That's just how stimulants are said to work for people with ADHD. They don't have enough dopamine for proper functioning, so when they do get a boost of dopamin

That's just how stimulants are said to work for people with ADHD. They don't have enough dopamine for proper functioning, so when they do get a boost of dopamine they are able to function more normally. Wired (hyperactive) -> tired. I'm not aware of antihistamines making people with ADHD wired, but I do know someone that used to get energetic when they took a benadryl.