Published today in the peer-reviewed Journal of Human Development and Capabilities, the study found that 18- to 24-year-olds who had received their first smartphone at age 12 or younger were more likely to report suicidal thoughts, aggression, detachment from reality, poorer emotional regulation, and low self-worth.

The data also shows these effects of smartphone ownership at an early age are in large part associated with early social media access and higher risks of cyberbullying, disrupted sleep, and poor family relationships by adulthood.

A team of experts from Sapien Labs, which hosts the world’s largest database on mental wellbeing, the Global Mind Project – from where the data for this research was sourced – are calling for urgent action to protect the mind health of future generations.

“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,” lead author neuroscientist Dr Tara Thiagarajan, who is the founder and chief scientist of Sapien Labs, says.

“These correlations are mediated through several factors, including social media access, cyberbullying, disrupted sleep, and poor family relationships leading to symptoms in adulthood that are not the traditional mental health symptoms of depression and anxiety and can be missed by studies using standard screeners.” 

These symptoms of increased aggression, detachment from reality and suicidal thoughts can have significant societal consequences as their rates grow in younger generations, Thiagarajan says.

Smartphones have reshaped how young people connect, learn and form identities, however there are growing concerns about how AI-driven social media algorithms may amplify harmful content and encourage social comparison – while also impacting on sleep and more.

“Based on these findings, and with the age of first smartphones now well under age 13 across the world, we urge policymakers to adopt a precautionary approach, similar to regulations on alcohol and tobacco, by restricting smartphone access for under 13s, mandating digital literacy education and enforcing corporate accountability.”

Since the early 2000s, smartphones have reshaped how young people connect, learn and form identities.

But alongside these opportunities come growing concerns over how AI-driven social media algorithms may amplify harmful content and encourage social comparison – while also impacting on other activities such as face-to-face interaction and sleep.

Although many social media platforms set a minimum user age of 13, enforcement is inconsistent. Meanwhile, the average age of first smartphone ownership continues to fall, with many children spending hours a day on their devices.

Currently, it is a mixed picture internationally around the banning on phones in schools. 

In recent years, several countries have banned or restricted smartphone use in schools, including Australia, France, the Netherlands, Italy, and New Zealand.

Results of these moves are limited, however a study commissioned by the Dutch government has found improved focus among students.

In most Australian states, there are bans or restrictions on mobile phone use in public schools during school hours. 

The specific policies vary by state and school, but research indicates a mix of positive and negative outcomes, with some studies showing improved learning and social interaction, while others highlight potential drawbacks like reduced student autonomy and difficulty accessing digital learning tools. 

This month, policymakers in New York have announced it was to become the largest US state yet to ban smartphones in schools, joining locations such as Alabama, Arkansas, Nebraska, North Dakota, Oklahoma and West Virginia which have all passed legislation requiring schools to have policies that at least limit access to smartphones.

Across Australia, young people under 16 will be banned from using social media from December this year after the Federal Government passed the Online Safety Amendment (Social Media Minimum Age) Bill 2024 on November 28, 2024.

While the Bill’s objective is to protect children and young people from the harmful impacts of social media, it does not acknowledge that social media also provides young people benefits such as inclusion, social connection and belonging that are protective of mental health.

Australians under 16 will be banned from using social media from December by the Albanese Government, however mental health organisations say the ban doesn’t acknowledge that social media also provides young people benefits such as inclusion, social connection and belonging.

Amnesty International says a ban that isolates young people will not meet the Government’s objective of improving young people’s lives, and instead wants the Government to implement regulations for social media platforms that ensure the safety of children online and protect the right to privacy.

Overall, previous studies around the world into screen time, social media and smartphone access and various mental health outcomes have shown negative effects, but also mixed, often conflicting results – making it hard for policymakers, schools, and families to navigate this issue.

Possibly this may have to do with the use of screeners that miss the critical associated symptoms.

For this new analysis, the team at Sapien drew data from their Global Mind Project, and then used the Mind Health Quotient (MHQ) – a self-assessment tool that measures social, emotional, cognitive, and physical wellbeing – to generate an overall ‘mind health’ score.

Their results showed:

  • The specific symptoms most strongly linked with earlier smartphone ownership include suicidal thoughts, aggression, detachment from reality, and hallucinations.
  • Young adults who received their first smartphone before age 13 had lower MHQ scores, with scores progressively declining the younger the age of first ownership. For example, those who owned a smartphone at age 13 scored an average of 30, dropping to just 1 for those who had one at age five.
  • Correspondingly, the percentage considered distressed or struggling (with scores indicating they had five or more severe symptoms) rose by 9.5 per cent for females and 7 per cent for males. This pattern was consistent across all regions, cultures and languages, pointing to a critical window of heightened vulnerability.
  • That younger ownership is also associated with diminished self-image, self-worth and confidence, and emotional resilience among females, and lower stability and calmness, self-worth and empathy among males.

Further analysis indicated that early access to social media explains about 40 per cent of the association between earlier childhood smartphone ownership and later mind health, with poor family relationships (13 per cent), cyberbullying (10 per cent) and disrupted sleep (12 per cent) also playing significant downstream roles.

The researchers acknowledge the COVID pandemic may have magnified these patterns, but the consistency of these trends across all global regions suggests a broader developmental impact of early smartphone access.

While current evidence does not yet prove direct causation between early smartphone ownership and later mind health and wellbeing, a limitation of the paper, the authors argue that the scale of the potential harm is too great to ignore and justifies a precautionary response.

They recommend four key areas for policymakers to address:

  • A requirement of mandatory education on digital literacy and mental health.
  • To strengthen the active identification of social media age violations and ensure meaningful consequences for technology companies.
  • Restricting access to social media platforms.
  • Implementing graduated access restrictions for smartphones.

“Altogether, these policy recommendations aim to safeguard mind health during critical developmental windows,” Thiagarajan, whose research specialism focuses on the impact of environment on the brain and mind, says.

“Their implementation requires substantial political and societal will, effective enforcement, and a multi-stakeholder approach, but successful precedents do exist.

“For example, in the United States, underage alcohol access and consumption is regulated through a combination of parental, commercial, and corporate accountability.”

Thiagarajan says the evidence suggests childhood smartphone ownership, an early gateway into AI-powered digital environments, is profoundly diminishing mind health and wellbeing in adulthood with deep consequences for individual agency and societal flourishing.

“I was initially surprised by how strong the results are,” she shares.

“However, when you give it due consideration, it does begin to make sense that the younger developing mind is more compromised by the online environment given their vulnerability and lack of worldly experience.”

The academic says it is also important to point out that smartphones and social media are not the only assault to mental health and crisis facing younger adults.

“It explains some of the overall decline but not all of it,” Thiagarajan says. 

“Now, while more research is needed to unravel the causal mechanisms, waiting for irrefutable proof in the face of these population-level findings unfortunately risks missing the window for timely, preventative action.”