ADHD is caused by a defective gene involving the DAT1 transporter causing it to be overactive. This causes a deficit of dopamine that predominantly impacts the right dorsolateral prefrontal cortex (there are other parts impacted too, but this one is the most apparent). The brain compromises with novelty seeking behavior to rebalance the neurochemistry as a depression response, and this outwardly manifests as distractibility.

Don’t talk of things you have no clue about. Saying ADHD is “manufactured” is downright harmful. And yes, stimulants do treat it, and do so very effectively. I encourage you to learn more about it from Dr. Russell Barkley, the leading authority on the subject. He does well to dismantle the myths and stipulations and is very knowledgeable. He even has a youtube channel where he elaborately breaks down the studies in a way the common man can understand.