After reading a lot of the postings and after much thinking, I see selfishness and selfcenteredness of ADD afflicted persons as a core reason of the suffering of their spouses.  It is the core reason of my own pain.

I have been wondering, what of the both is more probable:
1. Selfishness is hardwired in the brain as a part of ADD.
2. Selfishness is an independent trait, and it determines, if someone burdens the detrimental effects of his ADD upon others or takes the burden of sparing others upon himself.
Maybe selfishness of the ADD persons drives us devastated posters here, not just ADD?   Maybe a non-selfish ADD person would be much easier to live with?

I am so puzzled, what is behind my SO's selfishness.  I mean, how in his own mind he justifies his selfish acts.   

Here is one incident, when I felt very hurt because of very selfish behaviour:

At one time, I had 4 weeks to spend with him, and we had a lot of conflicts, misunderstandings and disagreements from the previous months of being apart to work on.  I also had it made very clear that the objective of that period was to work on the relationship and to do a lot of talking, and in my perception, he had agreed to this.  
When I arrived, he told me that he has taken on a task, that would bring him no money, but a lot of honor, praise, admiration and attention (That he did not tell me...)All this was obviously more rewarding, more important than to improve the relationship.  He had accepted a deadline for the task during the time of my stay.  I felt very hurt, it was so disrespectful, selfish and inconsiderate.  
But it got worse.  I got a sick from an infection, and the computer broke down, which he needed for his task.  He has no debts, he usually can manage his money, but we are both fairly poor, and we cannot afford extra expenses without renouncing other things.  In spite of this, he wanted to have a working computer immediately.  I know how to repair a computer, but I was weak and sick in bed.  
He threatened to drive to the next shop and just buy one.   To avoid this, I yielded to the pressure and in spite of having a fever went with him to a shop to get parts and help him to get his computer working again.  
He still considers his priorities on that occation as ok, even though he has verbally  apologized, as he does many times for such incidents, when I get upset badly.  But then he makes excuses that are good enough only for himself.  He forgives himself, and wants to be forgiven and leave bygone events behind.  But I refuse to forgive without a change in the attitude, that had caused the hurting behaviour, because he will continue to hurt me for the same reason.  I could forgive him based on the insight and acknowledgement, that he owed it to me to postpone the deadline or refuse that task in favour of giving priority to the work on the relationship.   

I am not puzzled, that he takes on such a task on impulse, that is typically ADD.  But with what going on in his mind can he defend this as being right, how can he consider himselt entitled to such selfish priorities?

Sometimes I suspect, that he just lacks the value of fair exchange in his value system, that he does not feel a bad person, and neither shame nor guilt for being selfish.  I even suspect, that his concept of commitment is limited to not cheating, and sharing a household, but that he does not take upon himself any more ethical obligations like a fair balance between his and my needs, which I can agree upon to be really fair, and the responsability for all consequences of his behaviour upon me, no matter if they were intented or accidental.   

Sometimes I suspect, that he automatically considers it the most natural thing in the world to give priority to his needs and whims, and that it even never occurs to him to justify any of this to himself. As if he feels entitled to selfishness, without consciously defining it as selfish, but more as his natural right.   Following his impulses seems perfectly ok to him.   
(I even had a weird and farfetched thought, how ADD could be explained:  Animals are driven by impulses from instincts.  Humans have the mental capacity to check the external and internal (=justification by own values) consequences of their acts before getting started.  When someone acts on impulse without thinking, then it seems as if he behaves on the same level as an animal.  People, who think before acting are a step ahead in evolution, and that maybe in modern society's gene pool are still some leftovers from bygone times.  Humans and chimpanzees are said to share nearly 99% of genes.  Maybe many, many years ago, normal average people were driven by impulses and selfishness like ADDs today, and today's non-ADDs had yet to develop.  I do not believe in weird speculations, even my own, so please nobody take offense.)

Sometimes I suspect, that he just has a distorted perception of the consequences of his behaviour upon me or keeps himself in willfull ignorance of any painful consequences at all.   He might honestly believe to participate in a fair deal, an even tit-for-tat, while to me his behaviour is hurting and selfish.   

Anyhow, I have come to the conclusion, that I cannot marry him, as long as he is comfortably selfish.   So I printed out a note for him today:

Your intelligence is sufficient to learn to spare me suffering.

It is your decision, which attitude to have:
1. Do you want to be a selfish or a caring person?
2. What value do I have for you, am I a utility or someone deserving care?

Your decision determines your behaviour.
Your decision determines our future.

Has any ADD husband/SO ever made a conscious pledge to stop being selfish?  Did it have any positive effect?