Sunscreen. Lightweight dresses. Bug spray. That one snack my youngest will actually eat on a plane. And two tablets (but without YouTube downloaded because my kids have meltdowns when I take it away).

I’m leaving for Costa Rica soon, but mid-packing, two things hit my inbox, and the timing felt almost poetic:

1. A landmark lawsuit against major social media platforms, like YouTube, with states arguing these companies knowingly engineered addictive products that harm children.
2. The 2026 World Happiness Report, with this year’s theme centered on social media. As I scrolled to find the U.S. (ranked 23, no surprise there), I noticed Costa Rica was #4. I also noticed this: they use just as much social media as we do.

The two emails don’t fit neatly together: one landed like relief, the other like a complication. Both can be true, and sitting with that might actually be a useful place to start. Boy, do I have questions, as both a mom and a scientist. A lot of parents do. But I wasn’t finding the level of detail and nuance I was looking for in high-level news articles.

So I went straight to one of the leading experts in this space. Dr. Jacqueline Nesi breaks down technology for kids on her Substack, and she was gracious enough to bring her expertise to the YLE community, too. Because, as she said, we’re all missing more from the headlines than we think.

Jacqueline, take it away…

What happened last week with the lawsuit?

For the first time, a social media company was held liable for harm caused by its product—not the content users posted, but the product’s design.

Platforms have long been shielded by Section 230, which protects them from liability for user-generated content. This case argued something different: that the features themselves caused harm. The companies will appeal, but if the verdict holds, the implications are enormous. Thousands of similar lawsuits are slated for trial this year, and mounting financial penalties could force real changes to how these products work.

Is this social media’s “Big Tobacco moment”?

Yes and no. The legal strategy rhymes: personal injury lawsuits uncovering evidence of deception, building toward larger class-action cases and eventual regulation.

But social media and cigarettes aren’t the same thing. Cigarettes cause clear, dose-dependent physical harm (i.e., there’s no safe way to smoke). Social media doesn’t work like that. The picture is far more complicated.

Does social media cause mental health problems?

The scientific community has substantial correlational evidence and some, but not much, causal evidence of harm. Studies that randomly assigned people to stop using social media show mixed results, depending on how long they stopped, whether they quit entirely or just reduced use, and what they were using it for. Natural experiments, like tracking mental health outcomes when Facebook arrived on different college campuses, do show increases in distress after introduction. But research still has a long way to go to get a clear answer.

For some kids, social media is clearly a contributing factor. A few years ago, I (Jacqueline) ran a study with adolescents experiencing suicidal thoughts in an inpatient hospital unit. Many of the patients I spoke to had complex histories of abuse, neglect, bullying, poverty, and other major stressors. Some of these patients used social media in totally benign, unremarkable ways. A few of them, though, were served with an endless feed of suicide-related posts and memes, some romanticizing or minimizing suicide. For those patients, it would be very hard to argue that social media did not contribute to their symptoms, even with everything else going on in their lives.

For the plaintiff in this case, is it possible that these social media platforms were one such factor? Yes.

But there’s a “but”?

Of course there is a but. Mental illness is idiosyncratic. Its causes differ between people, and for any one person, it is almost never the result of a single cause.

It is one thing to say that for some kids, social media is one factor contributing to mental health symptoms. It is another thing entirely to say that social media is causing mental health problems on a large scale. It is still the case that if you take an average, healthy teen and give them social media, this is highly unlikely to create a mental illness.

Are features like infinite scroll and auto-play addictive?

Many social media platforms are designed to keep people, including children, using them for long stretches. If a child is faced with infinite scroll (i.e., a feed that never ends), or auto-play (i.e., videos that automatically play, one after another), they are going to spend more time on a platform than they would if those features did not exist. These features are effective. A growing body of academic research suggests features like infinite scrolling, autoplay, and push notifications are engineered to make self-control difficult.

