Your likelihood of success is going to depend on what program directors think after they hear the "full" story.
To leave training in the midst of PGY4 year and then remain out for 7 years is highly unusual. You have your right to medical privacy / HIPAA, but the practical reality is that you are going to need to be pretty open and forthcoming with them about your disability history for anyone to seriously consider "taking a risk" on you. Programs, state licensing boards, and hospitals are allowed to ask you some fairly detailed questions about your health in order to determine if have any cognitive or physical impairments that could impact your ability to train, perform, and safely care for patients. They'll also be very curious about what you've been doing with your time for the past 7 years. As well as what your former program thought of you prior to you leaving.
Scenario A: You had a cancer diagnosis and spent the past several years undergoing treatments and are cured / in remission and looking to finally move forward again? I think you'd have a pretty high chance of success, especially if you have strong recommendations from your last program.
Scenario B: Your disability was narcotic addiction, and you resigned / entered treatment program after getting caught diverting. I'd say very few anesthesia programs would consider you, although you may have a reasonable shot at starting over in a different specialty if your disease has remained in remission.
Scenario C: You had a detailed history of serious performance and professionalism issues at your last program. They were on the verge of firing you. You are sent to a psychiatrist and receive a diagnosis of bipolar disorder or MDD or something. You ultimately decide to resign from your program. Maybe it was your choice, or maybe the program told you that you could either resign voluntarily or be fired. You've received extensive treatment and therapy, and are in a much better place now. ... this one is tricky, and sadly your chances are probably pretty grim (whether that's fair or not). You are probably seen as high risk with a major red flag. A lot will depend on the specifics like what you've been doing with your time, if you've gotten into any additional trouble in the past 7 years, and if there is anyone at your old program willing to go to bat for you.
There are a million other possible scenarios here, and any additional advice will depend on the details. You are not obligated to share all those details with programs, but the reality is that you will need to be pretty transparent if you are serious about reassuring them about your history.
I also agree that in all reality you are probably looking at starting over again, at least in an advanced / PGY2 or R1 spot somewhere. After a 7 year hiatus (will be 8 years assuming you are looking to start next July) I highly doubt any program will take you as a PGY4 and then graduate you 12 months later. Also, did you even take the Basic exam? I don't think it was out by 2012 or 2013 or whenever you were finishing CA-1. So you'll have to go back and satisfy that requirement, too.
You've clearly been through a lot. Wish you the very best luck.