Should we wait until age 13 before giving our kids a smartphone?

I gave all three of my kids their first smartphone when they were 10 years old. The twins are 13 next month, and my youngest is 11 next month (Goodness me – July is expensive for birthdays!). Chances are, all three of them are currently sat somewhere with their phone in their hand or close-by. I wouldn’t say they are addicted, but I definitely worry a fair bit about their relationship with technology. Don’t all 21st century parents!?

Here in Bristol where I live, it’s entirely unremarkable that tweens have smartphones. The vast majority of my children’s friends got their first smartphone around the end of primary school, usually at 10 or 11, in the run-up to the move to secondary school. From the conversations I have had at the school gate and on the touchline, this is the UK norm. Anecdotally, the age is currently going down, with a growing number of year 5 and 6 kids (children aged 9-11) now in possession of their own phone. I personally think this lowering of the ‘age of onset’ has happened in the last 3-4 years, but that’s purely anecdote, not reliable evidence.

This UK ‘reality’ sits somewhat awkwardly alongside the loudest international voices on this question. The “Wait Until 8th” movement (a parent-led campaign in the US) urges families to delay until at least eighth grade (age 13 to 14). Jonathan Haidt’s “The Anxious Generation” (Haidt, 2024) turned the idea that smartphones have rewired childhood into a publishing phenomenon, even if it was based on less than compelling evidence.

Closer to home, the Smartphone Free Childhood campaign (Greenwell and Ryrie, founded 2024) has grown rapidly through UK parent WhatsApp groups, calling for delaying first smartphones until 14 and social media until 16. UK Government policy has moved in the same direction. The Department for Education’s updated guidance on mobile phones in schools (DfE, 2026) sets the expectation that all schools in England should be mobile phone-free environments by default, and from 29 June 2026 Section 36 of the Children’s Wellbeing and Schools Act 2026 gives this guidance the force of law. Australia has legislated a social media ban for under-16s. The UK Chief Medical Officers’ 2019 commentary on screen time and social media is overdue for revision, and a call for evidence on under-5s screen use opened in early 2026. Social media research is starting to explore really meaningful questions like the exciting ‘IRL Trial‘ led by Amy Orben and Dan Lewer in Bradford.

Into all of this drops two new pieces of evidence from Ran Barzilay’s team at the Children’s Hospital of Philadelphia, both drawing on the huge Adolescent Brain Cognitive Development (ABCD) study cohort. The first paper (Barzilay et al, 2026) looked at smartphone ownership and age of acquisition at age 12. The second paper (Bren et al, 2026), published today in JAMA Pediatrics, follows the kids who held out beyond age 12 to see what happens once they finally get a phone at 13. With a median age of first acquisition of 11 in the ABCD cohort, this is evidence that maps very closely onto the typical UK parenting trajectory, and I read both papers with more than the usual interest.

These recent papers by Barzilay and Bren suggest that the younger a child is when they get their first smartphone, the higher their risk of depression, obesity and insufficient sleep.

Methods

Both papers analyse data from the ABCD Study, a multisite US cohort following more than 10,000 children annually from age 9 or 10. Caregivers reported smartphone ownership (iPhone or Android), age of first acquisition, and (in the newer paper) total daily smartphone use, use by type, and whether the phone was placed outside the bedroom at night.

Depression was assessed using the validated K-SADS computerised diagnostic interview at age 12 and again at age 14. At age 13 the first paper used the self-reported Brief Problem Monitor (clinical threshold defined as a T-score ≥65), which captures broader psychopathology rather than depression specifically. Body mass index was objectively measured, with obesity defined as ≥95th centile. Sleep was youth-reported (insufficient sleep defined as <9 hours in the first paper and <8 hours in the second, in line with American Academy of Sleep Medicine recommendations).

Both studies used mixed-effects logistic regression with nested random effects for family and research site, adjusting for age, sex, race and ethnicity, household income, parental education, pubertal status, parental monitoring, and ownership of other devices (tablet, laptop, iPod, smartwatch). The authors controlled for pre-smartphone exposure for smartphone acquisition at age 12 and at age 13. The analyses that tested impact of acquisition at age 12 (paper 1) and age 13 (paper 2) additionally adjusted for pre-smartphone depression, obesity and sleep one year before acquisition. Paper 2’s analysis was pre-registered on OSF before the analysis was run.

