Addictionis a brain disorder in which the body must have a substance to avoid physical and psychological withdrawal symptoms. People who become addicted to opioids get a feeling of euphoria and relaxation. Opioids are known to be a euphoric producing drug. All drugs of abuse, from nicotine to heroin, cause a powerful spike of dopamine in the brain making it hard for the brain to ignore. Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centers. Dopamine not only contributes to the experience of pleasure, but also plays a role in learning and memory. This allows the body to remember that experience of pleasure and motivates them to repeat the behavior. These are two main components in the transition from liking something to becoming addicted to it.
When used repeatedly, an individual may build a tolerance and no longer get the same "high" or euphoric feeling as they did when they first used. As a result the individual begins to use a larger dose to get the same effect.
An addict is an individual who seeks out a substance or an activity no matter the outcome or consequence. Some consequences could include losing their job, losing friends, or getting in trouble with the law. Addiction can effect anyone regardless of their demographics such as income, age or race.