
“How did your teen do during the pandemic?” That’s a question I often ask other parents, and their answer is almost always the same: Their sons were fine – they even flourished during Zoom school, getting more sleep and spending more time playing video games. Their daughters imploded.
After decades of improvement, the share of children, teens and young adults reporting depression, anxiety, suicidal ideation and eating disorders has risen alarmingly. For example, the share of teens reporting persistent feelings of sadness increased by 40% from 2009 to 2019 and now affects more than one in three. Teens are contemplating suicide and harming themselves at higher rates.
What has not received much coverage is how much worse the mental health crisis is playing out for girls. Splitting statistics by gender shows that in 2019 almost half of teen girls reported persistent feelings of sadness, compared to a quarter of the boys. The share of adolescents with suicidal thoughts or self-inflicted injuries has also grown faster among girls.
The gender gap widens
Then, during the pandemic, the gender gap of teen mental health crisis exploded. According to the CDC, weekly visits by kids to the emergency department (ED) for psychiatric conditions plummeted when the COVID-19 emergency was declared in March 2020. But over the following months the number of girls in crisis coming to the ED rebounded to pre-pandemic levels, while it remained low for boys.
The gender gap is even starker for certain psychiatric conditions. Eating disorders, which can be fatal, happen when a child tries to control their weight with severe food restriction (anorexia) or purging (bulimia). During the pandemic, the number of girls requiring hospitalization for eating disorders more than doubled, while boys’ rates were unaffected.
Another curious gender disparity occurs with tic disorders. Tourette’s syndrome, a neurological disorder that causes involuntary physical movements or vocalizations (tics), typically affects more boys than girls. During the pandemic, however, the number of girls with Tourette-like symptoms skyrocketed. The similarity of vocalizations and movements seen in teen girls from all around the world led doctors to suspect that they “caught” the tics from social media influencers. Apparently, for these girls the emotional stress of the pandemic was expressed as a physical disorder.

Behind the teen mental health crisis
Experts don’t agree on the reasons for the decline in teen mental health. A few narratives have emerged about what drives the crisis, with the prime suspects being technology (especially social media), the social climate, and modern parenting.
Blame the parents hypothesis: The main proponent for this hypothesis is Jonathan Haidt, a social psychologist at New York University, who in a 2018 book The Coddling of the American Mind blamed modern parenting strategies for the decline in adolescent mental health. The thinking goes as follows: anxious parents raise anxious kids. There is little empirical basis for this hypothesis, however. First, we had not seen a substantial rise in adult anxiety, at least not enough to create an epidemic of “anxious parenting.” Second, psychologists dispute how much influence parents have on how their kids turn out in the first place (as long as they do not abuse or traumatize them).
The world on fire hypothesis: Without a doubt, life is stressful for teens these days. Colleges are much more difficult to get into than for earlier generations, and also much more expensive. The relentless negativity of the news cycle offers no respite, and the climate change disaster leaves little room for hope. While these are valid points, as a GenX-er, I remember how dire things were in the 80s and 90s, how scary it was to live under the threat of nuclear annihilation and how precarious life seemed during the AIDS epidemic.
The technology hypothesis: Technology – specifically, smartphones and social media – is the likeliest explanation for the decline of teen mental health. One of the major proponents of this hypothesis is Jean Twenge, a psychologist at San Diego State University, who in her 2017 book iGen observed that the uptick in mental health issues coincides with the first generation to go through puberty with a smartphone. There is no debate that teens spend much of their time tethered to a screen — whether playing games, watching videos or being on social media. Technology is harmful not just for what it enables – social media has been blamed for bullying, harassment and negative body image – but also for what it replaces, namely sleep and in-person interactions. A sleep-deprived brain is vulnerable to stress, and in-person interactions help teens regulate stress and emotions and reclaim the value of human empathy, connection and belonging.
As a researcher who studies social media, I share the growing sense of unease about its adverse effects on society.
