Yeah, this scene really stuck with me as well.  I'm pretty sure the psychiatrist says something like: "On a scale of 1 to 100 rate the positive feeling that you get from gambling", and PSH replies immediately with 100.  The doc then asks him to rate the next highest feeling he gets from anything other than gambling…

Uncle Ant

This is exactly what happens to me whenever I hear "Lola" by the Kinks…"I met him in a swamp down in Dagoba where it bubbles all the time like a giant carbonated soda.  S-O-D-A, soda."

Uncle Ant

If I were a gambling man and wagering on which Survivor contestant would be diagnosed with what DSM-IV condition, I would lay money on Brandon having Intermittent Explosive Disorder