Hi. If you've heard me rant about these, which I've been doing a bit, I'm sorry. My goal here is to present two controversial hypotheses briefly and have, hopefully, a constructive discussion.
- Turhan Canli's (editor of Oxford Handbook of Molecular Psychology), hypothesis that depression is an infectious disease. (https://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780199753888.001.0001/oxfordhb-9780199753888-e-28)
(Brief context: I imagine one a bit like tuberculosis, which due to its latency period most doctors didn't think was infectious but genetic and ubiquitous before Koch managed to culture its cause. Perhaps incidentally, the first antidepressant was originally an anti-tuberculosis drug.)
- Paul Ewald's hypothesis that chronic, hard to culture/diagnose infections underlie many leading chronic conditions in the US and play a substantial role in aging.
(Brief context: E.g. C. pneumoniae for coronary heart disease -- arterial plaques being biofilms like those created by bacteria on teeth, to improve resilience against the body and antibiotics; the article Do Microbes Trigger Alzheimer's? in The Scientist featuring J Miklossy of Cambridge Expert Reviews in Molecular Medicine; intracellular bacteria as a potential contributor to aging, killed by autophagy in accordance with Anti-agingfirewall blog's model, and consistent with certain substances that have antimicrobial properties like polyphenols or sodium nitrite apparently increasing lifespan. Leaves and corpses decompose in nature due to microorganisms so this is a natural hypothesis to explore. There may be other important factors though. Formaldehyde for example doesn't generally increase lifespan, it's a straight carcinogen. Considerations of dose, dietary context, microecology, immunomodulators, and metabolites seem relevant.) (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715324/) (https://www.health.harvard.edu/newsletter_article/Inflammation_A_unifying_theory_of_disease) (http://microbeminded.com/2017/11/11/interview-with-evolutionary-biologist-paul-ewald-infection-and-chronic-disease/)
(Discussion) These hypotheses are pointed at things that contribute to hundreds of billions or trillions in healthcare costs annually and countless years of human misery and lost productivity. (http://www.nationalhealthcouncil.org/newsroom/about-chronic-conditions)
General paresis and syphilis illustrate that it's theoretically possible for microbes to do such things; Coprococcous and Dialister that they could do so unnoticed. As such, I think these hypotheses and infectious disease research in the West merit more serious attention than a crude post like this from someone like me can give.
If these hypotheses were reasonably likely to be true, I would think expanding existing technologies like Charles Chiu's metagenomics research would be super worthwhile as EA investments. (https://www.nbcnews.com/health/health-news/boys-mysterious-infection-cured-after-dna-sequencing-n122871). Improved infectious disease diagnostics seems like a very good idea for biosecurity considerations as well. (https://medicalxpress.com/news/2018-10-cdc-mysterious-disease-paralyzing-children.html) (https://www.mercerislandbooks.com/book/9780385334969)
Some examples of infectious etiologies for seemingly psychiatric conditions that seem to be well-documented include the article How the Hookworm Gave The South a Bad Name, or hepatitis C inducing depression, or malaria, or a recent example: cytomegalovirus antibodies and bipolar. (https://www.quora.com/share/A-bipolar-disorder-patient-becoming-asymptomatic-after-adjunctive-anti-filiarasis-treatment-a-case-report-1). Hippocampal lesions found in epilepsy and schizophrenia seem almost suggestive of it (via Brainstorm, O'Sullivan, Ch. Adrienne).
From a current literature/technology standpoint it seems to me that potentially microbes could be a very common, neglected, and tractable cause of mental and chronic illness, analogous to the percent of cancers we now know are caused by viruses trend in the Microbeminded article.
Thanks very much for spending your time to read these thoughts and all your dedication and hard work. A great community we have.
***Ideally, I'd rework this post a lot to be suitable for sharing more broadly but I don't have a PC or the resources at this moment. I've expanded a little on these hypotheses on Facebook and Quora and could copy paste bits from those at some point. This is the first public place I've articulated these thoughts, I hope, coherently like this.