Addiction is a complex disorder characterized by compulsive drug use. While each drug produces different physical effects, all abused substances share one thing in common: repeated use can alter the way the brain looks and functions. Taking a recreational drug causes a surge in levels of dopamine in your brain, which trigger feelings of pleasure. Your brain remembers these feelings and wants them repeated. If you become addicted, the substance takes on the same significance as other survival behaviors, such as eating and drinking. Changes in your brain interfere with your ability to think clearly, exercise good judgment, control your behavior, and feel normal without drugs. Whether you’re addicted to inhalants, heroin, Xanax, speed, or Vicodin, the uncontrollable craving to use grows more important than anything else, including family, friends, career, and even your own health and happiness. The urge to use is so strong that your mind finds many ways to deny or rationalize the addiction. You may drastically underestimate the quantity of drugs you’re taking, how much it impacts your life, and the level of control you have over your drug use.