This is drug war propaganda. Methamphetamine is just another stimulant drug like Adderall. What makes it dangerous are these kind of articles and its illegal status. It is not dangerous when it is purchased from a pharmacy.
The article doesn't really have anything to do with pharmaceutical sourced Methamphetamine.
The author contrasts contemporary street meth, which is reportedly created in vast quantities using a variety of toxic industrial chemicals, to illicitly produced meth from 15+ years ago, which was primarily made from naturally-occurring ephedrine.
The point of the article, I believe, is to outline how synthetic production has changed the end product and the way it affects the user. It is said that psychosis observed in users of the early 2000's type of ephedrine-sourced meth was typically due to the user being awake for several days, where as modernly produced meth can induce such psychosis within hours of use. This seems to indicate higher neurotoxicity, and the author questions whether it is due increased potency or contamination of product through production.
Agreed. Most people are not aware how similar street drugs and prescription drugs can be. It is a strange dissonance because it conflicts with what people think about medical doctors / psychiatrists.