Dynacin and seizure

My son started taking Minocycline HCL 100MG in January and when we went on vacation the end of March, he was acting strange - imagining things, paranoid, etc. He is also on Depakote ER 500MG (1/day) - which we have been trying to get off - since he hasn't had a seizure since 2001. In April, he had a normal EEG, so he went off the Depakote and within a few days he couldn't write, concentrate or anything. I suspected the Depakote (even though this was an extremely low dosage - for 200lb. person), so we went for another visit and they did another EEG that was normal. We put him back on the low dosage - and he improved within a few days....but he still didn't seem back to normal. So I took him off of the Minocycline and I haven't noticed any of the weird behavior anymore. Has anyone else had this issue? We are going to try to go off of Depakote in July after another EEG... would like to know what caused that other weird behavior.