I mean, do you think ADHD is new? Did it just not exist before 1990 or whenever it was made up? Do you think
any medical condition before then covers what ADHD is/was?
Lance Armstrong when he is biking and Lance Armstrong when he is recovering are not the same either. But Lance can take drugs to get more of the biking time and less of the recovering time. This is how SPD and ADHD work. ADHD is just a medicated false mask that a schizoid person can maintain for longer periods of time than usual, without episodes of hermitude to recharge. They're doping.
Failure to maintain the mask looks like a breakdown in attention/focus. People do long, focused work because of the expectations of others. Schizoids don't experience that, but instead basically run on obsession. They stop working when that fizzles out. On pills, though, they can work forever.
The 'scientific' people serve the people making the pills and nobody else. They rename everything every few years to sell more pills. If you want a proper take on SPD, look up Millon and his subtypes. Most of the "knowledge" of conditions in the zeitgeist comes from prescription drug commercials.