Are self-reflective people more depressed?

I've repeatedly heard in psychology seminars the truism that introspection (versus extroversion) correlates with depression. Grossmann and Kross, in their comparison of University of Michigan and Moscow State University students, show that this depends very much on culture. Gilbert Chin does a nice summary in the July 30 Science Magazine (picture credit: Vassilij Grivorovi Perov):

Dostoyevsky. For anyone steeped in the traditional canon of Western literature, his name elicits visions of bleak winters filled with contemplative despair. This common perception of Russian culture has fueled speculation about an underlying symbiosis between a predisposition to focus on negative feelings or experiences and a tendency toward depression. Grossmann and Kross have examined this purported linkage by contrasting self-reflective measures in Russians and Americans. Brooding correlated positively with depressive symptoms in University of Michigan students, but these were inversely related in students at Moscow State University even though the latter displayed a much greater propensity for rumination. Assessing the mode of self-reflection revealed that Russian students were more apt than Americans to examine their feelings from a third-person or observer's perspective, reconstruing the experiential details rather than recounting them from a first-person point of view. Distancing oneself in such a fashion mediated the opposite influences of American versus Russian cultures on the relation between self-reflection and negative affect.