In a world where some toddlers scroll before they speak, a new global study is raising the alarm: the earlier a child owns a smartphone, the more likely they are to suffer from serious mental health issues by early adulthood.

The study examined more than 100,000 young adults across 40 countries. It found that those who received their first smartphone before age 13 were significantly more likely to report suicidal thoughts, aggression, and emotional instability by the time they reached 18 to 24 years old.

“Our data indicate that early smartphone ownership — and the social media access it often brings — is linked with a profound shift in mind health and wellbeing in early adulthood,” said lead author Dr. Tara Thiagarajan, neuroscientist and Chief Scientist at Sapien Labs.

The findings were drawn from Sapien Labs’ Global Mind Project — the world’s largest repository of mental wellbeing data — using a diagnostic tool called the Mind Health Quotient (MHQ). This self-assessment measures a broad range of mental and emotional functioning, going beyond traditional definitions of depression and anxiety.

Rethinking Childhood in a Digital Age

The data is sobering. Those who received a smartphone at age 13 scored, on average, 30 on the MHQ scale. That number drops to nearly zero for those who got their first device at age five. Scores on the MHQ range from −100 to +200:

• Scores above 100 indicate positive mental wellbeing and thriving.
• Scores below 0 indicate significant mental distress, with multiple severe symptoms that impair daily functioning.
• Scores between 0 and 100 reflect varying degrees of struggling or coping.

The younger the child is when they received their first phone, the more severe the symptoms in adulthood. Nearly half (48%) of females who had a smartphone by age five or six reported having suicidal thoughts, compared to just 28% who got theirs at age 13. Among males, the figure jumps from 20% to 31%.

Early smartphone owners were also more likely to experience hallucinations, detachment from reality, and heightened aggression. Girls also showed significant declines in emotional resilience and self-confidence. Boys showed reduced empathy and emotional stability.

These effects were consistent across languages, cultures, and regions. This was a massive study involving many thousands of young people.

“These symptoms… can have significant societal consequences as their rates grow in younger generations,” said Thiagarajan.

Virtual Life, Real Effects

In New Jersey, 12-year-old Mallory Grossman took her own life after months of cyberbullying through Snapchat and Instagram. Her parents later discovered a pattern of cruel messages and exclusion that played out on her phone — messages she kept hidden until the very end. “In the beginning, it was just teasing… exclusion was an important part,” her mother told CBS News. Mallory’s story sparked national headlines and renewed calls for stricter online protections for minors.

Thousands of miles away, in the U.K., 14-year-old Molly Russell’s suicide became a turning point. After her death, investigators found that she had viewed more than 2,000 pieces of content related to self-harm, suicide, and depression on Instagram and Pinterest. A British coroner later ruled that social media had contributed “in a more than minimal way” to her death. Molly’s case helped pave the way for the U.K.’s Online Safety Act, a sweeping piece of legislation aimed at holding tech platforms accountable for the psychological harm inflicted on minors.

In Australia, the nation’s eSafety Commissioner recently warned that 12- to 13-year-olds now account for 35% of all cyberbullying reports. A growing number of these cases involve threats encouraging self-harm or suicide. And many were driven by content circulated through unmoderated chat groups and comment sections.

Too Young to Scroll?

The analysis points to one key pathway: early access to social media.

According to the study, about 40% of the negative outcomes linked to early smartphone ownership were explained by early entry into social media platforms. Despite age minimums set by many platforms (typically 13) these rules are easily bypassed. Just input a random year close to your old man’s birthday and suddenly you have full access to the app.

Once inside, children encounter digital environments powered by AI algorithms designed to maximize engagement. This includes exposure to disturbing content, social comparison, and addictive behaviors — all during a period when the brain is still developing core emotional and social faculties.

Early social media access also raises the likelihood of being cyberbullied or becoming emotionally estranged from family. In English-speaking countries like the U.S., U.K., Canada, and Australia — referred to in the study as the “Core Anglosphere” — those downstream effects were particularly pronounced. In these countries, social media access explained up to 70% of the link between early smartphone ownership and poor mind health outcomes.

“When such exposure occurs at an age when sense of self, sexual maturity and worldly understanding are still forming, young users are particularly susceptible to their damaging effects,” the authors write.

The study found that disrupted sleep accounted for about 12% of the mental health issues observed in early smartphone users. Interestingly, this link was largely independent of social media use, suggesting that general smartphone activity — like late-night gaming or watching videos — may also interfere with brain development in young people.

Poor family relationships explained another 13% of the mental health impact, while cyberbullying accounted for 10%. These risks increase with younger access to social media, creating a web of interrelated harms that start early and echo into adulthood.

A Call for Action

This isn’t the first study to link digital technology with declining mental wellbeing in youth — far from it. But previous research has often produced mixed or conflicting results. That, researchers argue, is because many studies focus narrowly on symptoms like depression and anxiety, overlooking the broader picture.

Instead, the Global Mind Project used a more comprehensive approach, measuring 47 dimensions of emotional, cognitive, and social wellbeing. The findings support a growing view that today’s digital environments may be developmentally misaligned with childhood needs.

“Our evidence suggests childhood smartphone ownership… is profoundly diminishing mind health and wellbeing in adulthood,” Thiagarajan said.

So, what can be done?

The researchers stop short of calling for an outright ban but advocate for what they term a “developmentally appropriate, society-wide policy response.” Their recommendations include:

• Mandatory digital literacy and mental health education before children gain access to social media, comparable to how driver’s education precedes a license.
• Strict enforcement of age restrictions on social media platforms, with meaningful penalties for tech companies that fail to comply.
• Graduated access to smartphones, such as “kids’ phones” that offer basic communication without access to AI-powered platforms.
• Public policy modeled after tobacco and alcohol regulations, limiting use based on age-related vulnerabilities.

Importantly, they caution against placing the burden solely on parents.

“Parents who restrict smartphone or social media access for children whose peers are using them face the dilemma between protecting their children and risking their social exclusion,” the authors note.

They also argue that children shielded at home are still vulnerable to indirect effects like peer aggression or classroom disruptions, arising from broader smartphone use.

The researchers acknowledge that causation hasn’t been definitively proven. But they argue that the scale and consistency of the data justifies immediate, precautionary action.

“Waiting for irrefutable proof in the face of these population-level findings unfortunately risks missing the window for timely, preventative action,” said Thiagarajan.

As digital devices become ever more entwined with childhood, the question is not just whether smartphones are safe, but whether we are willing to accept the risks they bring when introduced too early.

The data suggest the answer should be no.

The findings appeared in the Journal of Human Development and Capabilities.