The cases never cease to fascinate: reclusive people trapped by their own accumulations, in rooms made unlivable by floor-to-ceiling heaps of newspapers, books and saved objects — from twist ties to grand pianos.Some pass into legend, like the Collyer brothers, "the hermit hoarders of Harlem," who in 1947 were buried by the piles of urban junk that filled their four-story Harlem brownstone. But even less extreme examples, like that of the Bronx man rescued on Monday after being trapped for two days under an avalanche of magazines and catalogs, haunt the public imagination.Such compulsive hoarding is being recognized as a...