Meth is good medicine?
Under the heading life's little mysteries, it turns out that while meth can cause a stroke if you take it to excess while you're healthy, meth can save your life after a stroke. It protects against further damage if administered in low doses after a stroke has occurred and in fact test animals dosed up to 16 hours after a stroke, showed that their neurons were as intact as those in animals that hadn't had strokes. Ironically, scientists discovered this accidently while trying to prove meth use causes lung damage.
It just goes to show that no currently illegal drug is entirely bad and it's a good reminder that drug use is not the same as drug abuse.