Won't work. Those drugs blockade this receptor

https://en.wikipedia.org/wiki/5-HT2A_receptor

and flatline

https://en.wikipedia.org/wiki/Median_raphe_nucleus

and if you wanted to measure that you would have to stick electrodes deep into your brain, no way are you going to see what is going on there from the surface.

Stuff I was doing last month got me interested in biofeedback again, I have some talent for it, I can make those mood rings change color at will.

Most of the EEG-based biofeedback devices have three electrodes around the temple and cost about $300 and don't really work because those alpha, beta, theta and delta waves all appear in different parts of the brain and can't be read out of the same electrodes. I hear you can do better with five electrodes but the five-electrode headsets I see don't advertise a price.

I wound up getting a Polar H10 heart rate monitor which can be used with HRV software

https://en.wikipedia.org/wiki/Heart_rate_variability

but the "biofeedback" apps I have seen so far seem to be breathing exercises that you could do without any hardware. I have electronics for EMG (muscles) and GSR (skin resistance) to hook up to an Ardunio and will probably try making a setup. I'm still looking for a soup-to-nuts answer for EEG biofeedback.

tFUS is a really interesting new stimulation technique for deep brain. Still emerging tech though so who knows where it will go