"Should my son leave his twin and return to first grade as his symptoms of ADHD worsen?"
ADDitude's Education Expert
I certainly would not recommend retaining your son. I would highly recommend a in-depth testing of his ability — both cognitive and academic. You need to know the nature of his needs and if indeed he is attention deficit.
Retention won't help ADHD — only strategies and techniques will. Move forward now and have a complete psychoeducational battery done by a reputable child psychologist in your area.