He had several evaluations throughout his childhood and ultimately was evaluated extensively at Yale University.
I've posted about this before, but the medical experts at Yale University called for drastic measures, hospital programs, special education, medication, and rigorous ongoing therapy which went largely unheeded. It was found that his mother tried to appease and accomadate his disabilities rather than treat them.
Even after he finished high school when his health was deteriorating, he was allowed to have access to numerous firearms in his home.
So yes, his condition was left untreated, but he still had numerous evaluations and had therapy in high school.
The report you are referring to and the quote in your post is the same I have referenced in another thread. The report is about 112 pages long, and it is documented that he had extensive evaluations and was treated by both psychologists and psychiatrists.
But yes, it was not for lack of seeking out several mental health facilities to seek treatment, it was that everything the experts recommended went mostly unheeded. Doctors insisted that it was crucial that he take medication to control his symptoms, but his mother stopped giving them to him after one day because she said they made him severely ill.
So it is accurate that he was treated, and also accurate that the treatment was not followed through with. Imo