Brain imaging provides ever more sensitive measures of structure and function relevant to human psychology and has revealed correlates for virtually every psychiatric disorder. Yet it plays no accepted role in psychiatric diagnosis beyond ruling out medical factors such as tumors or traumatic brain injuries. Why is brain imaging not used in the diagnosis of primary psychiatric disorders, such as depression, bipolar disease, schizophrenia, and attention-deficit hyperactivity disorder (ADHD)? This article addresses this question. It reviews the state of the art (...) in psychiatric imaging, including diagnostic and other applications, and explains the nonutility of diagnostic imaging in terms of aspects of both the current state of imaging and the current nature of psychiatric nosology. The likely future path by which imaging-based diagnoses will be incorporated into psychiatry is also discussed. By reviewing one well-known attempt to use SPECT scanning in psychiatric diagnosis, the article examines a real-world practice that illustrates several related points: the appeal of the idea of image-assisted diagnosis for physicians, patients and families, despite a lack of proven effectiveness, and the mismatch between the categories and dimensions of current nosology and those suggested by imaging. (shrink)

This Editorial introduces the thematic series on 'Toward a New Psychiatry: Philosophical and Ethical Issues in Classification, Diagnosis and Care' http://www.biomedcentral.com/series/newpsychiatry.

The book "Philosophical Foundations of Neuroscience" is an engaging criticism of cognitive neuroscience from the perspective of a Wittgensteinian philosophy of ordinary language. The authors' main claim is that assertions like "the brain sees" and "the left hemisphere thinks" are integral to cognitive neuroscience but that they are meaningless because they commit the mereological fallacy—ascribing to parts of humans, properties that make sense to predicate only of whole humans. The authors claim that this fallacy is at the heart of Cartesian (...) dualism, implying that current cognitive neuroscientists are Cartesian dualists. Against this claim, we argue that the fallacy cannot be committed within Cartesian dualism either, for this doctrine does not allow for an intelligible way of asserting that a soul is part of a human being. Also, the authors' Aristotelian essentialistic outlook is at odds with their Wittgensteinian stance, and we were unconvinced by their case against explanatory reductionism. Finally, although their Wittgensteinian stance is congenial with radical behaviorism, their separation between philosophy and science seems less so because it is based on a view of philosophy as a priori. The authors' emphasis on the a priori, however, does not necessarily commit them to rationalism if it is restricted to conceptual or analytical truths. (shrink)

A common theme in the contemporary medical model of psychiatry is that pathophysiological processes are centrally involved in the explanation, evaluation, and treatment of mental illnesses. Implied in this perspective is that clinical descriptors of these pathophysiological processes are sufficient to distinguish underlying etiologies. Psychiatric classification requires differentiation between what counts as normality (i.e.- order), and what counts as abnormality (i.e.- disorder). The distinction(s) between normality and pathology entail assumptions that are often deeply presupposed, manifesting themselves in statements about what (...) mental disorders are. (shrink)

A pluralistic view of psychiatric classification is defended, according to which psychiatric categories take a variety of structural forms. An ordered taxonomy of these forms—non-kinds, practical kinds, fuzzy kinds, discrete kinds, and natural kinds—is presented and exemplified. It is argued that psychiatric categories cannot all be understood as pragmatically grounded, and at least some reflect naturally occurring discontinuities without thereby representing natural kinds. Even if essentialist accounts of mental disorders are generally mistaken, they are not implied whenever a psychiatric category (...) that is not pragmatically grounded is posited. (shrink)