Addiction is a complex condition, a brain disease that is manifested by compulsive substance use despite harmful consequence. People with addiction (severe substance use disorder) have an intense focus on using a certain substance(s), such as alcohol or drugs, to the point that it takes over their life. They keep using alcohol or a drug even when they know it will causes problems. Yet a number of effective treatments are available and people can recover from addiction and lead normal, productive lives.
People with a substance use disorder have distorted thinking, behavior and body functions. Changes in the brain’s wiring are what cause people to have intense cravings for the drug and make it hard to stop using the drug. Brain imaging studies show changes in the areas of the brain that relate to judgment, decision making, learning, memory and behavior control.
These substances can cause harmful changes in how the brain functions. These changes can last long after the immediate effects of the drug — the intoxication. Intoxication is the intense pleasure, calm, increased senses or a high caused by the drug. Intoxication symptoms are different for each substance.
Over time people with addiction build up a tolerance, meaning they need larger amounts to feel the effects.