Hello. Restricted and repetitive behaviors like hand flapping could point towards possible Autism spectrum disorder and not explained by ADHD. And of course, few Autism cases are associated with ADHD too. Other core features of Autism are deficits in social communication, restricted interests, hypersensitivity to sensory stimuli and sometimes also associated with delay in speech development.
Next Steps
He might need detailed evaluation to rule out all possible co-morbidities. He might benefit from Behavioral therapy and ADHD if moderate to severe, requires medications like Methylphenidate, Atomoxetine or Clonidine. Please consult online for detailed evaluation.
Health Tips
Kindly refer to books published by COMDEALL trust for training in children with autism.