Hi Raisin,
So glad I could be of some help. I'm glad that your pdoc finally realized that the antidepressant was a big part of your son's problem.
Finding the right drugs takes time since everyone's body has it's own unique chemical make-up. If your son isn't normally so violent as the day you described, than it very well could have been a chemically driven impulse. I had a day like that and I'm normally very quiet and self controlled to a fault. But, I was reacting to a med change--extremely frustrated, very anxious, super agitated and irate at the same time. It was a chemical reaction and since I never experienced anything like it before, I didn't know what to do--it took over and I took a pen knife stabbed the door frame with it several times. It released the energy, but it was foolish of me. Now I know to get on the treadmill or rebounder to burn off the negative energy.
Perhaps your son could run around a track? So many folks have said running is a great outlet for those overwhelming negative feelings. The trick is to how to tell when they are coming on and do something immediately, like running, to stave them off.
Keep me posted--you'll be in my prayers. I'll be a shoulder to cry on if you need me. I'd also like to cheer on your son's successes--and yours too

Best wishes, health and peace,
JourneyUpward