What role does CREB play in drug addiction? O It activates dynorphin, which causes the pleasurable aspect of the drug to decline. This can cause a person to increase the dose of a drug. O It makes the nucleus accumbens hypersensitive to the pleasurable aspects of the drug. This increased pleasure is highly motivating. O It facilitates long-term sensitization to the drug and stimuli associated with the drug. This keeps the person craving the drug for a long time. It helps people get off addiction or can prevent addiction in the first place. People with high levels of CREB tend not to develop addictions.