The depakote is supposed to work similarly to how it works when prescribed for epileptic seizures. In a seizure, the brain is firing irradically causing the body to contort and spasm. In bipolar disorder, the mind is flip-flopping pole to pole in a similar fashion. So in large doses, depakote has been found to ease this constant mood swing and irratic behavior. If he was stable with the depakote and these changes occured shortly after he stopped taking it, I would say your suspitions are correct.

The other July, I ran out of my depakote and was off medication for 12 days straight. The mania and mood swings that followed were out of control. I would recommend some kind of action before this spirals out of control to the point he will need to be hospitalized.

Best wishes and good luck