What is the theme in Naked Lunch by William S. Burroughs?

One of the most unsettling and controversial aspects of Naked Lunch is Burroughs's insistence that the condition of existence he evokes is not just an easily dismissable, thoroughly exaggerated version of an uncommon life pattern exhibited by beatniks, drug fiends, and other counterculture freaks, but a continuous revelation of some fundamental facts of basic human psychology. The narrator, who disarmingly introduces himself in the introduction as "Old Uncle Bill Burroughs," is now fully recovered (he claims) from an addiction to heroin (among other things), and is prepared to offer the reader a sort of retrospective tour of an addict's life.