My son is mentally ill - can anyone help me?

My son suffers from panic attacks, is violent and aggressive and antisocial. We have had son counselling through his school and a shrink but they never see the him that I have at home. He is very good at putting on a front and appearing ok. Aside from lots of absence from school he never misbehaves there. Is there any test they can do which shows brain activity because essment on his appearance is not working.