Will poltergeist activity produced by someone’s mind attract spirits to that location and perhaps compound the problem?

This is quite true, and as you are seeing intuitively, it is the energy being projected into the environment they will notice. Energy always draws spirits, for this is their life and death mission, to locate sources of energy they can use for their survival. So they will be drawn like moths to a flame with such an energy display and then will use every possible means to penetrate the defenses of that energy source and take up residence as an attachment.