At the end of my rope with my 5 yr old boy.
I'm sure there is nothing diagnosable wrong with him. He is exceeding in all areas at school, the teacher said he is right at the top of his class and his behaviour is impeccable at school with an excellent attention span. He has a delightful personality, friendly, polite, gentle with all children etc. No issues at all. In fact he doesn't engage with rough play with the boys and has a more sensitive nature.
He has always been advanced in terms of his capabilities but at home, emotionally he is all over the place. He provokes and attacks his siblings all day long. He is quite destructive - bashing poles into our internal doors and damaging them, writing on walls/carpet, throwing possessions around/at walls. He screams and gets angry a lot. In the car on a journey he will unbuckle his belt, attack his sibling, throw things in the car, scream that he wants to get out. We struggle to go on journeys because of this.
Is it boredom? And perhaps more than the average child because he is more intelligent than the average child? Does he require more attention and stimulation. He does very well with lots of set activities and one-to-one time but I have to do housework and attend to other stuff. I wondered about boredom because it always happens in the car.
I'm probably not explaining it all very well, but let's just say it's so bad that I've just gone on anti-depressants, my daughter age 10 said she feels so unhappy and is never happy at home, son age 7 seems fed up too, my marriage is on the rocks and I've just increased my hours at work from 2 days per week to 5 days per week so I can pay for holiday clubs through every school holiday and not have him home! I realise how awful that sounds 
Is there some special person who could coach our family though this?? I have read Magic 123 and Calmer Easier Happier Boys. I need to read both again but am struggling to implement things as it all feels so overwhelming.