I'm not sure if it is related to the
Humalog. The child may be having these mood swings due to his
insulin level increasing and decreasing during the day. When his mood swing begins I would check his blood sugar. If it is low he can have an increased heart rate and tremors. I actually have low blood sugar and when it gets low I become very agitated and get in a really bad mood. After I eat my mood stabilizes and i'm calm and in a better mood. most likely his body is reacting to the amount of sugar he has in him. His blood sugar flucuating could definatly be why he has mood swings. I would start checking his sugar more often. Make a chart, take it when he starts with his mood, then try in between and when his mood stabalizes. This might help you to figure out a pattern to control it. I would also talk to your doctor about this. Hope this info helps you