Results

Paper 1 (Barzilay et al, 2026): smartphones at age 12

Of 10,588 children assessed at the 2-year follow-up (mean age 12), 6,739 (63.6%) already owned a smartphone. The median age of first acquisition was 11 years (range 4 to 13). The team ran three analyses: a cross-sectional look at ownership at age 12, a cross-sectional look at age of first acquisition, and a one-year prospective look at the subgroup who were smartphone-free at 12 and acquired a phone in the following year.

Table 1. Adjusted odds ratios from Barzilay et al, 2026 (Pediatrics)

Bold rows are statistically significant. All models adjusted for age, sex, race and ethnicity, income, parental education, pubertal status, parental monitoring, and ownership of other devices.

• In plain English: owning a smartphone at age 12 was associated with worse mental health, more obesity, and worse sleep.
• Each earlier year of acquisition was associated with a small increase in the odds of obesity and insufficient sleep, but not depression.
• Among kids who waited beyond 12 and then acquired a phone, both psychopathology and sleep problems rose over the following year, even after adjusting for their pre-phone levels.

Paper 2 (Bren et al, 2026): smartphones at age 13

The second paper zooms in on 1,959 youth from the same cohort who were still smartphone-free at the age 13 assessment, then follows them to age 14. Between the two waves, 1,230 acquired a smartphone and 729 did not. Outcomes were measured at age 14, with each model adjusting for the same outcome measured at age 13 (so the comparison is genuinely prospective).

Table 2. Adjusted odds ratios from Bren et al, 2026 (JAMA Pediatrics)

Bold rows are statistically significant. All models adjusted for pre-exposure measures of the same outcome, plus age, sex, race and ethnicity, income, parental education, pubertal status, parental monitoring, and ownership of other devices.

• The headline finding here is the contrast between acquisition and use. Simply getting a smartphone at 13 was not associated with depression or obesity at age 14, though it was associated with worse sleep.
• Among the kids who did get a phone, intensity of use was associated with all three outcomes, and the gap between heavy and light users was substantial:
  • kids using their phones for more than 5 hours a day had more than double the odds of depression and obesity, and double the odds of insufficient sleep, compared with kids using their phones for under 2 hours a day.
• The most clinically useful finding, though, is the simplest one. Kids who kept their phones outside the bedroom at night had a roughly one-third reduction in the odds of insufficient sleep, from a single behavioural change.

This research suggests that later acquisition of smartphones is consistently safer, but do these potential harms outweigh the benefits?

Conclusions

Taken together, these two well-conducted research studies point in a consistent direction. The younger a child is when they get their first smartphone, the higher their risk of depression, obesity and insufficient sleep over the following year.

Barzilay et al (2026) found that owning a smartphone at 12 was associated with all three outcomes, that each earlier year of first acquisition was associated with higher odds of obesity and insufficient sleep, and that acquisition of smartphone at age 12 was associated with greater psychopathology and worse sleep the following year, even when adjusting for pre-smartphone mental health and sleep. Bren et al (2026) found that delaying acquisition until 13 removed the association with depression and obesity at age 14, although the association with insufficient sleep remained. The authors of the newer paper conclude:

Results suggest that simply acquiring a smartphone at age 13 is not associated with depression or with obesity, but is associated with insufficient sleep, at age 14. However, the amount of smartphone use is associated with higher odds of all three outcomes. Behavioral interventions like limiting smartphone-time and keeping smartphones out of bedrooms at night may protect adolescents from potential adverse health outcomes.

For parents reading this, the headline is simple. The older a child is when they get a smartphone, the better their odds. No age is risk-free, but the case for waiting is getting stronger.

Strengths and limitations

There is a lot to like in both papers. The ABCD Study is one of the best adolescent cohorts in the world, with a large, multisite, demographically diverse US sample, objectively measured BMI, and validated K-SADS interviews for depression. Both papers include genuinely prospective analyses that adjust for pre-exposure depression, obesity and sleep, so the comparison groups share a common starting point.

This is the strongest design either team could run with observational data, and it is the basis for the most causally interpretable findings in each paper. Paper 2 went further by pre-registering its hypotheses and analysis plan on OSF before the data were inspected. Both papers included E-value sensitivity analyses to test how strong an unmeasured confounder would need to be to explain away the findings, used mixed-effects models that account for family and site clustering, and shared their analytical code openly on GitHub. The team are also commendably honest about what they could not do.

