There is a close connection in that both require the collapse of a superposition, and I think understanding one does help in understanding the other.
In the double slit experiment the position of the electron is not measured until it hits the screen, or photographic plate or whatever you're using to view the interference pattern. This means that before the electron hits the screen it does not have a well defined position. It's very important to understand this point. It is not the case that the electron has a position but we don't know what it is - the electron is delocalised over the region between the electron source and the screen and it does not have a more precise position in the usual sense of the word.
When the electron interacts with the screen screen we see it as a point on the screen, so suddenly it has a well defined position. What happened?
Well if the electron was in a superposition of all possible positions on the screen, that means immediately after impact the screen must be in a superposition of all its possible interactions with the electron. In this state the position of the interaction between the electron and the screen isn't well defined. And when you interact with the screen by looking at it, you must go into a superposition of states of seeing the interaction at all possible places on the screen. And when you tell me the result I must go into a superposition of all possible things you could have told me. And so on: the superposition ripples out into the whole universe.
But this isn't what happens. Why not?
At this point opinions differ and there are a whole host of theories about what happens. The commonest are probably the Copenhagen interpretation and the Many Worlds interpretation, but several other views exist as well. I've provided links for these, but be warned that the explanations are all heavy on the maths. However they all agree that while it's easy to keep a simple object, like an electron, in a superposition it gets increasingly hard as the object gets more complicated (in physics speak it has more degrees of freedom).
So you don't see the screen as a superposition because it's far too complicated to exist in a state of superposition for longer than the tiniest moment. Instead you see the interaction of the electron and screen as a well defined spot. Similarly the cat/box/poison is far too complicated to survive as a superposition for any significant time. Instead the cat is always either alive or dead.