>>1 Cronenberg wanted to make a movie about mental illness, but no one would have watched it, so he made a horror movie about a fly-man. People would go out to watch that. The degradation of Goldblum's character symbolizes the depth and horror of mental illness. That is what was intended.
However, it wasn't exactly clear, so most people didn't take it as that. I certainly didn't the first time I saw it, but watching it again with that in mind, I see now and make the connection. I think I gave it a lot more credit when I watched it the second time; the first time I thought it was just a stupid horror movie.
A good film all-around.