I know from my own experience that chess can be very addictive for some people. The point is that it is no longer providing fun or relaxation anymore, but it becomes a necessary distraction. I would suggest to mrs. B. to try to make her husband aware that it is his own problem in the first place. For his own benefit and wellbeing he should try to get rid of the addiction, because it is not helping him feel better. Try to get him to severely limit daily chess-time, than introduce chess-free days of the week, than chess-free weeks. Let him be prepared that it is a painfull process. Other activities will emerge.
Maarten
A psychologist should be able to help him.