[geon]

I think ADHD is linked to caffeine insensitivity. I experimented with caffeine at uni, but never noticed any effect. I would drink a 33 cl coke, containing some 30 mg caffeine.

Some 10 years ago I tried caffeine tablets in the mornings. They might have been 100 mg. I would take a tablet 30 min before work. That time, it would take the edge off my morning sleepiness which I’ve suffered from my whole life. But instead I would crash completely at 3-4 in the afternoon, so it didn’t feel worth doing.

[herbst]

Did you try l-theanin? That is contained in green tea and arguably one of the reasons you don't get caffeine rushes and withdrawals from excessive tea use.

I use it mostly against anxiety I can get from high caffeine intake.

On the other hand dextroamphetamine works just long enough for an average work day and has much fewer crash symptoms than other common amphetamines. I wouldn't recommend abusing it for work tho, that's a downward spiral IMO.

[hilbert42]

Insensitivity to caffeine is pretty common. As I said in my post, I'm insensitive to it but then I've regularly consumed large quantities of it almost every day since I was a kid (I've always drunk very strong tea and coffee without milk or sugar), so I'd expect to be desensitized.

Perhaps there is an ADHD connection but that desensitization also occurs to those who don't have it. Caffeine is just like any other psychotropic drug, it doesn't take long to develop a tolerance.

BTW, 30mg caffeine is hardly enough to get one off the starting block, a strong cup of coffee can have three to five times that amount.