There’s a very good chance that low levels of dopamine cause ADHD. I say ‘very good chance’ because it’s the current theory. And until someone comes up with a better one, that’s what we’re stuck with.
I’m generally happy with the theory because the drugs back it up.
The drug amphetamine (also known as speed, bennies, hearts, dexies) increases dopamine levels, causing a boost of hyper alertness in the average person. But give amphetamine to someone with ADHD and it calms them.
It’s called the ‘stimulant paradox’.
The belief is that amphetamine brings the dopamine levels up to ‘normal’ within the ADHD sufferer.
So people like me take a dose of amphetamine-based drugs every morning. And we are calmer and more clear-headed because of it.
Read more about the stimulant paradox (links to AllPsych website).