DTT was developed by Dr. O. Ivar Lovaas as a key part of the Lovaas Method in the early 1970s in the USA. Dr. O. Ivar Lovaas worked with non-verbal, institutionalised children on the autism spectrum in the late 1960s and early 1970s in the USA. He concentrated on improving verbal skills using applied behavioural analysis.
Unfortunately most of the children lost their verbal skills when the programme ceased and they returned to institutional life. However those who moved back with their parents did much better.
Lovaas went on to work with younger children, aged 2 to 4, in their home setting to see if the skills learned by the children were maintained. He developed Early Intensive Behavioural Intervention (The Lovaas Method) from this work.