Sounds like a tough time for you both, have you tried approaching your GP or a contact at CAMHS about joint counciling? It sounds like you need to work on the communication between you, it might not stop his teenage rebellious streak but it may well help you to understand him and allow him to feel like he can be more open with you. Hope you don't have too much of a hellish summer hols, and that mabe someone with some experience will come along to give you some more advice.
My 15 yr old DS, (soon to be 16) is becoming increasingly difficult to live with. He has a history of depression and has been through counselling at CAMHS three times during different stages of his development. I had severe postnatal depression when he was born, which I think has caused attachment issues between us. I also have a 17 year old that has done really well in school and is now gainfully employed and generally a pleasure to live with. My DS challenges everything you say to him, and looks for arguments in every conversation. He blames me whenever anything goes wrong in his life, although he constantly makes reckless and stupid decisions. We moved area as where we lived before, drugs were common amongst young people and I know that he has experimented. It is the first day of the 6 weeks holidays, and he has disappeared for the day, reappearing at 9.30pm at night and I know he has been with these old friends. He constantly lies about where he is and I pay for a mobile phone contract for him, he switches it off all day. He has informed me that the police have performed 'stop searches' on him before and I am terrified he will get caught with something he shouldn't have. I have stopped giving him money but he is popular and I'm worried that his friends will just buy stuff. I work full time and am worn out, I am on beta blockers for anxiety as this behaviour has been going on for years. He is aggressive, disrespectful and recently spat in my face during an argument. I am terrified of enduring 6 weeks of him going missing (he has been missing overnight on a couple of occasions) or just generally doing what the hell he wants regardless of what we say. Any help/ advice would be greatly appreciated. I am new to this site but already feel slightly encouraged that I am not on my own in feeling like the world's worst parent!