She stood by him as he spiralled into drug addiction.

她支持他当药物成瘾无法自拔时。

This part of the brain plays a crucial role in drug addiction.

这部分大脑起着关键作用的药物成瘾。

MCH is implicated in depression and drug addiction as well.

在抑郁症和药物成瘾中也涉及MCH。