<textbox fpptsdyes> *is* defined more than once: Lines 346 & 355 in the script.
In addition
/ branch = [if(radiobuttons.fpdep.fpanx.fpbp.fpsch.fpocd.fpptsd.fpoth.response=="Yes: Whom? (indicate below)")surveypage.FamPsychfollowup]
in <surveypage demographics6> is completely invalid. A property such as the one highlighted above does not exist and you cannot string together various elements like that.