pharmafag here.  the entire "science" behind brain scans to diagnose psychological diseases is completely and utterly fabricated. the prevailing theory is that adhd is likely some form of dopamine receptor density problem. the result of this is executive dysfunction. the term "adhd" is actually not very useful, essentially, executive dysfunction, once understood describes adhd perfectly.  since there is no reliable, accurate way to measure dopamine receptor density in the brain, we have to rely on observational data and what this disease responds to. we know that amphetamines and similar drugs like methylphenidate (ritalin) increase the amount of dopamine and norepinephrine neurotransmitter in the brain.  we know these drugs provide relief for symptoms associated with adhd, this is why it's called the dopamine hypothesis. the fact of the matter is that it could be much more complex than we think. this is because we do not fully understand dopamine's role as a neurotransmitter and the downstream effects it has on things like neurological performance, vigilance and executive functioning.  so yes, something is causing executive dysfunction in an increasing percentage of people. we do not know what causes it. there's evidence that it is more inheritable in children with 30+ yo mothers who have a history or family history of adhd.  older mothers = more children and eventually adults with adhd and autism. this is likely enhanced by the environment that children grow up in. gaming and screen usage in general likely exacerbates adhd, because as the brain is developing in very young children their brain latches on to this environment as their "base setting" and becomes fundamental to how the brain interacts with the environment.  essentially, if you play games eight hours a day from five years old to twelve years old, your brain thinks those games you played are your reality and environment and has developed as such. this results in executive dysfunction.
United States