In his 2004 book Superman on the Couch, author Danny Fingeroth noted that mental health professionals had written little on the psychology of comics in the 50 years since psychiatrist Fredric Wertham's 1954 book Seduction of the Innocent damaged the comic book industry when he pegged comic books as the leading cause of juvenile delinquency in America. ("I think Hitler was a beginner compared to the comic-book industry," Wertham then told the U. S. Senate.) Fingeroth told me he'd braced himself for people informing him that he wrong, but that deluge never came. He was not wrong. The number of books on the psychology of comic book characters is small - until the past decade, virtually nonexistent.
In the course of compiling a list of books that use psychology to look at comics or comics to teach psychology, I've also found that despite the large number of books in media psychology (the most attention-getting of which tend to gripe about movies, TV, and video games as their scapegoats, akin to the way Wertham blamed comic books), few focus on the psychology of specific books, movies, or television series. These works by psychologists and a couple of psychiatrists look at comic books or specific non-comic stories.
Some self-published works also exist and a list of those could certainly be worthwhile. Self-publishing can be an excellent way to disseminate information and, when done right, potentially much more profitable for the authors. Because they haven't gone through the same evaluation process as the abovementioned books to get published, though, I'd like to know more about them first, so that's a list for another time.
There you have it, our small list of post-Wertham books that apply psychology to comic books and specific entertainment titles. Suggestions for additional entries would be most welcome.