By Dennis Thompson
The statistics also revealed that benzodiazepine use among adults is more than twice as high as previously reported, with nearly 13 percent using the drugs within the past year.
Studies from 2013 and 2014 estimated that between 4 percent and 6 percent of adults were taking benzodiazepines, which also include Halcion and Klonopin.
Young adults aged 18 to 25 are most likely to misuse benzos, which are typically prescribed to treat conditions like anxiety and depression, said lead researcher Dr. Donovan Maust. He's an assistant professor with the University of Michigan's department of psychiatry.
"If you look at younger adults, basically misuse was as common as prescribed use, which obviously is kind of disturbing," Maust said.
These results jibe with reports earlier in the year warning that overdose deaths related to benzos have increased exponentially over the past decade, in lockstep with a steady growth in prescription rates.
Benzo-related overdoses multiplied sevenfold between 1999 and 2015, increasing from 1,135 to 8,791 deaths, according to a February report in the New England Journal of Medicine.
There's also a link to America's ongoing opioid crisis. Nearly one in three overdoses caused by opioids also involve benzos, according to the U.S. National Institute on Drug Abuse.
Linda Richter is director of policy research and analysis with the Center on Addiction. She said, "The risk of poisoning from benzodiazepines alone is very high, but is compounded for those who misuse benzodiazepines -- a central nervous system depressant -- along with opioids, which suppress respiration. When combined with alcohol, also a depressant, the effects can be similarly severe."
For this study, Maust and his colleagues reviewed results from the 2015 and 2016 National Survey on Drug Use and Health, an annual nationwide survey funded by the U.S. Substance Abuse and Mental Health Services Administration.
Older adults are most commonly prescribed benzodiazepines. But, Maust said, "We knew almost nothing about how common misuse was among older adults, which is a big gap in our knowledge."
Misuse means using benzos in any way a doctor did not direct, including using the drugs without a prescription, taking higher doses than prescribed, or taking them more often or longer than prescribed.
Overall, about 25.3 million adults said they used benzodiazepines as prescribed during the previous year, and another 5.3 million said they'd misused the drugs, the findings showed.
Researchers were surprised to learn that middle-aged folks aged 50 to 64 now are taking benzos more often than any other age group, with a little more than 14 percent reporting any past-year use.
Previous studies had found the most benzodiazepine use among seniors 65 and older, but this survey reported 13 percent taking the drugs in that age group.
Misuse was most common among young adults aged 18 to 25, with 5.2 percent reporting they'd misused benzos within the past year -- more than the 5 percent in that age group who reported using the drugs as prescribed.
Richter explained that "there is a general misperception among young people that prescribed medications are inherently safer than illicit drugs, which we know is not always true and which the current prescription opioid epidemic has demonstrated to be a potentially lethal misconception."
She added that "many young people turn to these medications to self-treat symptoms of stress or anxiety, in part because clinical therapies and treatments are too costly or inaccessible, are seen as too time-consuming, or carry too much stigma."
In addition, Richter pointed out that "many young adults are underinsured; do not have a primary care physician; feel overwhelmed and stressed by work, school and family or social obligations; and have grown up in an age in which a 'pill for every ill' is the norm."
Misuse of benzodiazepines declined with age, the investigators found: 3.3 percent among those aged 26 to 34; 1.7 percent among those aged 35 to 49; 1.4 percent among people aged 50 to 64; and just 0.6 percent among people 65 and older.
Most of the safety concerns revolving around benzo use had been focused on older adults, Maust said. For example, the sedating drugs increase the risk of falls and fractures, as well as car accidents and memory loss.
These results show that overdose risk should be considered just as strongly, particularly among younger age groups, he noted.
"If I were a clinician, the top of my list for who I would want to address benzo use in would be people who are also prescribed an opioid," Maust said. "Next on the list would be people who drink alcohol, because again the concern with benzos is around other substances or medications that are sedating, and the bad effects when you have multiple things on board that are sedating."
Benzodiazepines are being prescribed far too frequently, given that evidence reviews have shown that benzos are of little to no value in treating anxiety, panic disorders or insomnia, Maust said.
Cognitive behavioral therapy and psychotherapy often outperform benzodiazepines, and the drugs have been shown to actually interfere with the effects of such proven treatments, he added.
"Benzos for anxiety is like opioids for chronic pain. There's a small subset of patients with treatment-resistant conditions where use may be appropriate," Maust said. "The current amount of use way, way exceeds what the evidence would support."
The new study was published online recently in the journal Psychiatric Services.