The thesis that mental states extend beyond the skull, otherwise known as the extended mind thesis, has attracted considerable philosophical attention and support. It has also been accused of lacking practical import. At the same time, the field of psychiatry has remained largely unacquainted with ExM, tending to rely instead upon what ExM proponents would consider to be outdated models of the mind. ExM and psychiatry, therefore, have much to offer one another, but the connection between the two has remained (...) largely unexplored. Here, I consider what implications ExM may have for psychiatry and, in so doing, reveal how psychiatry may lend practical import to ExM. First, I detail the possibility of the extension of one mental state relevant to psychiatry. I augment this example by surveying other possibilities for extension in the context of psychiatric diagnoses. I then consider ways in which such extensions might alter psychiatric diagnosis and treatment. Overall, I argue that recognition of the truth of ExM could alter the diagnostic status of certain individuals by correcting both false positives and false negatives, re-conceptualize certain aspects of treatment, help us re-envision psychiatric research, and potentially increase empathy towards those individuals considered to be mentally disordered or mentally different. (shrink)