People who misuse prescription painkillers are much more likely to get the drugs from family and friends than from a doctor, a new study suggests.

The study, published in the Archives of Internal Medicine, found that just one in five people who misuse opioids get the medicine only from doctors, and 69 percent never get any opioids from a medical source.

Time reports that the findings come from the National Household Survey on Drug Use and Health, a yearly survey that interviews thousands of people about their drug habits. The survey found that 77 percent of survey participants ages 18 to 25 received painkillers only from nonmedical sources, compared with 52 percent of those older than 50.

The survey also found that 80 percent of people in the survey who said they misused OxyContin had previously used cocaine. This suggests that their addiction was not likely initiated with legitimately prescribed opioids, the article notes.