PDF or something else

My son was diagnosed five months ago with Pdd nos.  He has been going to ABA and speech therapy since the time he was diagnosed.  He is a little over three now and has made tremendous improvement in his speech abilities.  The other behaviors such as spinning and lining everything up are diminishing a great deal.  I have noticed as his ability to talk improves he seems so much happier and content.  My question is since he has made such a dramatic improvement is it possible that he just has a developmental delay?  Even others are questioning the diagnosis.  He is motivated to relate to others but still gets stumped when there is reciprocal communication.  He is loving and has good social and play skills.  It seems the expressive speech is his main challenge.  He also has a very difficult time going and coming back from visitation with his dad and there is not a lot of information sharing unfortunately to ease the transitions.  I also am wondering if completely different environments and parents that aren't successful in working together could cause a developmental delay of this sort in him.  I am thankful for his improvements but confused on the cause.

[specialmom]

Hi, yes, I think he could have a developmental delay such as sensory integration/ processing disorder.  Motor planning could cause problems in reciprocal and expressive speech.  How does he do with picking up new tasks?  (using scissors, riding trike, etc.)

As to your second question,  no parents can not cause a developmental delay.  A delay happens either in utero, at birth or trauma.  Bad behavior can come from a transition between split parents----  as the child is coping with the issues.  But a delay is within the brain chemistry.  

Good luck.