diabetes and mood swings

My friend becomes explosively violent when his sugars are high or to low. He says he also suffers from depression but I'm pretty sure he may be bi-polar. He drinks 2-3 beers every night which he knows is not good for him but still he does. He was diagnosed with diabetes when he was 9 and he's now 39. So here is my question: Could he be bi-polar or could he be violent from a combination of insulin, lotensin and paxil?

[Mandi R]

High and low blood sugar levels can cause the diabetic to be violent specially if they are having a hypo/hyperglycaemic attack. I get extremely violent & nasty even though I have no memory of it at all the next morning. A high or low level that occurs frequently can also be a cause of depression but if he can get his blood sugar levels to the right level & keep them level he will find the depression will ease if not disappear.
Of course, there may be another reason for his actions so bi-polar and actual depression may apply in this case.