response

Drugs are made up of chemicals, many of which are similar to those found in our bodies. Drugs alter the normal transmission, reception, and processing of information by nerve cells. They accomplish this by mimicking the brain’s natural chemical messengers, overstimulating the brain’s “reward circuit,” flooding the brain with excess chemicals, and binding to brain receptors. Almost all drugs target the brain’s reward system, either directly or indirectly. The drugs produce euphoric effects due to the overstimulation of this system, which normally responds to natural behaviors linked to survival like eating, spending time with loved ones, etc.. This reaction starts a cycle in which some people are compelled to repeat the behavior or abuse more drugs. The brain adapts to the overwhelming surges in dopamine by producing less of its own dopamine or reducing the number of dopamine receptors in the reward circuit as a person continues to abuse drugs. As a result, dopamine’s influence on the reward circuit is reduced, limiting the abuser’s ability to enjoy the drugs and other previously pleasurable activities. This decrease drives drug addicts to continue abusing drugs in an attempt to restore normal dopamine function. They may also require more of the drug than they did at first to achieve the same high—this effect is known as tolerance. Long-term abuse also affects other chemical systems and circuits in the brain. Drugs of abuse facilitate nonconscious learning, leading to virtually uncontrollable cravings when the user sees a place or a person associated with the drug experience, even if the drug is not available, almost like helluscinating. A drug addicts’ brain has changes in areas of the brain that are important for judgment, decision-making, learning and memory, and behavior control. These changes, when combined, can lead to an abuser seeking out and taking drugs compulsively, despite negative consequences—in other words, to become addicted to drugs.