Addiction is a brain disorder characterized by compulsive engagement in rewarding stimuli despite adverse consequences. A variety of complex neurobiological and psychosocial factors are implicated in the development of addiction. Classic hallmarks of addiction include impaired control over substances or behavior, preoccupation with substance or behavior, and continued use despite consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification (short-term reward), coupled with delayed deleterious effects (long-term costs).