The Evidence

The Anxious Generation begins by examining adolescent mental health trends. What happened to young people in the early 2010s that triggered the surge of anxiety and depression?

By: Zach Rausch and Jonathan Haidt

March 2, 2024

The Evidence


Many mental health experts were initially skeptical that there was a mental health crisis raging among young people. The days after Jon published The Coddling of the American Mind, an essay appeared in The New York Times with the headline “The Big Myth About Teenage Anxiety.” In it, a psychiatrist raised several important objections to what he saw as a rising moral panic around teens and smartphones. He pointed out that most of the studies showing a rise in mental illness were based on “self-reports.” A change in self-reports does not necessarily mean that there is a change in underlying rates of mental illness. Perhaps young people just became more willing to self-diagnose or more willing to mistake mild symptoms of anxiety for a mental disorder.

Changing mental health norms and practices is certainly part of the story, and the psychiatrist was right to note that we need to look at multiple indicators of mental health problems to know if mental illness is really increasing. So, let’s dive into the data to see what is really happening. 

Below you will find the evidence laying out the there is a mental health crisis among our youth, that the crisis is international, and how the play-based and phone-based childhoods fit into this story. For a deeper dive into the evidence, check out our two major open-source Google Docs where we collect the citations and abstracts of the published articles that shed light on these topics (One on adolescent mental health trends and the second on the impact of social media on youth mental health). You can also read more on our Substack, After Babel, where we have published a series of articles on the international youth mental health crisis, the loss of the play-based childhood, and the rise of the phone-based childhood.

(Note that we do not address questions of causality on this page. You can learn more about that in the book or on the After Babel Substack. you can also find data on youth mental health trends around the world in our complementary open-source Google Docs). 

1. The Youth Mental Health Crisis

It starts in the early 2010s...

Figure 1. Percent of U.S. teens (ages 12-17) who had at least one major depressive episode in the past year (by self-report based on a symptom checklist). Data from U.S. National Survey on Drug Use and Health. This was Figure 7.1 in The Coddling of the American Mind, now updated with data beyond 2016. See the online supplement for these data split by race, region, and social class.

It is mostly “internalizing disorders,” like anxiety and depression...

Figure 2. Percent of U.S. Undergraduates Diagnosed with a Mental Illness. American College Health Association. [Zach’s spreadsheet].  See the online supplement for these data split be sex.

It hits younger people more than older people, Gen Z harder than any other generation...

Figure 3. Percent of U.S. adults reporting high levels of anxiety. Source: U.S. National Survey on Drug Use and Health, re-graphed from Goodwin, Weinberger, Kim, Wu, & Galea (2020) and updated with 2019-2021 data. [Zach’s Spreadsheet]. 

It’s not just self-report data. It’s also behavioral data like self-harm and suicide...

Figure 4. The rate per 100,000 in the population at which U.S. teens and pre-teens (ages 10-14) are treated in hospital emergency rooms for non-fatal self-injury. Data from U.S. Centers for Disease Control. [Zach’s spreadsheet]. See the data for 15-19 year-olds in the online supplement. 

It's not only that young people are going to the emergency department more. They are also being hospitalized more (which is reflective of more severe symptoms).

Figure 5. The rate per 100,000 in the population at which U.S. teens and pre-teens (ages 10-14) are hospitalized for non-fatal self-injury. Data from U.S. Centers for Disease Control. [Zach’s spreadsheet]. See the data for 15-19 year-olds in the online supplement. 

These trends are unique to adolescent girls.

Figure 6. The rate per 100,000 in the population at which U.S. females are treated in hospital emergency rooms for non-fatal self-injury. Data from U.S. Centers for Disease Control. [Zach’s spreadsheet]. 

The story for boys becomes clearer when we turn to suicide...

Figure 7. Suicide rates for younger U.S. teens (15-19), graphed from data from the U.S. Centers for Disease Control. [Zach’s spreadsheet]. See the data split by race and for 10-14 year-olds in the online supplement. 

Note that suicide rates today are higher for adolescent girls than any point previously recorded. In fact, suicide rates are higher for Gen Z girls in the United States, the UK, Canada, Australia, and New Zealand than any previous generation when they were young.

