I had two responses to this. I typed out the first one, then reread your post and thought maybe you were saying something other than what I thought the first time. I’ve decided to offer both.
Depends on what you want to say.
Mc- my way of thinking is causing me all sorts of problems
IC-you take action and it inspires me to try
Rs-we can get through this. We won’t quit.
Mc-my actions are very destructive to me and everyone around me
IC-when I look at you I think maybe I need to think differently about some things
Rs-we’re in this together
Mc-All I Can think about is my next fix
IC-you have severe health issues
Rs-your behavior is hurting us
Those are quick and dirty (and probably not great) examples of what I think you could say with those throughlines in different contexts. I didn’t list out the domains I see them taking place in, but I see each of those configurations being aligned differently on the chart. If you see more than one perspective in Psychology, you need to pick one and change the others accordingly.
Can you look at this story as a whole and get a better idea? For instance, if you see Psychology problems as a possibility for multiple threads, can you maybe say that your IC is definitely in one area? Or maybe the OS? If the Os is probably Physics, then yes, put RS in Psychology. If your OS is more of a Universe problem, then you might listen to yourself when you say Psychology is the MCs problem first and foremost.
When you say “IC and MC” do you mean M/I, aka RS? If so...
...Do you mean that Psychology is the MCs personal source of conflict first and foremost (in which case you are telling us you have two perspectives in one domain and need to change something) or could it be that you are saying the MC player and not the IC player looks like the one dealing with the Psych problems that are creating conflict in the relationship (in which case you would have an RS that is experiencing conflict from a problematic way of thinking and would indeed need it to go in Psychology)?