Usually these articles push the most pertinent information to the end so that you'll miss it.
From your article:
Of course, it’s not all cut-and-dried: The sources of racial disparities in treatment, for instance, do not lie exclusively within these larger systems. Black families have been shown to be “skeptical of medical and mental-health research, particularly contested and controversial issues like ADHD,” and are therefore less likely to seek out treatment, while predominantly Latino schools see less medicalized andcriminalized discipline, all things being equal. “Some of the research,” Ramey says, “suggests that Hispanics and Hispanic families in Hispanic schools — in particular first-generation immigrants — tend to avoid social control institutions altogether, be it the criminal justice system, the mental-health system, or the medical system,” often due to language barriers, immigration status, and other concerns.
So your article admits that black and Hispanic families don't take advantage of the medical alternatives as much as white families.....so it's the parents that seem to want to avoid drugging their kids instead of throwing them in jail.