Addiction also referred as substance dependence is a chronic, relapsing disease affecting the brain�s reward, motivation, and related systems. People struggling with addiction are unable to control their actions or make rational decisions about their behavior, even in the face of negative consequences.
Compounds and experiences with addictive potential activate the brain�s reward circuitry. These triggers are also called reinforcers because the pleasurable feeling we get from them makes us more likely to engage in them again. Both alcohol and illicit drugs are powerful reinforcers, and cause the release of the neurotransmitter dopamine in the brain�s reward system. Repeated activation by these compounds changes the brain�s reward system structurally and chemically, and produces behaviours like bingeing,escalating use, and symptoms of withdrawal when the drugs are taken away.