Most abusers of methamphetamine are not taking it orally (slow route of administration) and are generally using much higher relative dosing than ADHD patients are using amphetamines. Potential for addiction and other physical harms are greatly affected by both of those things, so the comparison has some truth, but is obviously sensationalized.

If one could 'add meth'(??) to chemicals to make them more potent, without changing the chemical, it would be the difference between (for example) citric acid and really strong citric acid, or codeine 2.5mg and codeine 5mg.

You'll note that neither of these involves changing the name of the chemical, because that is not how chemical names work.

As someone else has pointed out, the difference between 'hydrogen monoxide' and 'dihydrogen monoxide' isn't 'it's like hydrogen monoxide with added di', because that is ridiculous.

Please stop saying anything beginning with 'meth' is just meth with added bits.

It's a really odd misinterpretation of the terrible dangers of: methane, Methodists, methanol, Methaemoglobin, methicillin, etc.