A shocking number of American kids are sad, suicidal and stuck on small screens sucking away their zest for life.

• Why it matters: This is the indisputable and alarming trend among American children, based on the latest polling and deep research by a prominent social psychologist in a book out next week.

🧮 The startling data: Rates of depression and anxiety among American adolescents jumped by more than 50% in multiple studies between 2010 and 2019, writes Jonathan Haidt, a leading expert on the spike in teen mental illness. Those numbers were relatively stable in the 2000s.

• The suicide rate for kids between 10 and 14 tripled between 2007 and 2021, according to the CDC.
• The share of high school girls who seriously considered attempting suicide jumped from 19% in 2011 to 30% in 2021.

Three events are bringing the crisis into sharper focus: the release of the annual World Happiness Report, the congressional debate over TikTok and next Tuesday's release of Haidt's book, "The Anxious Generation."

🖼️ The big picture: The pandemic is often cited as a driver of the teen mental health crisis. But it was brewing long before then, Axios' Erica Pandey writes.

• A growing body of research links the acceleration of the crisis to one of this century's biggest events: the arrival of the smartphone.
• "Smartphones and social media fundamentally changed the way teens spend their time outside of school," says Jean Twenge, a psychologist and author of the book "Generations."

🔎 Zoom in: In study after study, teens say social media is making them stressed and depressed. But the time they're spending online keeps rising.

• In the early 2000s, middle- and high-school kids saw friends in person about three times a week. Now, that's closer to 1.5, according to data from the University of Michigan's Monitoring the Future project.
• At the same time, screen time has skyrocketed. Teens spend an average of 4.8 hours every day on social media apps, including TikTok, Instagram and Snapchat, according to Gallup.
• For the first time, the U.S. fell out of the top 20 in the World Happiness Report, released Tuesday. Gallup cited "Americans under 30 feeling worse about their lives" for the steep drop.

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American teens — by a large margin — use YouTube more than TikTok. But they're more likely to scroll through the ByteDance-owned app "almost constantly," according to Pew Research Center polling.

• Why it matters: The stat points to how addictive and unhealthy TikTok's endless feed of videos can be for teens.

🔭 Zoom in: There's suddenly a roaring national debate over fears about teens' privacy, their data security — and all the misinformation going straight to their phones.

• Citing national security concerns, Congress is pushing to force the platform's Chinese parent company to sell TikTok or face a ban.
• A ban — though unlikely anytime soon — would force a massive shift in how millions of Americans spend their time.
• "It's of course possible that people will replace TikTok time with YouTube time or Instagram time," psychologist Jean Twenge says. "However, TikTok's algorithm is particularly effective at getting you to spend more time on it."

Between the lines: A study from the Center for Countering Digital Hate found that new TikTok accounts were shown self-harm and eating disorder content within minutes of scrolling.

• Suicide-related videos popped up within 2.6 minutes.
• Eating disorder content popped up in 8 minutes.

🥊 Reality check: It's not just TikTok. Teen mental health started to plummet years before the app launched in 2016.

• Top social media companies say they've made efforts to curb the crisis.
• Asked for comment by Axios, TikTok pointed to community guidelines that say: "We do not allow content that may put young people at risk of exploitation, or psychological, physical, or developmental harm."
• A YouTube spokesperson passed along blogs explaining the platform's "expert-backed approaches to eating disorder content and limiting certain types of recommendations."
• Meta said it has "well over 30 tools we have released" to help parents and teens manage Instagram and Facebook.

A huge happiness gap is opening between American adults and teens.

• Depression has hit teens much harder than adults in the smartphone era (charted above), according to National Survey on Drug Use and Health data.

The massive gap is clear in the World Happiness Report:

• In the oldest age group, America was the world's 10th happiest country. Among the young, America fell to 62nd place.

Between the lines: Young people in North America are now less likely to say they're happy than older populations.

• That's a massive reversal from most regions, where younger people tend to be happier.

Don't give your kid a smartphone before high school, and don't let them use social media before age 16, argues Jonathan Haidt, a professor at NYU's school of business.

• Why it matters: Haidt says the shift from "play-based" to "phone-based" childhood is making our kids sick and miserable, Axios' Jennifer A. Kingson writes.

The big picture: "The primary thing that we are trying to understand is why adolescent mental health fell off the cliff right around 2010," Zach Rausch, Haidt's research partner, tells Axios.

• "The core thesis ... is that we started overprotecting kids long before 2010 — it really began in the 1980s."
• "We started pulling kids indoors, giving them much more supervision in highly structured activities and much less independence, free play and responsibility."
• By 2010, "social life for adolescents in particular moved almost entirely onto smartphones and social media platforms, and completely away from this in-person, real-world childhood and adolescence."

The book offers four controversial suggestions:

1. No smartphones for kids before high school — give them only flip phones in middle school.
2. No social media before age 16.
3. Make schools phone-free.
4. Give kids far more free play and independence, including more and better recess.

🥊 Reality check: Putting the cellphones-and-social-media genie back in the bottle is going to be a tough sell.

• Parents are often the ones demanding to be able to reach their kids during the school day.
• They're also the ones pleading with their kids to put the phones down — without success.

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A company called Yondr that sells lockable cellphone pouches is rapidly cornering the market in K-12 schools as educators crack down on texting and social media during class, Jennifer A. Kingson writes.

• Why it matters: Banning cellphones in schools doesn't get students to stop using them there. School districts in at least 41 states have turned to Yondr in hopes the company's pouches will.

How it works: When students get to school, they have to lock their phone (and smartwatch, AirPods, etc.) in a pouch they carry all day.

• When they leave for the day, they unlock the pouch by pressing it against a device near the exit.
• In case of emergency, they can go to the school office to get it unlocked. Some classrooms also have unlocking devices.

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Boredom isn't bad for kids — it actually benefits their development, psychologists say.

• Why it matters: Boredom that leads to unstructured play can curb attention-seeking behavior and inspire creativity, Axios' Carly Mallenbaum writes.

State of play: Making sure kids have "real-world" activities — not just virtual ones — is also important for fostering interpersonal skills.

• When kids play together IRL, they strengthen nonverbal skills like maintaining eye contact, says Kimberly Alexander, a clinical psychologist at the Child Mind Institute.

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For better or worse, high schoolers are participating in significantly less risky behavior than they were three decades ago, Axios' Noah Bressner writes.

• Why it matters: Studies show that Gen Z is more shy than millennials.

Almost every frowned-upon activity has taken a hit among high schoolers, according to the CDC's latest Youth Risk Behavior Survey, from 2021.

• About 23% of high schoolers said they drank alcohol in the last month — down from 48% in 1993.

The percentage of students who said they've ever had sex was down 23 points.

• In 1993, almost 42% of students reported being in a physical fight in the last year. That's down to 18%.

This simple, consistent conclusion emerges from decades of research about what makes us truly happy: meaningful connections.

• Why it matters: That's precisely what so many American kids and teens are missing out on as screen time increases and in-person social time decreases, Axios' Erica Pandey writes.

Some schools are trying to fight the mental health crisis by baking happiness into the curriculum.

• Iowa State has a new class this semester on the science of happiness and well-being.

Yale psychologist Laurie Santos recently turned her wildly popular course, "Psychology and the Good Life," into a free online class for high school teachers.

• Among her tips: A "little bit of extra sleep each night or exercise can make a world of a difference."