Sexual Dysfunction and ADD

I have read a number of the posts regarding sexual desire and some related to erectile dysfunction related to those with ADD/ADHD. I, however, have a different sexual dysfunction- premature ejaculation. I am in my late twenties now, and the problem first showed itself when I was 22 or 23, but has been prevalent ever since. I have tried therapy, the stop start method, medicine (zoloft), other counseling with my wife, all to no avail. 

My question is, is this something others with ADD have experienced? My wife has been patient and kind, but I know she is frustrated (as am I) and we aren't having very much sex as a result. I am currently treating my ADD with Strattera, but it has not impacted my sexual problem.

Any help is appreciated.