His slipping into his own self is keeping him away from learning new things hence he is not speaking and doing things. You have to train his mind to be out of the Inward State .
Autistic Kids -A big No To Regular School I was treating a child who was three and a half with moderate level of Autism and no speech .Taking the child to your Family doctor or a pediatrician can at times delay the diagnosis as some of them might be not clinically trained to identify Autism Spectrum Disorder ( I could be wrong here , as the clinical training differs from country to country and also the experience and the awareness has a strong bearing on the knowledge of the Pediatrician.).A Neuro developmental specialist is the right person for diagnosis.I have seen that children recover from autism more when their parents are actively involved in giving therapy to the child at home .Autism therapies are no rocket science ; one can easily learn them .Once the diagnosis is done, it is very essential to come to terms with the diagnosis as fast as possible.I have seen that most of the parents struggle with the diagnosis for months or years together, which is extremely harmful for the child.My Clinic deals with nearly 3-5 new cases of autism every day and a follow-up of at least dozen Autism cases every day.Autism Intervention -Earlier the Better Start early.When a child with autism slips into his self , his passive learning is not taking place hence he is not learning. Keep him engaged in a loop with you and the regular world around him Parents are the best Therapist for Autistic kids There is no harm in engaging a therapist or taking your child to the Autism therapy centre as long as you are spending a lot of time with the child.Taking the child to the best therapist or the best therapy centre makes the parents believe that they are doing their bit and the child will automatically or over a period of time recover from autism because of the therapy he is receiving; where as what is actually happening is that the all the good work that therapist is doing , is getting anti doted by the hours of isolated state that the child slips into when he is back home. I have always suggested parents to take more pro-active role in the execution of therapies.