While it does not come straight out and say this, I found traces of PTSD in "The Metamorphosis".  In many of the readings we have covered this semester such as The Sun Also Rises and Testament of Youth, there is a sense of disconnect and unreality that can be attributed to PTSD symptoms.  This is no different in "The Metamorphois".  PTSD caused a barrier between the person suffering and everyone and everything else around them as well as from themselves much like when Gregor is beginning to transform into a bug.  One day, everything seems fine, and then the next he wakes up and finds himself unable to function as he once did.  His body is something completely different and foreign from what he was used to.  He has become a stranger to how his own body works.  He slowly begins to lose the capability to communicate with his family.  He has no way of staying connected with those who did not face the stresses he did of keeping a family together financially.  Even though he had lost the ability to communicate and still could not fully grasp how to manuveur in his new body, he still tried to go on with his day as usual.  He was trying to figure out how he could catch a train and go to work, despite what had happened.  This is also very reminiscent of post WWI times and PTSD.  Even though life seems unreal, foreign, disconnected, and hopeless it still goes on.  New day after new day will continue to come and go so you must find a way to cope with that.