In her book “Are Mental Disorders Brain Disorders?” (2022), Anneli Jefferson proposes that brain processes that always realize mental dysfunctions are brain dysfunctions. This paper explores possible interpretations of two underdeveloped aspects of this thesis. First, it argues that “realization” should be interpreted as partial rather than full realization. Second, it argues that the “always” should only quantify over biologically normal situations. Taken together, these changes can account for the fact that some psychological dysfunctions are partially realized by functional mechanisms, (...) for the existence of psychological dysfunctions due to mismatches rather than brain dysfunctions, and for the fact that brain dysfunctions do not cease to be brain dysfunctions just because they can be compensated. (shrink)