Too much tech time could be chipping away at teen girls’ self-esteem.

Increased social media use around age 10 can lead to diminished well-being a few years down the road, says new research conducted by University College London and the University of Essex — but only for girls. The study drew upon a survey of nearly 10,000 U.K. adolescents aged 10 to 15.

The researchers found that girls were more prone than boys to spending significant lengths of time on social media — at 13, about one in two girls spent more than an hour on these sites every day, and the gap held throughout later years of adolescence. And as their social media use increased throughout adolescence, their well-being declined. Well-being was measured by how happy they are with their lives, plus any emotional and behavioral problems they have.

While boys’ well-being also decreased, the researchers didn’t find the same association between their well-being in adolescence and social media interaction.

Research suggests that staying glued to screens could be making teens more depressed. A recent study from San Diego State University analyzed data from the Monitoring the Future survey, which asked more than a million eighth, 10th and 12th graders about how much time they spend on smartphones, tablets and computers. It also quizzed them on their face-to-face interactions and their overall happiness. And it found a correlation between increased screen time and increased unhappiness in the kids addicted to their devices, compared to the teens who spent more time on non-screen activities like sports, reading newspapers and magazines and IRL social interactions.

Parents shouldn’t completely pull the plug just yet, however, even if that were a realistic option. Total abstinence didn’t lead to happiness either. In fact, the report found that the happiest teens used their digital media just under an hour per day. That’s a fraction of the nine hours a day the average U.S. teen spends on screens, according to Common Sense Media.

“The key to digital media use and happiness is limited use,” said the study’s lead author and San Diego State University professor Jean Twenge, in the report. “Aim to spend no more than two hours a day on digital media, and try to increase the amount of time you spend seeing friends face-to-face and exercising–two activities reliably linked to greater happiness.”

But when it comes to policing kids’ smartphone use, parents have been left to their own devices.

Bronx mom Tamara South bought her son an iPad when he was 1, and has spent the six years since teaching him how to use it responsibly. Or trying to, anyway.

“We sat with him and played educational apps, and at age 4, he skipped preschool and went straight into kindergarten, which I attribute in part to the iPad,” South, 36, told Moneyish. “But he (7) and my daughter (4) have become obsessed. It’s so easy for them to zone out on it – just as it is for adults – and now when they wake up in the morning, it’s the first thing they try to grab.”

She’s set up their tablets to only access educational games and family-friendly video players like YouTube Kids. They can play on the iPads for just one or two hour blocks, and the more they fuss when time is up, the longer they have to wait until they get them back.

Once upon a time, kids begged Santa for toys. Now they want tablets. “It’s almost like they are born already knowing how to swipe a smartphone,” mused Long Island mommy blogger Shermain Jeremy, 36. The single mother of two girls ages 18 months and 3 years told Moneyish that her mother just gave the kids Amazon Fire tablets for Christmas. “Now I have an 18-month-old who barely says ‘mama’ asking for her tablet with clarity. She’s only had it a month, and she already knows how to swipe and tap.”

Putting the devices out of sight put them out of mind (for now) and South activated the parental controls so that the girls can’t go online or watch anything besides “Frozen” and “Paw Patrol.” She also set the tablets to switch themselves off after an hour. “But I’m already worried about when it won’t be this easy to control them,” said South. “I’m hoping the programmers get more savvy with security parameters, because there’s only so much that we can do as parents.”

Parents can use all the help they can get in monitoring kids’ digital media use. (bowdenimages/iStock)

Help is on the way. Two Apple investors recently refreshed the ongoing screen time debate by publishing an open letter calling on the company behind the iPhone and the iPad to address childhood cell phone addiction.

“We believe there is a clear need for Apple to offer parents more choices and tools to help them ensure that young consumers are using your products in an optimal manner,” read the letter written by Jana Partners LLC and the California State Teachers’ Retirement System, which together own a reported $2 billion stake in Apple.

The average American teen gets his or her first smartphone at age 10, and spends more than 4.5 hours a day on it – and that doesn’t include texting and talking, according to Common Sense Media. Half of the surveyed teens also reported feeling “addicted” to their phones, and compulsively checked them at least once at hour.

And it’s telling that even the masterminds behind these devices have limited how much their own kids play with them. Late Apple founder Steve Jobs told the New York Times in 2010 that he didn’t let his children use iPads. Microsoft founder Bill Gates cut back his then 10-year-old daughter’s screen time to 45 minutes a day in 2007 to rein in her Xbox 360 gaming marathons.

