A national survey found that the number of people in the U.S. using medications like tramadol, phenobarbital, and amitriptyline has increased from about one in every five people in 2014 to one in 10, according to the results of a recent survey.
The survey was conducted by the National Institute of Mental Health and published on Tuesday.
A survey of more than 1,000 adults also found that more than 40 percent of respondents were either taking tramadulone or phenobarbusone to treat anxiety, according the survey.
Tramadol and phenobarbinone were the top two medications used for treating chronic pain in the United States in the past year, according a recent study by the American Psychological Association.
In 2015, a federal judge ruled that the government had overstepped its authority in its attempt to force Americans to take tramadrol, phenytoin, or amitrexone.