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 prevalence of misuse was found 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.
The findings were published online December 17 in Psychiatric Services.
"Relatively Little" Knowledge
"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.
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 misuse 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 misuse 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.
Moreover, they were asked about the specific manner of misuse, including: without a prescription; more frequent or larger doses than prescribed; longer than prescribed; or any other use than as prescribed.
Participants were also asked about reasons for misuse, such as "to relax," "to experiment," "to get high," " for sleep," and "for emotions."
Respondents were asked about their source of the misused medication, such as from their clinician, a friend, or a relative.
In addition, information on respondents' self-rated health; past-year presence of a major depressive episode, suicidal thinking, and mental illness; and past-year alcohol, marijuana, heroin or opioid use/dependence and use of tobacco products was included.
The researchers also collected sociodemographic information, including age, sex, race/ethnicity, and household income.
Prevalence of Use
Between 2015 and 2016, an estimated 30.6 million adults used benzodiazepines (95% confidence interval [CI], 29.7 – 31.5 million), which translated into an overall prevalence of use of 12.6% (95% CI, 12.2% - 12.9%).
The prevalence of misuse was 2.2% (95% CI, 2.0% - 2.3%) and prevalence of use as prescribed was 10.4% (95% CI, 10.1% - 10.7%).
The highest use was found among adults between the ages of 50 to 64 years.
In the adjusted logistic regression model, being female, an older age, having more education, and being non-Hispanic white were all associated with increased odds of use.
Several factors were associated with increased odds of any benzodiazepine use, including the presence of past-year mental illness; worse self-rated health; and past-year use, misuse, or abuse of (or dependence on) tobacco, alcohol, marijuana, heroin, prescription opioids, or prescription stimulants.
At every level and among all substances, prescription opioids (either use as prescribed or abuse/dependence) were most strongly associated with benzodiazepine use.
Among respondents reporting any use of benzodiazepines, 25.3 million (95% CI, 24.5 - 26.1) reported use as prescribed by their clinician, while 5.3 million (95% CI, 5.0 – 5.6 million) reported misuse.
Use as prescribed was highest among those ages 50 to 64 years, while misuse was highest among the youngest adults and decreased with age.
Most benzodiazepine use among respondents between ages 18 to 25 years was misuse (5.2%; 95% CI, 4.8% - 5.6%), vs misuse reported by those at least 65 years of age (0.6%; 95% CI, 0.4% – 0.8%).
Female sex and having a "health self-rating" of fair or poor were associated with lower odds of misuse, while any level of marijuana or alcohol use was associated with increased odds of misuse.
Taking prescription opioids as prescribed was associated with lower odds of benzodiazepine misuse, while opioid misuse/abuse or dependence were the characteristics most strongly associated with benzodiazepine misuse.
The most common type of benzodiazepine misuse overall was use without a prescription, although this type of misuse was less likely to be reported by respondents 50 years or older, as compared with younger adults between the ages of 18 and 49 years.
Older respondents were also more likely to report using benzodiazepine more often than prescribed.
"Older adults, age 65 and above, have high rates of use, which is not new, but little misuse," Maust said.
Moreover, "use among adults ages 50 to 64 is now similar or even greater than use in adults age 65 and older, which is new," he added.
Friends, Relatives as Suppliers
The most common reason respondents gave for benzodiazepine misuse was for relaxation or relief of tension, followed by assistance with sleep. In particular, older adults were significantly more likely than younger adults to describe sleep assistance as a reason for misuse and much less likely to report "getting high" as a reason for misuse.
In both younger and older respondents, the most common source of the misused medication was from a friend or relative.
When all sources of benzodiazepines — free, bought, or stolen — were combined, a friend or relative was the source for nearly 70% of respondents reporting misuse. A single clinician was the next most common source.
The most common benzodiazepine misused turned out to be alprazolam (Xanax, Pfizer), although older respondents were more likely to misuse lorazepam (Ativan, Pfizer) or diazepam (Valium, Genentech) compared with younger respondents.
Among respondents with benzodiazepine misuse, 4.6% (95% CI, 3.7% - 5.6%) and 6.8% (95% CI, 5.6% - 8.2%), respectively, met criteria for past-year abuse and past-year dependence.
Maust emphasized that misuse includes "using your friend's Xanax, and it's almost always Xanax, or using your own Xanax more than you are supposed to, for example, at a higher dose or for longer than prescribed."
This medication has a short half-life and high potency, therefore "it is no surprise that close to 75% of misuse respondents report using Xanax," he said.
"Paints a Contemporary Picture"
Commenting on the findings for Medscape Medical News, Anupam B. Jena, MD, PhD, associate professor at Harvard Medical School, Boston, Massachusetts, said that the "main contribution of this study is that the data are recent and paints a contemporary picture of benzodiazepine misuse and the prevalence of concurrent use with other controlled substances, like opioids and stimulants."
Jena, who was not involved with the research, noted that patients who receive more fragmented care from multiple providers "are more likely to receive benzodiazepines and opioids concurrently, and it's not clear if this is because patients seek out multiple providers, or if providers are simply unaware of what other providers are prescribing."
He added that there is "a lot of focus on how prescription drug monitoring programs affect opioid use, but we know less about the impact of these programs on other controlled substances."
Also commenting on the study for Medscape Medical News, Christopher N. Kaufmann, PhD, assistant professor in the Division of Geriatrics and Gerontology, Department of Medicine, University of California San Diego School of Medicine, said there "have been numerous efforts in the past decade to decrease benzodiazepine use in older adults, with some success."
However, "as this younger cohort [age 50 to 64 years] age, these efforts might be stifled," said Kaufmann, who was not involved with the study.
The findings "highlight how important it will be to disseminate and encourage use of safer behavioral treatment for sleep and anxiety disorders in this aging cohort," Kaufmann said.
The investigators agree. "At the policy level, more widespread insurance coverage and access to behavioral treatments may reduce benzodiazepine use and misuse," they write.
The study was funded by the National Institute on Drug Abuse. The study authors, Dr Kaufmann, and Dr Jena have disclosed no relevant financial relationships.
Psychiatr Serv. Published online December 17, 2018. Abstract
Medscape Medical News © 2018
Cite this: Benzodiazepine Use, Misuse Spike in the US - Medscape - Dec 20, 2018.