I'm curious: to what extent do the "seven deadly sins" cover the most common reasons why people engage in self-defeating behavior?

One of the most interesting sins in this context is "acedia," which is commonly misinterpreted as "laziness." It seems like "depression," seen by moderns as a psychological disorder, is a much closer concept.* If you asked a psychologist for the 'most common reasons people engage in self-defeating behavior,' they would likely start at a list of disorders, and depression typically tops the prevalence lists.

But it doesn't seem to me that other disorders match up well to the sins, or the sins to disorders. I'll also observe several of the sins seem positively approved of by much of modern culture. Capitalists are fans of greed as a drive, and the sex-positive are fans of lust as a drive.

*Wiki thinks this point is contentious, but I think the contention is only applicable if you get into the fine shades of things, not the coarse clusters.