Vyvanse, to put simply, causes your liver to synthesize dextroamohetamine (75% of adderalls active ingredients). Its effects on your body are similar to adderall. Levoamphetamine, 25% of adderalls active ingredients (what causes adderalls body high), supposedly has neurotoxic effects on the brain, lending some credence to that author's claim. Basically these amphetamines cause your brain to eject dopamine. This is contrasted with Ritalin/concerta/cocaine which act as dopamine reuptake inhibitors, preventing your brain from absorbing the dopamine thereby casing it to over produce in order compensate. Based on what I've read reuptake inhibitors aren't neurotoxic, and can actually guard against some of the neurotoxicity of adderall/levoamphetmine.

Just to clarify, you're saying that Vyvanse doesn't have the potentially neurotoxic effects that Adderall has? My doctor prescribed me Vyvanse and anecdotally it seems to be the preferred treatment for ADD these days.