Pop science with no link to actual study? I'm not convinced that confounding variables have been stripped. ADHD and autism are probably also positively associated with the population density of medical professionals in the area.
There is a link to article in Elsevier's Environment International journal. Looking at its ranking it is not some totally crap journal (which does not prove that this particular article is correct, though).
ADHD is generally just when your executive functioning doesn't develop as well as the rest of your brain, and so things are asymmetrical. You have less control over your actions because executive functioning is impaired. This gets commonly confused with highly intelligent people who cant/refuse to focus on the boring and mundane. So we get this mythos, but really, the highly creative intelligent get mixed up with cognitively impaired.
There are other types of people who for whatever reason have imbalance in the regions of their brain and end up with unique functioning. This is where "edge" comes from. Deformities that lead to small verticals of super human capability, which comes at the expense of being able to live a normal life.
Conscientiousness—the ability to make and follow a plan—is also a major dimension of personality psychology. Some people are just way less planned and focused by nature.
Edit: link to article https://www.sciencedirect.com/science/article/pii/S016041202...