I would recommend getting a 2nd opinion. Was your grandson’s mother using meth or any other drugs while she was pregnant? Your grandson’s behavior may be related to that…..I have seen these types of behavior issues and anti-social behavior multiple times in children who are born to substance abusers. Bipolar disorder diagnosis is grossly over-used in the psychiatric community. It has become a catch all diagnosis for behavior outside the norm. You may want to read up on Oppositional Defiance Disorder. It often occurs with ADHD and is common in children who are born to drug and alcohol abusers.