I am sorry to hear that your DS suffered a trauma at such a young age. My own DS had a traumatic experience at the age of 7 for which we pursued therapy right away. Part of that therapy included EMDR, though it took a slightly different form than the EMDR I received as an adult. I would say that there was some degree of success. I know others whose similar aged children have also used EMDR with success, although those children are not neccessarily in the same population you might find here.