ABA is behavior modification. If initiated very early (like age 2 or 2.5), it can be very effective at minimizing some of the major effects of autism. Technically, the child is still autistic (somewhere on the spectrum), but is now more able to focus and learn. When done properly and intensively, ABA has about a 60% effectiveness track record.
It wasn't until our oldest son turned 4 that he was diagnosed with high functioning autism. Soon after that we enrolled him in the SECEP Program for Autistic Children here in VA Beach. This program has made a HUGE difference in our son. At 7 yrs of age he has the language skills of a 3 yr old and is writing at the kindergarten level. It takes a LOT of work but ABA has benefited us greatly.