The neuroscience is fairly poor but neuroscience also is not why you would open this book.
Only other thing I would have enjoyed is a little more science behind current street meth epidemic. He spends a lot of time speculating about how P2p meth is way more toxic than the meth of yore. He rather repetitively just amasses anecdotes from social workers as his evidentiary base for how harmful current meth is. Seems like it would have been easy to have someone (toxicologist, chemist, pathologist etc.) actually test street meth for level of adulterants these days to prove that P2p meth does in fact contain more deleterious chemicals than ephedrine based meth.
Overall tho a good follow up to dreamland. Would totally recommend.