> it's possible for simple normal trains of thought to latch your brain into a very undesirable state.

This seems very incorrect, or at least drastically underspecified. These trains of thought are "normal" (i.e. common and unremarkable) so why don't they "latch your brain into a very undesirable state" lots of the time?

I don't think Scott or anyone up to speed on modern neuroscience would deny the coupling of mental state and brain chemistry--in fact I think it would be more accurate to say both of them are aspects of the dynamics of the brain.

But this doesn't imply that "simple normal trains of thought" can latch our brain dynamics into bad states -- i.e. in dynamics language move us into a undesirable attractor. That would require a very problematic fragility in our normal self-regulation of brain dynamics.