https://www.youtube.com/watch?v=9F2TWZ1xfJI
This video is interesting for what it is—a discussion of how 9/11 is treated by the academic community. It is also interesting because it screams semiotics. At every level we can see the fundamental importance of semiotics and how rational analysis of 9/11 has been sidelined by them. From this, it should be fairly easy to perceive how semiotics affect our perceptions and thoughts on many subjects, including private psychological ones. ABN
American Buddhist Net 
the concept of mental illness is a semiotic invention