Ok but how do you know your anecdote is merely coincidental? How do you know there is a strong causation without data?
Yes, you need more rigorous documentation to get it into the medical literature and prescribed by doctors and yadda. But experimenting on yourself? It's totally possible to draw a firm and reasonable conclusion that "X diet is helpful for managing my symptoms and making my life more functional."
* Observed data, not necessarily documented.
Spent years doing trial and error with medications and food. 1 change at a time to see how things affected me.
I get crap from everyone for doing this. Family, doctors, etc.
Results is I have a long sheet of medications and exact effects and drug interdictions.
Gotten to the point where I asked my doctor about an interaction of 2 drugs I was on. He was very dismissive, claiming not possible.
Asked pharmacist, who filed both of them. After a confused moment, she said yes, rare but seperate doses by 12 hours to be safe.
But for the assertion here that "ketogenic diet helps with schizophrenia," neither a ketogenic diet nor schizophrenia are subtle things.
And that last tip of separate things by X hours? That's actually a generally useful thing that applies to a number of things.
Calcium and iron interfere with each other, which is likely why a kosher diet has edicts against consuming beef and (I think) cheese/milk products together in the same diet. I try to separate them by at least 30 minutes, especially if I am specifically trying to treat anemia or a need for calcium. (But I generally try to separate them because consuming them together amounts to wasting the nutritional resources they represent.)
Zithromax (plus related drugs, I think) and magnesium are supposed to be consumed separately. They use the same attachment sites on a cell and actively interfere with each other's absorption. So consuming them together means you don't get the magnesium you need and you are undermining the effectiveness of the drug you are on.
In the opposite direction, some things need to be consumed together for best effect. This is the principle advocated for in the book Diet for a Small Planet that promotes protein complementarity as a means for vegetarians to get enough protein.
In later writing, she says she regrets making it sound so challenging. Most historically vegetarian ethnic diets already use ingredients in the appropriate ratios, so many traditional dishes already fit the model she advocates for.
The book also has a few really excellent recipes in it, so it's worth having even if you skip the first half of the book which is a political work outlining how beef contributes to civil war and starvation globally and proving that all countries, even poor countries, can feed their people on traditional locally sourced diets. What we can't do is sell imported beef to peasants and expect them to be able to afford it as a staple and a lot of starvation is due to war (often civil war) cutting people off from food access.
It's more complicated than that and if you want a stronger argument for promoting vegetarianism as the practical choice for reducing some of the problems in this world, it's got some excellent information in it, better than a lot of the BS scare tactics and high-handed moralizing that is all too common. But you can just flip to the back of the book and look up Complementary Pie (a bean and rice quiche dish) or Mjeddra and happily go to town cooking.
The ketogenic diet has many side effects and it can be very harsh. Because of this, I found myself going on and off of it frequently in the beginning. My psychotic symptoms, just as described by that doctor, came and went in perfect correlation with whether or not I was in ketosis. I would wake up in the middle of the night multiple times, getting just one or two hours of sleep. This is a textbook aspect of psychotic disorders. Then when I was in ketosis I would get a full nights sleep like a baby. It could not have been the placebo affect. There was nothing else that correlated with the changes in my symptoms. There was no ambiguity, it was extremely obvious.
Putting all of that together, I think it’s quite convincing.