The Iowa Gambling Task and Cambridge Gambling Task have been used to identify differences in decision-making between individuals with substance use problems and controls. In the Iowa Gambling Task, heavy users of cannabis, stimulants, alcohol tend to suboptimally perform as compared to matched controls by failing to update their choice behavior and instead continuing to select disadvantageous decks across the test session.228–230 This pattern of behavior may be linked with insensitivity to the future consequences of disadvantageous choices231, 232 or insensitivity to negative reinforcement.233 Similarly, in the Cambridge Gambling Task, stimulant, alcohol, marijuana and opiate abusers select suboptimal risky bets and had increased deliberation times in some circumstances compared to healthy controls.227, 234, 235
