UTEOTW and Synecdoche NY

Has anyone seen both films? I figured there could be an interesting discussion on the similarities/differences in the theme.

The theme I'm referring to is the implosion of the mind when left to its own obsessive nature. In UTEOTW we have the dream machine--"the human soul singing to itself"--which turns people into crazed addicts who give up reality in favour of their mental masturbations. In Synecdoche we have the protagonist, Caden, who embarks on re-creating the story of his own life, and similarly he finds himself trapped in an isolated, warehoused world which closes in upon itself, reducing him to a total zero.

The major difference *SPOILERS AHEAD* is that Wim's world is optimistic, and the protagonist realizes the folly of his pursuit before it is too late. In Kaufman's world, the underlying theme seems to be inevitable nihilism, and the outcome is quite different.

Both are excellent films that hit on a fascinating philosophy. Is the human soul a self-contained unit? Or does it need an envelope of reality in order to exist?