Genetics, neuroscience and psychiatric classification

Abstract

Some psychiatrists anticipate a revolution in psychiatric nosology, on the basis of emerging data from genetics and genomics. There are, however, good empirical and conceptual reasons to resist any such revolution. Basing an understanding of psychiatric entities on one of multiple biological (not to mention sociocultural and psychological) considerations is a specious method of approaching the project of psychiatric taxonomy. A classification system that lacks sufficient consensus on the phenomenology of those classified cannot be adequately buttressed by exclusively genetic accounts. This paper advocates a more diversely informed nosology that, in turn, fosters attention to broader diagnostic considerations. We explore more plausible ways in which genetics and genomics, in conjunction with neuroscience and other biological disciplines, can help to shape diagnostic classification in psychiatry. There are, of course, differing views on the degree of prominence that genetics should take in psychiatric diagnosis and classification. We outline these accounts in illustration of this continuum. Drawing on Wimsatt's work on robustness analysis, we dismiss optimistic scenarios about the potential nosological advantages of psychiatric genetics and genomics, and offer a novel defense of realism about psychiatric entities. We also briefly sketch an integrative methodology for psychiatric research and classification.