He might feel better after purging all that pent up rage and sadness. I know several people that have to have a yearly breakdown where they let out everything they had been keeping bottled up inside. Sometimes with the spectrum you can be feeling things and not even know it until later when they come screaming out...It could also be the medication is a factor? Maybe he will be more expressive, not in that extreme...idk, just some thoughts. Hoping the medicine will work for him and he will be able to deal with all the issues surrounding him better.