This is only a theory, feel free to expand on it or whatever.
EJ: When an EJ gets super stressed and starts freaking out, (s)he acts like the worst negative stereotype of an EP. When (s)he gets super depressed, (s)he acts like an IP, except completely lacking inner harmony and a reasonable level of functionality.
IJ: When an IJ gets super stressed and starts freaking out, (s)he acts like the worst negative stereotype of an EP. When (s)he gets super depressed, (s)he acts like an IP, except... depressed.
I attempted to write ones for EP and IP, but I don't think my descriptions were working. Does someone else want to give it a shot?
Anyways, my theory is that one is unlikely to act like even a bad stereotype of their dual's temperament when they're unhealthy.