The picture emerging from psychology labs is that there is at most a kernel of truth in this stereotype, while some studies find no evidence of even subtle mental impairment in heavy users.

• 心理学实验室发现，这种老生常谈式的说法最多只有一小部分是对的，而一些研究发现在大量吸食的人群中根本没有哪怕是很轻微的精神损伤的迹象。