Dog separation anxiety help

My friend has an American akita, 7 months old. Showing behaviour like ripping up furniture and peeing as soon as the dog sees her when she's left. She has tried giving her dog toys and something to do while she's out but it's no good. The dog is also destroying things that get more attention than him for example a book she was reading.

I know this dog is still a puppy but it's driving her insane and she doesn't know what to do, is there any advice you could give on this matter?