More than 30 million US adults, or roughly 1 in 8 people age 18 and above, used benzodiazepines in the past year with over 5 million reporting misuse, new research reports.

Investigators analyzed 2015-2016 data from the National Survey on Drug Use and Health (NSDUH) and found that almost 13% of respondents reported past year use of benzodiazepine, with only 10% using these agents as prescribed and 2% reporting misuse. Misuse accounted for almost one-fifth of overall use. The highest prevalence of use was found in adults ages 50 to 64 years, while the highest incidence of misuse was seen in those aged 18 to 25 years.

"The focus has been on the badness of benzodiazepine, specifically in older adults, but with growing use in midlife superimposed on the opioid epidemic, this problem is not going away," lead author Donovan Maust, MD, assistant professor of psychiatry, University of Michigan and research scientist, Center for Clinical Management Research, VA Ann Arbor Healthcare System, told Medscape Medical News. "To our knowledge, this is the first national estimate of benzodiazepine misuse among older adults  a surprisingly data-free area," he said.

"Our motivation for conducting the study is that, even though benzodiazepines are widely prescribed, are regulated by the DEA, and adverse events appear to be increasing for example, benzo-related emergency department poisoning and overdose mortality  relatively little is known about the extent of misuse, particularly among older adults who are prescribed the most," Maust said.

Analyzed Data

To investigate this issue, the researchers analyzed data from the NSDUH, a 50-state survey sponsored by the Substance Abuse and Mental Health Services Administration. The NSDUH provides detailed information regarding prescription drug use and misuse in the US, including the type and reasons for abuse and the source of misused medication. Previous NSDUH surveys had limited "misuse" to "nonmedical use," but the updated 2015 definition was revised to include "in any way a doctor did not direct."

The researchers used data from the 86,186 survey participants (at least 18 years in the 2015-2016 survey year) to develop national estimates of benzodiazepine use and misuse among US adults and to understand whether characteristics associated with abuse varied by age. The current analysis was focused only on the respondents (n = 10,290) who specifically reported benzodiazepine use in response to the questions about tranquilizers and sedatives. Respondents were asked about past-year use and misuse.