Gridlock hits and there is nothing wrong, it is not pathological. It is where you are unwilling to adapt to each other and unwilling to confront yourself, then you are trapped in emotional gridlock.
When there are no more easy topics that reduce anxiety, then only the hard ones are left. At this point, neither you nor your partner can reduce anxiety by accommodation, since the fallback positions also increase anxiety.
Accommodating your partner means confronting your own unresolved issues. And rather than confront yourself, you are likely to confront --rather than validate--your partner. Many people would rather fight with their spouse than fight with themselves.
Gridlock is part of the sequence of the differentiation process. When we pick a partner, dependency on the other-validated intimacy, a reflected sense of self, and regulating anxiety through the relationship occurs.
Typically the differentiation process begins by emotional fusion: sexual boredom, low sexual desire, lack of intimacy, fights about money, parenting, in-laws--and where to spend the next vacation.
The particulars of what triggers your differentiation are personal and custom-tailored to your past, present and anticipated future. When reaching gridlock, truly validating your partner means accepting that he or she is less likely to accommodate you--and you will have to confront yourself and become more differentiated.
Gridlocked couples experience themselves as falling "out of love."
Ironically, the ability to love doesn't truly develop until the honeymoon is over and gridlock arrives.
Gridlock drives you closer to your own core as it nudges you towards differentiation. And as you get more firsthand experience with your own essence, you become more accepting of everyone else, including your partner.
Passionate Marriage - David Schnarch