Lack of Empathy: ADD or something else?

I'm really struggling with something here folks, and I hope there is someone out there who can provide a little clarification. My wife was diagnosed 3 years ago with ADD, after struggling with depression for 10 years before that. I was excited, and, believe it or not, happy to finally have a diagnosis, and a course of treatment that I thought, by all indications and suggestions by her doctor and many other ADD experts, would improve her condition and the quality of our life. She is under medical supervision by one of the best psychiatrists in town, has had neurofeedback therapy, and has worked now for 2 and a half years with an ADD/ADHD only behavioral specialist who has helped her attempt to start to organize and refocus her life based on proven and well known behavioral techniques, in an attempt to improve the Executive Function in her brain. But recently, to his and my alarm, we've concluded that there has been only marginal and temporary improvement. And in some ways, I think she's getting worse. And as she gets worse, so does our relationship. I keep going back over all of the books and literature trying to see if I've missed something in her behavior so I can pass it onto her medical supervisors. Clearly, her behaviors match those that are so well documented in Melissa's and other author's books. But one of the symptoms that affects me and our daughter most, as we interact with her, day to day, is her lack of empathy. She truly struggles with the idea of why my young daughter would be so hurt and angry when she forgot to come home one night while out with with her visiting college buddies, or my being angry when she forgot to take me home after Lasik surgery, or why my daughter doesn't want her to take her to and from school, after forgetting to get up in the morning and pick her up afterwards. You know the story, folks, the hundreds of ADD moments like these that slowly cut to death even the most compassionate of mates. But her apologies just don't sound sincere. They just don't ring from the bottom of her heart. I really don't think she "gets it". (Even our daughter senses it) I've made a concerted effort to try to listen to her voice, body language, eyes, everything....and I've come to the conclusion that she really can't feel us, the other people in her life and how her behaviors affects the rest of us in her world. Clearly, to me at least, there seems to be something else going on here. SO I went back to the drawing board (internet), and researched the symptoms of Aspergers Syndrome and found, among many things, an Australian govvernment sight that described her to a "T". Could this be it?? The one variable I hadn't put my finger on? It's still only a guess, but I reported the idea to her behavioral therapist and he said that it's easy it miss an Asperger symptom as the distracted ADD mind can simply be too overstimulated to reach the depth of compassionate understanding the "non's" may be emotionally expecting. He said he would look into it further and he would consider my theory after some more research on his part. Time and more medical investigation will prove my concern right or wrong. Which brings me to my now well belabored point. (I certainly invite Melissa into this part of the conversation if she is available to comment.) How many people have had Asperger's diagnosed along with their adult ADD? Is this common? And how can a marraige heal/survive if one partner cannot neurologically connect with the other. I've read a lot of stories over the years on this site in which people descibe very similar behaviors of this condition. It also seems to me that this particular disability could be regarded as incompatible with marriage. To my untrained eye, it seems hard to distinguish between some of the symptoms because on some levels, they can seem so incredibly similar. Three years later, I can now easily recognize her ADD symptoms, but I'm now, more than ever, convinced that there is another script be played out here. I'm truly at my wits end. I've given everything I have (time, compassion, health, faith) to this relationship and I have very little left. If you are familiar with "Friedman's Fables" short stories, I'll be the one on "The Bridge". (You can google " Friedman's Fables The Bridge". It's a short, 3 page story about how to set and live with the outcome of setting your most powerful personal boundary) This avenue of investigation is the last chance before I open my hand. I await your thoughts, insights and experiences.