Most of us hate starting thoughts and sentences this way, but when you were a kid, you didn’t spend all your time indoors or in front of a screen. Kids today—pardon the phrase—have more mental health issues than ever before, and a lot of that comes from stress.

But how do we fix childhood stress? What’s the cause? The culprit isn’t totally clear.

It’s not just time away from cellphones and computers. In fact, it may be about how they spend that time away, and how in control they feel when they’re playing.

All of the safe play and helicopter parenting initiatives may be playing a bigger role than screens. It just depends on who you ask.

We all know that getting time away from screens and routines to go out and run around is good for everyone—not just kids. A little activity not in a chair is good for everything from sleep cycles to critical thinking. Advocating activity has been the cornerstone of Michelle Obama’s First Lady legacy, and one of the major points of discussion in the past decade as obesity rates have increased.

And mental health requires it too.

Here’s the big twist though: a little outdoor time isn’t going to solve the problem—at least not if that time is spent under surveillance. A recent Psychology Today story highlighted the independence, adventurous spirit, risk-taking, and sense of control that children get from unstructured play as important for building healthy adults. It's also, the study says, what’s missing from a growing number of unhealthy childhoods.

The article’s author, Dr. Peter Gray, pointed to a San Diego State University study authored by Dr. Jean Twenge that tested for a sense of control among participants and compared it to the past few decades. Kids who have a sense of control “are more likely to get good jobs that they enjoy, take care of their health, and play active roles in their communities—and they are less likely to become anxious or depressed.”

What they found was a severe shift from one side of the scale to the other.

Twenge, a professor of psychology at San Diego State University and the author of Generation Me, explains that her results suggest the problem might be worse in one specific way: kids might not understand that their levels of anxiety and unhappiness aren’t normal.

In recently conducted survey results, “12th-graders are now more likely to say that they have trouble sleeping, that they have headaches, that they have trouble remembering. These are all things that are psychosomatic symptoms of depression. Most people don’t realize that these are symptoms of depression, but they are,” Twenge told The Daily Beast.

“It’s this interesting picture where they’re more likely to say they’re happy, but there are more mental health issues showing up.”

Twenge wouldn’t proffer any specific theories about why kids have more mental health issues, but she says any of a dozen factors could be partially at fault. What’s more, she explains that it’s hard to test for things retroactively

“You can’t randomly assign people to grow up in different time periods,” she explained. “Given that, all you can do is look at the pattern of change: when it started, when it accelerated, maybe when it plateaued.”

Could it be technology? Screens? Sure. And if you listen to experts, it’s probably a contributing factor, if not a major one. Twenge says there are “lots and lots and lots of possible causes. There’s a lot we still don’t know about the effects of screens on kids.”

But those cultural shifts matter, too. Twenge’s research shows a decline in mental health since the 1950s, long before the Internet, video games, or cellphones entered the space reserved for playtime. TV could be part of that equation, too, but Twenge’s best guess wasn’t an object, or even a parenting style—it’s a cultural shift toward individualism.

That would account for the increased anxiety about the future. It would also account for a lost sense of control for many children and young adults—a very important part of the overall happiness equation.

The problem with feeling out of control is that it doesn’t just make someone feel inadequate or anxious. It puts the ability to establish the terms of “success” squarely in someone else’s hands.

In the Psychology Today story, Gray points to Twenge’s research for his explanation: “Twenge cites evidence that young people today are, on average, more oriented toward extrinsic goals and less oriented toward intrinsic goals than they were in the past,” he explained.

For example, an annual poll of college freshmen shows that most students today list “being well off financially” as more important to them than “developing a meaningful philosophy of life.” The reverse was true in the 1960s and 1970s.

This is all very abstract, but it has a root in the way we talk about success. And consequences. If success is about finding something you’re good at, everyone can succeed somewhere. If we shift the conversation to money, there’s a very specific set of parameters—and a specific measure of failure.

Failure, danger, and aversion to risk are becoming the center of the conversation, and it really does start at the playground. Consider the “safe” playground: a structure that takes the risk out of the equation.

Yes, fewer children get injured. Yes, fewer parents worry. But maybe we’re preventing the wrong anxieties by helping parents rather than kids.

So screens may cause their own problems, but as far as mental health at early stages goes, the biggest concern appears to be keeping kids from getting up, getting creative, and doing stupid things. Same for helicopter parenting, bland adventure-less playground equipment, and constant supervision.

So what can parents do right now? It’s unclear what the steps are, since there isn’t data to really explain the perfect solution. But turning off the TV and kicking the kids out of the house may be part of the solution… just so long as they don’t spend that time on their phones.