https://www.medicalnewstoday.com/articles/325499.php
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2626918/#!po=0.261780
https://www.healthline.com/health/adhd/adhd-dopamine#treatment
These medications increase dopamine levels in the brain by targeting dopamine transporters and increasing dopamine levels.
The above articles are NOT from websites like National Institute of Health.
However, their sources are valid.
I cannot find the source or article about "that dopamine is full on people with ADHD" but I remember well that it was mentioned here:
https://www.coursera.org/learn/managing-adhd-autism-learning-disabilities-and-concussion-in-school
and if I remember correctly they explicitly say
The the prefrontal cortex is wired differently with D1, D2 receptors.
ADHD is Complicated and I am a person who has ADHD and I'm 32 years old who takes medication and I am guilty as charged from my impulsiveness