The same digital screens that have helped nurture a generation of insomniacs can also help restore regular sleep, researchers reported on Wednesday. In a new study, more than half of chronic insomniacs who used an automated online therapy program reported improvement within weeks and were sleeping normally a year later.

The new report, published in the journal JAMA Psychiatry, is the most comprehensive to date suggesting that many garden-variety insomniacs could benefit from the gold standard treatment — cognitive behavior therapy — without ever having to talk to a therapist. At least one in 10 adults has diagnosable insomnia, which is defined as broken, irregular, inadequate slumber at least three nights a week for three months running or longer.

“I’ve been an insomniac all my life, I’ve tried about everything,” said Dale Love-Callon, 70, a math tutor living in Rancho Palos Verdes, Calif., who recently used the software. “I don’t have it 100 percent conquered, but I’m sleeping much better now.”

Previous studies have found that online sleep therapy can be effective, but most have been smaller, or focused on a particular sleep-related problem, like depression. The new trial tested the digital therapy in a broad, diverse group of longtime insomniacs whose main complaint was lack of sleep. Most had used medication or supplements over the years, and some still did.

“These results suggest that there are a group of patients who can benefit without the need of a high-intensity intervention,” like face-to-face therapy, said Jack Edinger, a professor in the department of medicine at National Jewish Health in Denver, who was not a part of the study. “We don’t know yet exactly who they are — the people who volunteer for a study like this in first place are self-motivated — but they’re out there.”

In the study, led by researchers at the University of Virginia, doctors recruited 303 people ages 21 to 65 over the internet. Half were randomly assigned to receive education and advice on insomnia — a digital “placebo,” of sorts, though an active one, in that such advice often helps people sleep better. The other half got a six-week focused online therapy product, called SHUTi.

Some of the researchers, as well as the university, have a stake in this product, which costs $135 for 16 weeks of access. None of those connected to the company analyzed the data or had access to it, or participated in the data analysis, said Lee Ritterband, the lead author and a developer of the online therapy.

SHUTi is not the only digital insomnia therapy product on the market. Sleepio, which costs $300 for a year’s access, and is offered by a London-based company, also incorporates cognitive therapy. And it was also found in a randomized study to have good results.

Both incorporate the techniques of cognitive behavior therapy for insomnia, an approach therapists have been using successfully for years. Some of those techniques date back decades. One is called sleep restriction, in which people set a regular “sleep window” and work to stick to it. Another is called stimulus control, an attempt to break the association between lying in bed and activities like streaming video and eating.

Finally, the therapy aims to undermine self-defeating assumptions about sleep, like “Without a good night’s sleep, I can’t function the next day” or “Medication is probably the only solution to sleeplessness.” The program prompts people to log in daily and record each night’s sleep in some detail; it then tailors weekly sessions based on those entries.

Ms. Love-Callon’s problem, for example, was waking up too early, at 4 a.m. or thereabouts. The online program, she said, instructed her to get out of bed when that happened, and sit and read for 40 minutes — which is more likely to induce sleepiness than, say, shopping online. “And it has worked,” she said. “I get drowsy while reading and have been able to go back to bed and fall asleep.”

The research team tracked the participants, assessing their sleep quality every several months, using standardized questionnaires. After a year, 57 percent of the people using the online therapy program were sleeping normally, compared with 27 percent of those who had gotten only advice and education.

“We continued to see improvement from the six-month assessment through the end of the year, even though people had stopped using the program,” Dr. Ritterband said. “So, that’s a very good sign.”

According to Dr. John Torous, co-director of the digital psychiatry program at Beth Israel Deaconess Medical Center and Harvard Medical School, there are about a dozen online programs on the market using cognitive behavior therapy techniques — for a variety of conditions, including depression — which also have rigorous evidence behind them.

“There are maybe ten thousand or so mental apps out there, and the number is increasing way faster than the evidence base,” Dr. Torous said, “so it’s good to see someone doing careful studies.”

Dr. Torous said the one caveat for all of them is adherence. “When you stop paying people to be in a study, when they stop getting reminder phone calls, they often stop doing it,” he said. “It’s like a gym membership that way; people may do it twice and then let it go.”

Nonetheless, the potential of online therapies to reach huge numbers of people makes it likely that they will become first-line therapy in many cases, some experts say.

“Despite reasons for restraint, it seems inevitable that internet CBT-I will be increasingly used as a first-line insomnia intervention,” concluded an editorial accompanying the study in the journal. “It also seems likely that the medical community may have little influence on whether, when, and how this occurs.”