Addiction 101
Drugs (incl. alcohol) effect the natural reward system in the brain. They hijack this system and affect communications between different parts of the system.
In a non-addicted individual, normal communication occurs between the limbic system (reward system) and the pre-frontal cortex (decision and reasoning). This communication is necessary for a person to determine if doing something is a good idea. Perceived negative consequences of an action, would result in a decision to stop the action.
Someone struggling with addiction is faced with a communication breakdown between the limbic system and the pre-frontal cortex. The signal to consider consequences to an action is disrupted. The result is a continuation of the act that yields positive rewards, regardless of consequences. As such, individuals struggling with addiction continue their addictive behavior in spite of negative consequences, as the brain considers this to be the right thing to do.
Every drug effects this reward system and most do it by flooding the system with dopamine. Dopamine is a neurotransmitter that is responsible for regulation of movement, emotion, motivation, and pleasure. Without external influences, activating dopamine at natural levels results in a positive feeling and natural behaviors. The problem occurs when drugs cause an overstimulation of the system. High dopamine levels result in a feeling of euphoria. Different drugs affect these levels in different ways. If repeated through continued binge use and abuse, the brain compensates by reducing the natural production of dopamine. This natural reduction leads to the desire to use again as it is difficult to feel anything good without the external use of drugs. Over time, the continued use begins to reinforce this drug use behavior, basically teaching the user to repeat it.
