American adults' marijuana use nearly doubled over three years, a new survey finds.

The Gallup telephone poll of about 1,000 adults found that 13 percent said they were current marijuana users and 43 percent said they have tried the drug, CNN reported.

In 2013, those percentages were 7 percent and 38 percent, respectively.

Twenty percent of adults younger than 30 use marijuana, a rate at least double that of older adults. Only two percent of weekly churchgoers use marijuana, compared with 7 percent of those who go to church monthly, and 14 percent of those who seldom or never attend a religious service, CNN reported.

Adults in the West were more likely to use marijuana, which could be due to the fact that recreational marijuana is legal in Colorado, Oregon, Washington state and Alaska.