In this commentary on Anneli Jefferson’s book “Are Mental Disorders Brain Disorders?,” I offer an overview of her central thesis, and then propose my own modified account of when we are justified in calling mental disorders as “brain disorders.” In doing so, I draw on recent work in neuroscience that understands the relationship between brain and behavior in complex, dynamic, and computational terms. In particular, I disagree with Jefferson’s criterion of sufficiency, that a particular brain process should always realize a (...) psychological dysfunction. I propose that a psychiatric disorder can be said to be a brain disorder if there are empirically identifiable systematic brain differences associated with it and if these associations are contextualized within a scientifically robust theoretical understanding of the relationship between brain and behavior. I conclude by preliminary reflections on whether the issue of “mental disorder” versus “brain disorder” comes down to “the language of psychology” versus “the language of neuroscience,” and the degree to which the former can be expressed in the latter. (shrink)