Fascinating insights into the past and future of psychiatric diagnosis:
In the US, psychiatric disorders are classified via a manual called the DSM. In early versions of the DSM, diagnoses were linked, in part, to their suspected causes. This changed in 1980 with the DSM-III, where disorders were classified purely by their symptoms, an "atheoretical" approach. The spirit was two-fold: 1) We don't actually know their causes and 2) We need to create more consistency around how patients are diagnosed. That was a lot better, but it also came with it's own host of problems.
Among them: the same symptoms show up for a lot of different disorders, and there's suspicion that the diagnostic classes aren't quite right. We're now up to the DSM-V and a recent preprint quantifies just how overlapping the symptoms are there: there are 202 diagnoses; 628 distinct symptoms, and 37% of symptoms are repeated across multiple diagnoses. In an extreme case, every symptom of every diagnosis in the Bipolar and Related Disorders chapter is repeated in other chapters:
https://psyarxiv.com/u56p2/
How can we do better? First, by agreeing to maintain the DSM while trying to find a better diagnostic scheme (that's called pluralism). Then there are two paths forward. The first is one in which we pinpoint biological and nonbiological causes and reincorporate them into the diagnostic scheme (there's a lot of work going on this realm but it's proving to be really hard, https://pubmed.ncbi.nlm.nih.gov/20595427/). The second is to reclassify everything using more quantitative approaches: https://hitop.unt.edu/sites/hitop.unt.edu/files/Kotov_et_al_2017_-_HiTOP.pdf
@NicoleCRust It's, hum, not entirely constructive, but I like this comment from Insel when DSM V came out in 2013
“As long as the research community takes the D.S.M. to be a bible, we’ll never make progress,” Dr. Insel said, adding, “People think that everything has to match D.S.M. criteria, but you know what? Biology never read that book.”
@cyrilpedia
Excellent quote. But then!
"I spent 13 years at NIMH really pushing on the neuroscience and genetics of mental disorders, and when I look back on that I realize that while I think I succeeded at getting lots of really cool papers published by cool scientists at fairly large costs---I think $20 billion---I don’t think we moved the needle in reducing suicide, reducing hospitalizations, improving recovery for the tens of millions of people who have mental illness. I hold myself accountable for that."
https://www.wired.com/2017/05/star-neuroscientist-tom-insel-leaves-google-spawned-verily-startup/
The thing that keeps me optimistic (and sane) comes from not from our scientific leaders, but from philosophy: #hasokchang
"If we hit upon some stable and effective classificatory concepts in our inquiry, we should cherish them (calling them “natural kinds” would be one clear way of doing so), but without presuming that we have thereby found some eternal essences. The old familiar metaphor of “carving nature at its joints” should be replaced by a humbler motto: “suck it and see.” Here the notion of epistemic iteration becomes important again. It is logically possible that there might be a static system that serves all our purposes. More likely, however, what we need, and what we have in most successful sciences, is a steadily evolving system."
https://doi.org/10.1093/med/9780198796022.003.0029