[LeonM]

The one thing that is often a dead giveaway is how many stimulants seem to have the opposite effect on people with ADHD.

I have ADHD, amfetamines help me relax, caffeine causes me to fall a sleep, some anti-allergy medication can cause me to stay awake for 2 days straight.

I read that in some countries doctors can prescribe mild sleeping pills for babies to help them stay calm during long flights. They always advice to test it before going on the flight, because some babies can actually become hyperactive from that medication. If that happens, there's a good chance the baby has ADHD.

[rwyinuse]

I think it still varies a lot between individuals. Caffeine often makes me more anxious, the effect on mental energy levels seems kind of random (either short burst of energy or just more tired mentally). Yet when I tried methylphenidate it made my mind calmer, clearly reduced anxiety and helped focus while increasing energy. At the same time it gave me pretty bad insomnia, stomach issues etc.

The best I can describe it is that I felt calmer in my mind, but overstimulated in my physical nervous system.

[dizze]

I think it depends on what sort of ADHD it is and what stimulant. I feel somewhat more alert after a coffee, but cocaine does nothing. Amphetamines calm the noise from my mind, but make it more difficult to sleep if they're long-release ones.

[imzadi]

This has been the most difficult part for me. I see people in reddit subs talk about how stimulants changed their lives. They are suddenly alert and productive and happy with the world. I get medication envy. I take adderal and fall asleep. Other stimulants I either get no effect or I get anxiety and zero benefits. It's very frustrating.

[throwaway173738]

It’s diphenhydramine, or Sudafed. Also sometimes sold as Unisom but to be distinguished from the Unisom that is Doxylamine. My 18-mo old had the paradoxical reaction.

[teach]

You mention three different medications here:

- diphenhydramine aka Benedryl is an antihistamine with a common side effect of sleepiness

- doxylamine aka Unisom is also an antihistamine but these days people only really use it as a sleep aid or for nausea

- psuedoephedrine aka Sudafed is a decongestant. Not sold over-the-counter because it can be used to make meth. It's a stimulant and appetite supressant

Finally, there's "Sudafed PE" aka phenylephrine, which is also sold as a decongestant but it (literally) doesn't work