Chronic drug use causes sustained activation of CREB, which enhances expression of its target genes, some of which code for proteins that then dampen the reward circuitry.

• 药物长期使用会造成CREB的持续活化，因而加强CREB目标基因的表现，其中有些基因制造出来的蛋白质会抑制报偿线路。