Consumers were slightly more confident in the economy in September, but are increasingly worried about the future.

The Thomson Reuters/University of Michigan's consumer sentiment index inched up to 57.8 in September from 55.7 in August, according to a Reuters report. The August reading was the lowest since November 2008. Friday's report is a preliminary reading.

But consumers are more pessimistic about their future prospects. An index tracking consumer expectations fell to its lowest level since May 1980.

Americans are more optimistic about present conditions. That component of the index rose to 74.5 from 68.7.

Consumer confidence plunged in August, after the government said the economy barely grew in the first half of the year, lawmakers fought over raising the nation's borrowing limit, and Standard & Poor's downgraded long-term U.S. debt.