Rumination:Problem-solving gone wrong

Rumination as a problem-solving strategy gone wrong. General article in Psychology Today.

Depression's Evolutionary Roots

An article by Paul W. Andrews and J. Anderson Thomson Jr. in the current (Jan 2010) edition of Scientific American Mind suggesting rumination as beneficial in ending depressive episodes.
Key concepts

The brain’s ability to enter a depressed state has been preserved throughout evolution, suggesting that depression is an adaptation.

Depression promotes focused rumination about problems. People in this state of mind are better at solving complex social dilemmas.

Effective therapies encourage patients to engage in rumination, allowing them to find solutions to their problems and end their depressive episode.

Unfortunately PPV if you can't access it otherwise but you can read a preview here.

Flies in the face of some pretty substantial work suggesting otherwise. Thoughts anyone?