain's reward circulatory fast and hard, drugs can cause a jolt of intense pleasure. Drugs affect the brain in such a way that the brain must adapt. One way the brain try to compensate is to reduce the number of dopamine receptors at the synapse. As a result, after the user has "come down", they will need more of the drug next time to reach this high. The faster a rug is delivered to the brain, the more likely it is to be addicting. As the brain continues to adapt to the presence of the drug, regions outside of the reward pathway are affected. Regions responsible for judgement, learning and memory begin to physical change or become "hard-wired." Once this happens drug-seeking behavior becomes driven by habit. This is how a drug user becomes transformed into a drug addict.