In other words, this is not just an American problem...

United Kingdom

Figure 8. Source: Cybulski et al. (2021), drawing from two databases of anonymized British medical records. Ages 13 - 16. [Zach’s spreadsheet]. See the data for other age groups and other measures of mental health in the online supplement. 


Figure 9. Emergency Department Visits of Ontarian boys and girls, 13-17, 2004-2017. Original graph from Gardner… & Lima (2019). Changing rates of self-harm and mental disorders by sex in youths presenting to Ontario emergency departments: Repeated cross-sectional study. Canadian Journal of Psychiatry. [Zach’s spreadsheet]. See more on Canadian adolescent mental health trends in The Coddling of the Canadian Mind? A Collaborative Review. 


Figure 10. Rate for 100,000 at which Australian teens were kept in hospitals overnight for mental health reasons. Source: Australia’s Health 2022 Data Insights [Zach’s spreadsheet]. See more on Australian adolescent mental health trends in The Coddling of the Australian Mind? A Collaborative Review. 

New Zealand

Figure 11. Total public hospital discharges for intentional self-harm by age and sex, 2005-2019. Ministry of Health, New Zealand. Data from The Ministry of Health’s National Minimum Dataset (NMDS). See 1.3.6 in The Coddling of the Kiwi Mind?


Figure 12. Percent of European students who experienced three or more psychological distress symptoms in the last week for at least six months. The percent change compares the average 2002-2010 scores with 2018 scores. Source: Health Behavior in School-Age Children Survey, 2002-2018. (See Zach’s spreadsheet for data points). See more on European trends in Zach's Substack post.


Figure 13. From Twenge, Haidt et al. (2021). Data from PISA. The Programme for International Student Assessment (PISA) survey of 15- and 16-year-old students around the world included a 6-item measure of school loneliness in 2000, 2003, 2012, 2015, and 2018 (n = 1,049,784, 51% female) across 37 countries. Note that the increase in school loneliness occurs in all regions other than Asia. [Zach’s spreadsheet]. See more on global adolescent mental health trends in Global Adolescent Mental Health Since 2010: A Collaborative Review.

The crisis goes beyond mental health...

Since the early 2010s, there have also been substantial declines in

What happened?

2. The Decline of the Play-Based Childhood

The story begins at the end of the 1970s as social trust collapses among adults. The "play-based" childhood starts to dissipate as parents become more fearful, overprotective, and less willing to let their kids spend time with other kids unsupervised in the real world.

Figure 2.1 Changes in UK children’s daily time use, based on Mullan (2019). Thanks to Nick Desbarats for making this figure.

The decline accelerates in the 1990s as parents start supervising their kids more...

Figure 2.2 Time spent parenting by U.S. mothers. (Source: Ramey & Ramey, 2000.)

And kids start spending less time with each other...

Figure 2.3 High school seniors get together with friends almost every day. (Source: Monitoring the Future)

Figure 2.4 Daily time spent with friends. (Source: American Time Use Survey, Special thanks to Dr. Viji Kanaan for these data.)

And do less of the stuff that they have historically done...

Figure 2.5 The percentage of U.S. high school seniors who have engaged in four adult activities (Source: Monitoring the Future).

As overprotection in the real world increased, a new and exciting virtual world opened up to kids. The old play-based childhood was being replaced...

3. The Rise of the Phone-Based Childhood

The virtual world arrives. Smartphones and social media platforms are adopted faster than any communication technology before it...

Figure 2.6 The share of U.S. households using specific technologies. The smartphone was adopted faster than any other communication technology in history. (Source: Our World in Data.)

The play-based childhood officially ends as teens' social lives move onto smartphones filled with social media apps...

Figure 2.7 The percent of U.S. adolescents who use social media platforms "nearly everyday." (Source: Monitoring the Future.). Thanks to Jean Twenge for sharing these data.

By 2015, one in five American teen girls use social media more than 40 hours a week...

By 2023, more than 46 percent of teens report being online "almost all of the time."

Childhood transformed into something unrecognizable. And it has caused an epidemic of mental illness among our youth.

For the full story, buy a copy of The Anxious Generation.

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