Addiction is characterized by excessive or compulsive use of rewarding stimuli despite negative consequences. The mechanisms that contribute to addiction are complex and not fully understood. The most widely accepted mechanism involves the reward center of the brain, which is stimulated by neurotransmitters such as dopamine and GABA in response to rewarding stimuli. Genetic, cultural and environmental factors all contribute to the development of an addiction. It is estimated that approximately 10% of the population has an alcohol or drug addiction. A combination of psychotherapy, medication management, and 12-step meetings have shown to be beneficial in achieving and maintaining recovery.