Preious studies hae shown that drug abusers hae lowered leels of the dopamine D2 receptor, which may be linked to the depressie symptoms drug abusers often suffer from .

• 之前的研究已经显示，药物滥用者的多巴胺D2受体水平降低，这可能与药物滥用者遭受抑郁症状痛苦有关。