There are several limitations worth flagging:

• Smartphone ownership, age of first acquisition, and daily time of use were all measured by single self-report or parent report questions. We know from prior ABCD work using passive sensing that self-reported smartphone time is only modestly correlated with objectively logged use. The entire “intensity” story therefore rests on a measurement instrument with known accuracy problems.
• The pre-registered social media hypothesis (that social media use specifically would drive the adverse outcomes) could not be formally tested, because data on use-type were missing for too many participants (35.5% of participants had no data on social media use, 58.5% had no data on video chatting, and 32.3% had no data on video gaming). This is the question most parents, clinicians and policymakers care about, and the paper cannot answer it.
• The prospective analyses in both papers, which are the strongest pieces of evidence either team reports, were necessarily restricted to kids who were still smartphone-free at the prior assessment (age 12 in Paper 1, age 13 in Paper 2). Those subgroups skewed towards higher socioeconomic status, because the children who managed to delay first acquisition came disproportionately from higher-income, more-educated families. The authors argue this likely underestimates the true population effect size, citing European evidence that adverse effects may be larger in lower-SES youth, but that is plausible rather than demonstrated.
• Both papers come from a single cohort with no replication. The depression finding for acquisition at 13 (OR 1.45, 95% CI 0.98 to 2.14) is right on the boundary and could move in either direction with more power. There is also some construct slippage in the first paper, where the age-13 outcome is broad psychopathology rather than depression specifically.
• Finally, the disclosures. Dr Barzilay holds stock in Taliaz Health and serves on the Scientific Advisory Board of Children and Screens (an advocacy organisation with a clear position on this issue). Dr Visoki’s spouse has interests in Kidas. The authors state these are not relevant to the work. Readers can decide for themselves.

The social media question that the public most wants answered, these studies could not formally test.

Implications for practice

For the majority of UK parents, the question is not whether to give a child a smartphone before 13. By the time most kids are starting secondary school in this country, the decision has effectively already been made for us by peer norms, school communication channels, the school run, and the perfectly reasonable wish for our children to be able to contact us. The conversation has to start from that reality.

Different readers will want different things from this evidence, so the recommendations below are split by audience. They are drawn from across both papers.

For young people

The evidence in these papers is about you, but it is rarely directed at you. Here is what it actually says:

• Get your phone out of your bedroom at night. Kids in this study who did, had roughly one-third lower odds of being short on sleep. This is the single most useful thing you can do.
• Watch the heaviest end of use. Self-reported use of more than 5 hours a day was linked to roughly double the odds of depression, obesity and insufficient sleep, compared with less than 2 hours a day.
• You can be the one who decides to put it down, before someone else decides for you.
• If your parents (or your school) put limits on your phone, this is not a punishment. The evidence in these papers is real science about real bodies and real minds, including yours. Time limits and the bedroom rule are about protecting how you sleep, how you feel and how you grow, not about controlling you.

For parents and caregivers

If your child already has a smartphone (which is the majority of UK households by the start of secondary school), the levers that matter most are time and bedroom access. If your child does not yet have one, you still have the option to wait.

• Take phones out of bedrooms at night. A basket on the kitchen counter, or a charging point in the hallway, works. This is the strongest behavioural finding in either paper. Keeping phones in bedrooms overnight is linked with insufficient sleep.
• Model the behaviour yourself. Your kids notice your phone habits more than they notice your rules.
• Set an agreed daily time limit and be consistent. Use built-in iOS or Android controls if it helps. The risk gradient gets steep above 2 hours a day and steeper still above 5.
• If you can still wait, wait. The evidence supports delaying first-smartphone acquisition. There is nothing magic about the number 13, but later is generally safer than earlier.
• Use the AAP PhoneReady Questionnaire to structure a readiness conversation, focusing on judgement, impulsiveness and accountability rather than peer pressure.
• Have a real conversation with your child about the findings. These two papers show smartphone use directly affecting sleep, weight and mood, so decisions about when to acquire a phone and how much to use it are decisions about health. Kids are far more likely to accept a rule when they understand the science behind it.

For clinicians

Smartphones now need their own clinical conversation, separate from the older “screen time” construct.

• Add smartphone use to routine adolescent wellbeing assessments. “Do you sleep with your phone in your bedroom?” and “How many hours a day are you on it?” are useful starting questions in GP, paediatric and school nurse consultations. Also ask what they do on their phones.
• Flag the >5 hours a day threshold as a concrete warning sign for mental health, weight and sleep risk.
• Where sleep is the presenting concern, the bedroom-phone rule has the most direct evidence behind it. It is worth a specific recommendation, not a general one.
• Do not conflate smartphone use with social media use. This evidence cannot speak to the social media question; treat them as separate clinical conversations.