But, there is much debate in psychology about whether social media use (or, really, any non-substance-using behavior outside of gambling) can be called an “addiction.” There is no clear neurological or diagnostic criteria, like a blood test, to make this easy, so it’s up for debate:

• On one hand, some researchers argue that compulsive social media use shares enough features (loss of control, withdrawal-like symptoms, continued use despite harm) to warrant the diagnosis for treatment.
• Others say the evidence for true neurological dependency is still weak and inconsistent because research relies on self-reported data, findings haven’t been replicated, and many heavy users don’t show true clinical impairment without pre-existing issues.

Here’s my current take: There are a small number of people whose social media use is so extreme that it causes significant impairment in their lives, and they are unable to stop using it despite that impairment. And for those people, maybe addiction is the right word.

For the vast majority of people (and kids) using social media, though, I do not think addiction is the right word to use. Stepping back from that label allows us to:

1. Recognize the full picture: We can acknowledge the benefits teens report from social media, like staying connected with friends, meeting like-minded peers, and exploring their interests, instead of treating all use as inherently problematic.
2. Preserve agency: We can empower kids to develop healthy habits and self-regulation skills, rather than telling them they are powerless over their own behavior.
3. Drive systemic change: Preserving the precision of the addiction label—reserving it for the small number of kids whose use is genuinely compulsive and impairing—actually strengthens the case for platform accountability, rather than weakening it. It’s that targeted claim that has driven legal action and regulatory pressure. Expanding it to average use shifts focus from systemic design fixes to individual diagnosis, and dilutes the very argument that holds platforms responsible.

How does social media fit into the larger context?

Social media isn’t happening in a bubble; it is playing out within a larger societal landscape.

Take Costa Rica, for example. It doesn’t necessarily have fewer mental illnesses. And it certainly doesn’t have less social media use. What it has is a deep social fabric, and that may mean social media use reinforces real-world connections in Costa Rica, whereas in English-speaking countries, it may be replacing them.

In other words, cultural factors appear to be protective. The underlying challenges to social foundations—trust, connection, belonging, and safety—are what drive happiness. Friendships, being known by someone, the sense that you belong somewhere: these are the actual load-bearing pillars of mental health, more predictive of wellbeing than income, and more protective against mental illness than almost any intervention we have.

What does all of this mean for parents?

The risks of social media that we’ve long known about are the same, and so are the basics:

• If you know your teen is vulnerable, perhaps due to existing mental health challenges or social struggles, you may want to be extra careful.
• If your teen is using social media in moderation, and it does not seem to be affecting them negatively, it probably isn’t.
• For many families, it makes sense to delay introducing social media, and when you do, to go slow, with plenty of oversight.
• Have conversations, early and often, about the technologies in our pockets. Share the benefits and risks, and listen to your teen’s perspective, too.
• Consider limits to protect time for what matters, like social connection, sleep, and physical activity.

But when it comes to our kids’ mental health, it’s important to keep the whole picture in mind. Social media may be one piece of the puzzle, but it’s certainly not the whole thing.

Bottom line

This verdict is a crucial moment, legally and culturally. It’s a chance to return to what we already know: these products require caution, and we should be intentional about whether and how our kids use them.

But Costa Rica is a useful reminder that the goal was never zero social media. It was stronger foundations: real connection, real belonging, adults who show up. The verdict is a step toward making sure the products our kids use are built with that in mind.

It’s not enough on its own. But it’s a start, and so is the conversation.

Love, JN and YLE

POLL What aspects of social media’s impact on mental health do you want to know more about? Addiction Neuroscience & trends Regulations & policy History Other: Comment below!

Jacqueline Nesi, PhD, is a clinical psychologist, psychology professor at Brown, and mom of three. Subscribe to her newsletter Techno Sapiens for the latest research on living and parenting in the digital age.

A previous version of this was posted on Techno Sapiens here.

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” the ever-evolving public health science so that people will be well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below: