(CNN) -- Baby boomers are putting down the crochet needles and picking up the pipe...the marijuana pipe, that is.
According to a national survey on drug use and health, about 9% of adults between 50 and 64 have used marijuana at least once during the 12-month survey period. And for adults over 65, about 3%.
The study, published in the Journal of Drug and Alcohol Dependence, surveyed nearly 18,000 adults across the country and found that the number of cannabis users has doubled over nearly a decade.
One of the authors says that while marijuana use is gaining popularity with older Americans, most aren't newbies when it comes to pot use or other substances. Nearly 5% of middle-age marijuana users abused alcohol and 3.5% misused opioids.
Among older adults, 1.5% abused alcohol and 1.2% misused opioids.