After hitting a two-year low in August, September showed slight improvement. For October, however, the index slid from September's reading of 46.4 to 39.8.
The index uses 1985 as a base year, assigning it a value of 100.
"Consumer confidence is now back to levels last seen during the 2008-2009 recession. Consumer expectations, which had improved in September, gave back all of the gain and then some, as concerns about business conditions, the labor market and income prospects increased," said Lynn Franco, director of The Conference Board Consumer Research Center, in a statement.
"Consumers' assessment of present-day conditions did not fare any better. The Present Situation Index posted its sixth consecutive monthly decline, as pessimism about the current economic environment continues to grow," Franco said.
The monthly Consumer Confidence Index is based on a survey of 5,000 households.
In October, the number of respondents indicating economic conditions were "good" fell from 12.1 percent to 11 percent. The percentage of respondents indicating conditions were "bad" rose from 40.5 percent to 43.7 percent.
The percentage of respondents indicating jobs were "plentiful" fell from 5.6 percent to 3.4 percent, while the number indicating jobs were "hard to get" rose from 47.1 percent to 49.4 percent.