Son 6 years old extreme mood swings

I have a 6 year old son who has severe mood swings. He has been sent to the office for fits he is throwing in class. It seems the smallest thing will set him off. If he thinks his pencil isnt sharp enough or he is not getting his way with his friends, he will flip his desk, throw things, yell, take off out of the classroom. Within minutes he seems to be ok again. Im worried that he is at risk of being kicked out of school. We have tried every type of discipline from spanking, time outs reward systems, taking toys away, grounding everything we can think of. I recently took him to see a mental health nurse who within 5 minutes told me she believed that he was add or adhd. I strongly disagreed seeing as he can sit still and can maintain focus. His teacher also does not believe that he is add. Im at a loss and feel like pulling my hair out almost everyday when i pick him up from school and have to hear about his tantrums and trips to the principals office. I am wondering if anyone on this site has a child this age with bipolar as all the research i have done points in that direction. I am not sure how i would go about even having him diagnosed with such if that is the issue because this mental health nurse is insistent on add. Any insight would be helpful.

Talk with the school counselor, they have plenty of resources and information that may be helpful to you. I would also see your pediatrician and look into getting your son to a child psychologist.

Keep us updated. I wish you and your son well.