21 year old son with mental health problems

Hi, I am new to this forum and have joined because I am living with an adult child who has an undiagnosed mental disorder. He is 21 and not working or learning. He worked in a supermarket and saved over $10K. Since he left that job he has smoked dope, gambled most of the money, isolated himself from friends and basically allowed his dark shadows to control his life. Just recently he agreed to come to the GP with me and was prescribed anti-depressants and advised to get of dope as quickly as possible. He was with HeadSpace but felt that he was not getting anything out of the sessions so stopped going. He has agreed to see psychologist in our local area. I am very grateful for the services available to him.

I just don't understand his negativity. He is a young, good looking person with a terrible attitude to life. I woke up one night in a cold sweat thinking that something terrible must have happened to him that I didn't know about and asked him but he said 'no'. He dropped out of a TAFE course that he started when he left school because he basically couldn't handle adult education and taking responsibility for himself. I broached the idea that he may be suffering with ADD and he agreed telling me that he'd been researching why he felt the way he did.... lost, lonely, sad, a gumby (his words) and that ADD came up as a reason. He was seeing a kinesiologist over the course of a year while he was working and ultimately she told me that his belief system mirrors that of an alcoholic or drug addict meaning that his problems are caused by circumstances that are outside of his control and that he is a victim. That is certainly how he behaves.

He is self aware and is often researching why he feels like he does and has flagged the idea that he is a narcissist and may have an Avoidant personality disorder. His father and I are keeping a close eye on him and supporting him to the extent that he has a safe home, good food, parents who love him and will support him emotionally but it's hard. It's hard seeing him lay in bed all day, complain about life and not try. I have taken away the x-box controllers; I take away any dope or bongs that I find. I read the books with him that the psychologist has recommended and read other books from the library.

The thing he does that drives me mad is agree to do something and then at the last minute tell me that he didn't agree to it at all (avoidance.....or control?) I don't know. This weekend we booked to go away for 3 nights which he agreed to and now tonight he says he won't come. It's upsetting because he has a younger brother who wants him to come. My husband has said that if he doesn't come then none of us will go. I doubt that he will feel any sort of guilt about that. In fact I know he'll just say that it's not his problem. I imagine you're thinking why we would want to take a 21 year old with us anyway but with the way he is it would be irresponsible to leave him at home alone.

I have spoken to a few people who have said that 'it's a boy thing and he'll grow out of it'. I really do hope so. I don't know how to motivate someone who is so determined to live like a victim of his fears. I wonder if any of you have any thoughts, experiences or ideas.