We’re still learning about the physical and psychological fallout from being plugged in 24/7. The investors’ letter cited research by San Diego State University professor Jean Twenge, author of “iGen,” which found that screenagers who spent three hours a day or more on devices are 35% more likely to have a risk factor for suicide — and those spending five hours or more are 71% more likely — than those spending less than one hour glued to their screens.

Read also: The sad effect screens and smartphones have on young women

Harvard researchers have also found that teens who spent five hours or more on screens outside of school each day were more likely to be obese and practice poor health habits linked with obesity, such as drinking sweetened beverages, not getting enough sleep and being inactive. Plus, there’s some evidence that interacting with people solely through social media actually hurts social skills. A 2014 University of California, Los Angeles study found that sixth graders who were separated from their devices at an outdoor camp showed “remarkable improvement” in reading the emotions in people’s faces after just five days offline.

Apple, which made $48.35 billion in profit in fiscal 2017 largely backed by sales of iPhones, including the new iPhone X, has responded that parents can already control and restrict content on iOS devices, as well as manage cellular data, password settings and other features to block what a child could download or access online.

“Apple has always looked out for kids, and we work hard to create powerful products that inspire, entertain, and educate children while also helping parents protect them online. We lead the industry by offering intuitive parental controls built right into the operating system,” Apple said in a statement to Moneyish.

For example, the Family Sharing feature lets an organizer (mom or dad) review and approve or decline all downloads and purchases that up to six family members make by turning on the Ask to Buy setting.

But parents and health providers remain concerned. Children in 1970 began watching TV at 4 years old, according the American Academy of Pediatrics. Today, tots as young as 4 months are already tapping tablets. And these digital natives are spending seven hours a day on TVs, computers, smartphones and other electronic devices by the time they reach school. This digital shift has happened so quickly that the studies are still just scratching the surface of what the long-term impact could be.

“Parents are fighting a losing battle to the tech companies that are designing games and social media that feeds into addiction,” child and adolescent psychologist Dr. Jodi Gold, author of “Screen-Smart Parenting” told Moneyish. In fact, the World Health Organization has proposed labeling “gaming disorder” as a mental health condition for the first time this year.

Read also: Video gamers react to WHO potentially adding ‘gaming disorder’ to its mental health conditions

But screens have become so integrated into every aspect of our lives that it’s not realistic for most parents to pull the plug completely. Dr. Marika Lindholm, a mother of five and founder of Empowering Solo Moms Everywhere, had to give her 12-year-old daughter a smartphone because her tennis coach communicates with students over WhatsApp.

“The rules are completely different for parenting these three younger ones (ages 12, 13 and 14), compared to parenting the older ones (20 and 22),” she told Moneyish. “Now they absolutely need these devices for school. All of their work is done through these online portals. It’s amped up the challenge of being a parent.”

She’s decided that her tweens are only allowed to use phones, tablets and computers at a docking station in the main part of the house, where she can see what they’re doing. “No screens in the bedrooms,” Dr. Lindholm said. She also has relatives, fellow parents and her two grown children help monitor the tweens’ social media activity. And she goes through their phones once a week to see what they’ve been posting, watching and playing.

“I sat down with them to watch ‘Screenagers’ [the 2016 documentary delving into how technology impacts kids’ development and self esteem] and they got the message. My 14-year-old went off of Snapchat for a month,” said Dr. Lindholm. “But I still find things, like one kid posting a video of herself dancing in a towel on Snapchat, or making stupid poses she’s seen grown women doing. And it’s daunting.”

Parents can use all the help they can get in monitoring kids’ digital media use. (patat/iStock)

Apple has responded to the recent backlash by promising to do more. “We have new features and enhancements planned for the future, to add functionality and make these tools even more robust,” Apple added in its statement to Moneyish. “We are committed to meeting and exceeding our customers’ expectations, especially when it comes to protecting kids.”

The Apple investors’ open letter proposed that the company could enhance its software to allow parents to easily child-proof their kids’ phones. “For example, the initial setup menu could be expanded so that, just as users choose a language and time zone, parents can enter the age of the user and be given age-appropriate setup options based on the best available research including limiting screen time, restricting use to certain hours, reducing the available number of social media sites, setting up parental monitoring, and many other options,” it read.

Parents have some suggestions, as well.

“I would love a quick point of reference to see how often a kid was on [a device, app or game], how long they were using it, what kind of stuff they were doing on it – or even something that dinged me if foul language was used,” said Dr. Lindholm.

Jeremy would like more GPS tracking to keep tabs on where her children are using their devices, and said it would be useful to remotely turn her kids’ devices off. “We need to stay a step ahead of whatever you think your kid may do that could be dangerous, and to think of countermeasures,” she said.

This article was originally published on Jan. 10, 2018 and has been updated with new research.