Schizophrenia: The new etiological synthesis

> We suggest that one reason why the prevalence of psychosis among people with hunter-gatherer and traditional lifestyles is so much lower than in people with contemporary western lifestyles is due to chronic stress and low-grade systemic inflammation caused by western lifestyle.

Why is chronic stress important? It brings impaired immune response and chronic inflammation. This lets a number of parasites through the door, one of which is _Toxoplasma gondii_, the mind-control parasite that causes mice to not fear cats.

> In light of the parasite x genotype x stress model, a probable explanation for why living in cities increases the risk of schizophrenia is increased chronic stress caused by urban living (see Lederbogen et al., 2011). City living is associated with increased amygdala activity and affects the perigenual anterior cingulate cortex, a key region for regulation of amygdala activity, negative affect, and stress (Lederbogen et al., 2011). Functional magnetic resonance imaging research has shown that city living and urban upbringing are associated with altered neural processing of acute social stress (Lederbogen et al., 2011). There is also substantial evidence indicating that visiting green spaces and being exposed to natural environments reduce psychological stress (Ewert and Chang, 2018).

> Living in cities can increase contact with Toxoplasma gondii through domestic cats because cats have a more limited choice of defecation sites in urban areas (Torrey and Yolken, 2014). Likewise, it is possible that the high prevalence of schizophrenia among people with contemporary western lifestyles compared to hunter-gatherers might be caused by the higher prevalence of domestic cats and diseases associated with them. It is also possible that contemporary western lifestyles and living in cities negatively influence gut health and gut microbiota (Fig. 1). Further evidence for this hypothesis comes from findings showing that people with hunter-gatherer lifestyles have more diverse microbiota than people with contemporary western lifestyles (Sanchez-Quinto et al., 2020, Segata, 2015, Singh et al., 2019, Yatsunenko et al., 2012).

When I first learned how HIV (and retroviruses) worked, it was the same level of amazement. Like "it splices its own genes into your cells' DNA, and when your cells reproduce, they additionally make copies of the HIV virus" is just something that I would have never thought was real.

I think folks like myself, who became an "amateur epidemiologist" during covid (out of necessity, because of the information vacuum) were shocked to learn all these amazing things we weren't ever told. As an aside, the same is true for everyone who is now an "amateur diplomat" post-invasion and read about realism etc. and well-understood and reasonable explanations for "why the U.S. is always at war" that make it seem so logical. Crazy to think there are so many other fields keeping amazing secrets like this.

Nature is fucking terrifying. Every time I see some zoo program on the telly where "oh we're rehabilitating these endangered rabbits and then we'll release 'em back into the wild where they'll be free and happy". Not sure that's how the rabbits feel about it.

If I were a rabbit in one of these programs I'd feign a limp, hide in the corner, anything I could to avoid being cat or wolf fodder, or getting one of the dozens of tortuous diseases and parasites that infect rabbits in the wild.

>He added: 'He suffered several injuries and trauma to the head and the pelvic area. 'We have high hopes that will recover and that will be fine.'

How is this guy the victim here? What about the lions?

[Edit: retracted dumb speculation]

In popular culture: https://achristmasstory.fandom.com/wiki/The_Bumpus_Hounds

It's a cultural thing; I'm not arguing there's some kind of "dog toxoplasmosis". Wikipedia says the evidence for (feline) toxoplasmosis causing crazy cat ladies is not definitive, either. https://en.m.wikipedia.org/wiki/Toxoplasmosis#Society_and_cu...