For policymakers

The timing of this evidence is striking. The new statutory mobile-phone-free schools regime under the Children’s Wellbeing and Schools Act 2026 comes into force on 29 June 2026, just three weeks after Bren et al was published. The government’s ongoing work on restricting under-16s’ social media access continues.

• Sit behavioural guidance alongside age-based legislation, not after it. Daily time limits and bedroom-free rules are the levers parents can actually use, regardless of acquisition age.
• Update the 2019 UK CMOs’ screen time commentary. It pre-dates almost all of the smartphone-specific evidence, and these papers are reasons to revisit it.
• Invest in objective measurement. Self-report has taken this field as far as it can go. The next wave of research needs passive sensing and bigger, more socioeconomically diverse samples.
• Treat the social media question as open. The pre-registered hypothesis in Bren et al could not be tested. Future legislation should be grounded in evidence that does not yet exist.

Have a conversation with your kids about this new research. What impact does it have on your decisions about technology?

Personal reflection

As for me, I am not going to pretend that the smartphone-at-10 decision is going to be unwound, and pretending otherwise would not be honest to where most UK families actually are. My kids have experienced many benefits from using smartphones so far, including communicating with friends and family, learning languages, creating art and music, and generally having fun.

Are these positive experiences worth the risk and potential harm in terms of impact on their health? That’s a question that each of us as parents has to answer for our own children, and indeed for ourselves. I’m certainly going to be talking with my kids about this new research and deciding as a family what impact it has on us.

They may all be messaging Ran Barzilay in Philadelphia and encouraging him to do less research on smartphones and children in future!

All the family phones charging downstairs at bedtime might be the single most evidence-based intervention I can implement tonight.

Statement of interests

I am a parent of three children, aged 10, 12 and 12, all of whom received their first smartphone at age 10, around the typical UK transition from primary to secondary school. This lived experience as a parent of smartphone-owning children will inevitably shape how I read this evidence, and I have flagged it so readers can take that into account.

I have no professional or financial relationships with any commercial party with a stake in adolescent smartphone use. I know one of the authors of these research papers, but I had no involvement in the research.

I am a Trustee at the Centre for Mental Health and an Honorary Research Fellow at the University of Bristol. I am also the Co-Founder and Co-Director of The Mental Elf and it’s sister company Minervation Ltd. I have lived experience of depression and anxiety which is well documented elsewhere on this site.

I used AI (Claude) to edit and improve this blog, but the ideas in it and the appraisal of both research papers was done by me.

Links

Primary papers

Bren Z, Tran KT, Visoki E, Waasdorp TE, Moore TM, Pimentel SD, Barzilay R. (2026) Smartphone Acquisition and Use at Age 13 and Their Associations with Health Outcomes at Age 14. JAMA Pediatrics. Published online June 8, 2026. doi: 10.1001/jamapediatrics.2026.2118

Barzilay R, Pimentel SD, Tran KT, Visoki E, Pagliaccio D, Auerbach RP. (2026) Smartphone Ownership, Age of Smartphone Acquisition, and Health Outcomes in Early Adolescence. Pediatrics 157(1):e2025072941. https://doi.org/10.1542/peds.2025-072941

Other references

Department for Education (2026) Mobile phones in schools (updated 19 January 2026). London: DfE.

Children’s Wellbeing and Schools Act 2026, Section 36. UK Parliament.

Smartphone Free Childhood. UK parent-led campaign (Greenwell D, Ryrie J). https://smartphonefreechildhood.co.uk

UK Chief Medical Officers (2019) Commentary on screen-based activities and children and young people’s mental health and psychosocial wellbeing. Department of Health and Social Care.

Haidt J. (2024) The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness. Penguin.

Paruthi S, Brooks LJ, D’Ambrosio C, et al. (2016) Consensus Statement of the American Academy of Sleep Medicine on the Recommended Amount of Sleep for Healthy Children. Journal of Clinical Sleep Medicine 12(11):1549-1561. 10.5664/jcsm.6288

Wait Until 8th. https://www.waituntil8th.org/

American Academy of Pediatrics PhoneReady Questionnaire.