The above explanations are plausible, but they don’t explain the gender gap. At best, the differences between boys and girls are small. According to Common Sense Media, girls spend only about 15% more time on social media than boys. (On the other hand, boys spent twice as much time playing video games, almost two hours longer each day.) College admissions process is likely more stressful for girls now, since they are the majority of applicants, but by a small margin. Nor is there evidence that boys and girls are parented differently.
As a researcher who studies social media, I share the growing sense of unease about its adverse effects on society. However, I do not think social media alone is to blame for the mental health crisis. Rather, I suspect that technology – by which I mean the algorithms that power the web and social media – creates a hostile environment for girls. I believe these algorithms amplify small differences in the behaviors of boys and girls to create a large gender gap in emotional wellbeing, in the following ways:
Psychological contagion: Social media may contribute to the mental health crisis indirectly, by promoting interactions that erode wellbeing. One way this can happen is through psychological contagion in which emotions spread from person to person. This can be especially potent when combined with a psychogenic illness – when mental stressors create physical symptoms of a disease.
How does it work? Social media facilitates the contagion of mental stressors by connecting people and then compounds the problem by giving peers an opportunity to signal their approval or disapproval. The feedback loop between psychological contagion and social approval can promote both positive and negative behaviors.
Take support groups, which are examples of virtuous cycles where individuals model positive behaviors and receive approval for them. But the same mechanisms can also amplify negative behaviors. For example, “pro-ana” and “pro-mia” groups end up promoting anorexia (ana) and bulimia (mia) by sharing tips on how to tolerate extreme hunger and cheering members who severely restrict food.
Although few cases of psychological contagion through social media have been documented, many examples of media contagion exist. For example, before western TV programming was introduced on Fiji in the mid-1990s, purging as a way to control weight was unknown. After TV, purging in girls rose to 45% by 2007, according to one study. Due to the risk of copycat suicides, responsible journalists now follow guidelines on reporting about suicides.
Social exclusion: When girls go online, they find a world inhabited largely by men. Inevitably, they confront misogyny: Two-thirds of adolescents users report they sometimes or often encounter sexism and body shaming on social media. Online harassment stresses girls by making them feel excluded.
The world girls find online is designed largely by men – in the algorithms that organize their social feeds, answer their search queries and offer them personalized recommendations. Consider the disparate impacts of algorithms on the online experiences of boys and girls.
Boys, who spend much of their free time playing games, compete against opponents selected by algorithms to have similar skill levels. These algorithms adjust aspects of the game to ensure that players have a fun, fair experience, with a range of engaging options for every player.
Girls, who prefer to use social media, have an entirely different experience. Algorithms that curate their social media feeds present them with a stream of viral content from influencers featuring unattainable ideals of beauty and power. Inevitably, such content invites negative social comparisons that impact mental health. Additionally, the structure of online connections of social networks like Instagram enables influencers and “popular” friends to distort perceptions of what is acceptable or desirable and fuel FOMO – the fear of missing out.
Self-radicalization: Algorithms that power search engines and recommender systems create other disadvantages for girls. According to Common Cause Media, girls use the web to search for health and wellness information more than boys. Algorithms lead them down rabbit holes to sites offering cures to the problems of a culture’s own making. Imagine a girl who is unhappy about her weight and looks for dieting tips online. It does not take long for search algorithms to lead her to extreme content that promotes anorexia and extreme weight loss. Although some platforms try to keep kids away from harmful content, others offer few, if any, safeguards.
Looking to the future
As algorithms blur divisions between the online world and the physical world, the internet and social media are having an increasingly toxic effect on girls, making them feel stressed, anxious and depressed.
What will happen in the future when an ever-growing portion of important social interactions take place in the metaverse, or some hybrid online-offline world, where interactions look and feel real but there is no accountability for them? How will it disadvantage girls, women and other underrepresented groups?
We need to rigorously study the way these algorithms are constructed – and the social values that are embedded within them – in order to understand and anticipate their effects on society. We need to hold social media platforms accountable so that they mitigate the harms their technologies create. Finally, we need to educate children to be responsible digital citizens who are aware of how algorithms work and mindful of the pernicious feedback loops they can create.
Kristina Lerman is principal scientist at USC Information Science Institute and a research professor of computer science at USC.