"ABA is considered an evidence-based best practice treatment by the US Surgeon General and by the American Psychological Association.
“Evidence based” means that ABA has passed scientific tests of its usefulness, quality, and effectiveness. ABA therapy includes many different techniques. All of these techniques focus on antecedents (what happens before a behavior occurs) and on consequences (what happens after the behavior)"
"More than 20 studies have established that intensive and long-term therapy using ABA principles improves outcomes for many but not all children with autism. “Intensive” and “long term” refer to programs that provide 25 to 40 hours a week of therapy for 1 to 3 years. These studies show gains in intellectual functioning, language development, daily living skills and social functioning. Studies with adults using ABA principles, though fewer in number, show similar benefits."
This information is quoted from the resource provided below: