Americans are desperate to get some shuteye.
According to the first government study of its kind, about 9 million U.S. adults resort to prescription sleeping pills to fall asleep — and most are white, female, educated or 50 or older.
But that's only part of the picture. Experts believe there are millions more who try options like over-the-counter medicines or chamomile tea, or simply suffer through sleepless nights.
"Not everyone is running out to get a prescription drug," said Russell Rosenberg, an Atlanta-based sleep researcher.
The Centers for Disease Control and Prevention study was based on interviews with about 17,000 adults from 2005 through 2010. Study participants were even asked to bring in any medicines they were taking.
Overall, 4 percent of adults said they'd taken a prescription sleeping pill or sedative in the previous month.
The study did not say whether use is increasing. But a CDC researcher calculated that use rose from 3.3 percent in 2003-2006 to 4.3 percent in 2007-2010.
That echoes U.S. market research — as well as studies in some other countries — that indicate an increase in insomnia in recent decades.
"Sleep disorders overall are more prevalent than what they were," said Dr. Ana Krieger, medical director of New York's Weill Cornell Center for Sleep Medicine.
That could be due to a number of factors, experts said. Some include obesity-related sleep apnea, the rise of social media and other electronic late-night distractions and financial worries from the recent recession.
Earlier studies have tried to track pill use through prescription sales, but that offered a flawed view.
For adults, the recommended amount of sleep is 7 to 9 hours each night. Previous CDC research suggests at least a third of adults get less than that. Doctors offer tips for good sleeping that include sticking to a regular bedtime schedule, getting exercise each day and avoiding caffeine and nicotine at night.
By some estimates, nearly 10 percent of Americans suffer chronic insomnia and may seek a physician's help. Inadequate sleep has been tied to the start and worsening of a range of diseases and conditions, including diabetes, heart disease, obesity and depression.
The CDC study results confirm some patterns that doctors have been observing for a while. They include:
— Women are more likely than men to take sleeping pills, 5 percent versus 3 percent.
— More whites take pills — nearly 5 percent, compared to 2.5 percent of blacks and 2 percent of Hispanics.
— Prescription use increases with age, to 7 percent of those 80 and older.
The findings may have been influenced in part by who had health insurance and access to doctors who would prescribe sleeping pills, said Yinong Chong, the study's lead author.
But clearly people tend to have trouble sleeping as they get older, due not only to aches and physical changes but also to emotional burdens, experts say.
Retired law professor Jane Kaplan has had trouble sleeping since she was a young woman, but it got worse around 2007. Over a year, her husband, mother and sister died.
She still takes Ambien, a popular sleeping pill, which helps her fall asleep but she wakes up in the middle of the night. It's not unusual for her to get only 3½ or 4 hours.
Kaplan said she's been working with Krieger to deal with her sleeplessness. But it remains a struggle, the 70-year-old said.
"You wake up tired and you just count the hours until the day is over. And you hope tomorrow's going to be better," she said.
Based on reporting by The Associated Press.