I'll try to reply quickly, as I think we at least mostly understand each other, and it's time to sleep where I am.

> That's simply not true that all (or even most of) our genes have been selected for "for tens/hundreds of thousands of years". Most diseases that occur after reaching reproductive age are not strongly selected for (this also holds true for animals). On top of that human social structures also help to weaken/circumvent evolutionary pressure.

All the conditions we're talking about can very often express before reproduction happens; anxiety, depression, ADHD, bipolar, personality disorders, even schizophrenia (though that's later than most but still by the early 20s). And it's always been common for men to reproduce well into advanced age.

I gather you're arguing that mental "illness" hasn't actually been positively selected for by evolution, but in fact is just caused by crappy DNA that entered the gene pool by mistake and has stayed on for the ride.

It's a coherent claim, but doesn't really pass Occam's Razor.

For all the conditions I listed above, we can see how, in certain circumstances, they can be beneficial either to the individual or the group, so we don't need to conjure up an assumption that their emergence and persistence were undesirable accidents.

> I'm lactose intolerant

I'd be happy to research and debate this further at a later time if it turns out the topic materially hinges on this

> I also don't see a big distinction between "curing" it "creating better conditions". Isn't curing it a way to create better conditions?

It's a case of treating the symptoms vs the cause that pertain's to one's own life (their life experience and/or their environment).

Take the ADHD example. Current common treatment is to prescribe amphetamines. Future treatments according to this article might be to "switch off" the gene that causes ADHD-type behaviour. My "better conditions" approach is to look at the kid's overall personality and environment, investigate whether there's any trauma or distress underlying the behaviour (which is tragically often overlooked in the current treatment model), then once you've ensured the kid is in a safe and nurturing environment, if they're still hyperactive or unfocused, look at their whole personality and direct them towards activities that are suited to their talents and strengths (this happens sometimes but not nearly enough).

Using drugs or genetic treatments or anything else to "switch off" the ADHD is most likely to end up being somewhere between a lamentable underutilisation of talent/ability, and an egregious act of neglect/abuse.

When we treat genes as the "cause", we overlook so much in someone's life experience and environment that is highly controllable and that can have a far greater impact than by interfering with genes or biochemical pathways.

> I'd like to see scientific evidence that bodies develop diseases to get people "to clean up their diet" or be introspective.

The very existence of physical discomfort/pain or emotional distress is a demonstration of the biological signals we've developed to motivate changes to our conditions or behaviour.

We all know that eating too much of the wrong kind of food or drinking too much alcohol leads to physical and emotional pain/discomfort/distress that tells us to change.

Same goes for dysfunctional behaviour that leads to a relationship breakup or social rejection, leading to a period of introspection.

Sometimes the link between pain/illness and behaviour/environment is not so clear-cut, so we need to see a practitioner or do some research of our own.

But there's nothing in the least bit fringe or controversial about this concept.

> People are lazy and changing habits is hard

> we know that improving levels of exercise and adjusting your diet

I keep hearing this from experts on medicine and physiology. Some of them still dispute the "sugar is more harmful than fat" evidence (which I know is a separate issue that I don't want to start debating here/now).

I'm more optimistic about human potential.

People respond to incentives, and people will happily follow practices that clearly deliver benefits.

I know this from personal experience. I drank heavily, ate terribly, smoked and didn't stick to exercise. I tried doing everything mainstream health advocates recommended, but didn't get sustained results so I lost motivation and went back to bad old ways.

Then I found approaches that worked, and I've happily done them every day for over 8 years, because I've found that when I do, my life just keeps getting better.