On the ontological assumptions of the medical model of psychiatry: philosophical considerations and pragmatic tasks

In this paper, we explicate that realism, naturalism, reductionism, and essentialism are core ontological assumptions of the medical model of psychiatry. We argue that while naturalism, realism, and reductionism can be reconciled with advances in contemporary neuroscience, essentialism - as defined to date - may be conceptually problematic, and we pose an eidetic construct of bio-psychosocial order and disorder based upon complex systems' dynamics. However we also caution against the overuse of any theory, and claim that practical distinctions are important to the establishment of clinical thresholds. We opine that as we move ahead toward both a new edition of the Diagnostic and Statistical Manual, and a proposed Decade of the Mind, the task at hand is to re-visit nosologic and ontologic assumptions pursuant to a re-formulation of diagnostic criteria and practice.Psychiatry is uniquely problematic because debates over what mental disorders are have presented substantial challenges to medical praxis and ethics. In many ways, the question of what constitutes a mental disorder is related to uncertainties about the nature of mental experience, and the underlying relationship(s) of body, brain and mind. Traditionally, medicine has been successful in establishing etiology of diseases and disorders, and developing focal therapies based upon such mechanistic conceptualizations. The acts of medicine (i.e.- diagnosis, therapeutics, and prognosis) depend upon the ability to distinguish between what is "normal" and what is pathologic, and the evolution and practice of psychiatry has attempted to adopt and utilize the medical model in this regard.Yet, as neuroscience probes ever deeper into the workings of the brain, it becomes evident that the "mind" remains somewhat enigmatic, and thus, any attempt to link mental events to biology must confront what Chalmers has referred to as the "hard problem" of consciousness [1]. But given the continued ambiguity of the brain-mind relation