Seligman documents the connection between learned helplessness, depression, and one’s “explanatory style,” that is, how we explain adversities and fortunate events in our lives. The Wikipedia entry on the book has a good summary.

In the last chapter Seligman discusses the role of excessive individualism in what he calls an epidemic of depression. He says that to be happy, people should look more to their communities, that is, have their life “be about something” beyond, paradoxically, their own happiness. This sounds plausible, and he’s not the first to say this. However, the preceding chapters did not relate any empirical evidence for this conclusion. Rather, they summarized many fascinating studies showing the power of optimistic explanatory style in fending off depression. Perhaps I should look at this more closely, as his recommendations for committing time to the “common good” seem to come out of left field.