How would we separate various mental differences into "disorder" vs "diversity"?
a) Your condition prevents you from being a functioning adult in society. You have to be in someone's care in order to function at a basic level.
b) You're a functioning adult in society but you (or others, or both) perceive your condition as a handicap that hurts areas of your life and needs to be fixed.
c) Your condition is a mixed bag and you perceive it as beneficial in many ways.
I'd say (a) is definite "disorder" territory, (c) is leaning into "diversity", and (b) is a gray area. It could be "diversity" if you choose to embrace it and live with it, or a "disorder" if you're set on keeping it at bay.
A huge difference between autism and the other listed things is that autism is not (and never will be) legitimately treatable, while depression, anxiety, and ADHD are treatable and have been for a long time. Amphetamine targets dopamine dysregulation and it's highly effective at improving quality of life.
Autism has no equivalent. No drug has ever shown efficacy in improving the quality of life of autistic people, nor has any therapy. They've all been damaging, and the mainstream autism junk-science treatment today is ineffective according to meta-analyses[1], is based on gay conversion therapy, has been shown to cause PTSD[2].
Treating autism stops making sense (and thinking of it as important to identity starts making sense) when you realize that having an autistic brain means using a different but equally-effective social model[3], mode of thinking, and algorithms for processing information, that in many cases has tangible advantages.
[1] https://therapistndc.org/aba-is-not-effective-so-says-the-la...
[2] https://www.emerald.com/insight/content/doi/10.1108/AIA-08-2...
[3] https://www.frontiersin.org/articles/10.3389/fpsyg.2020.5861...
* Antidepressants are barely better than placebo.
* Benzos are a short-term bandaid, best reserved for panic attacks.
* Antipsychotics have truly horrifying permanent side effects.
Amphetamines are a borderline miracle. Again, comparatively. Nothing else available today comes close in effectiveness at treating any psychiatric disorder. They definitely have their shortcomings, but for people with ADHD they're such a huge boost to quality of life and lead to better overall life outcomes.
There's a chance pharmacological depression treatment will catch up to where ADHD is at if/when ketamine become commonly available. Same with PTSD and MDMA. The future of anxiety treatment looks a bit more bleak... but there's experimental stuff out there with HDAC inhibitors and I think some other stuff causing fear extinction.
As far as I know, LSD and psilocybin both have a roughly two week tolerance curve.
On average, the acceptable "separated from placebo" margin doesn't have to be that high, but the range of effect is absolutely enormous, even within close relatives.
Antidepressants that did nothing positive or negative for me or some family members were either extremely helpful or extremely harmful to other family members of mine. (Almost never vice-versa; my biochemistry appears to be quite stubborn about responding to a great many classes of treatment, well _or_ poorly, but at least one medication just made me feel completely numb while being extremely helpful to another relative.)
It can also be a weird multidimensional variable in ways many people don't expect - one medication I'm currently taking for depression is 4 pills twice a day (very short half-life), because I was gradually tapering it up. We tried switching to the same manufacturer's single pill that was 4x the dose, twice a day, and immediately I started feeling extremely nauseous whenever in a moving vehicle, which has never happened before. Switch back, problem goes away.
(I know the above sort of outcome is not exclusive to mental health medications, but in my personal experience, I've never had any other medication type vary in outcome based on whether they gave me one or multiple pills adding to the same dosage.)