Portia seems to panic alot

I notice in a lot of episodes like "so Happy together" the part when Portia freaks out when that guy at the dog show said "that's not a dog it's a rat!" Also the episode when they are camping Portia goes off screaming in the woods, and the episode "the Aprentice" she goes in a fetal position when Bessie "prechewed" their lunch, that is pretty gross but Portia seems to get out of control easily, she definately seems to have some mental problem.