Avoid Giving Smartphones to Children Under 13, Research Suggests

The second is a new research review on the threat to youth mental health damage posed by chemicals in our food and drink. You’ll also find out why Sapien Labs is especially focused on these two particular issues.

Early smart phone use linked to poorer mental health in young adults

My husband and I were trying to remember exactly when our son first got a smart phone, and we pinpointed it to about age 15, when he successfully lobbied us to let him walk and bike home from junior high. Our younger daughter made the same case for one at age 14, arguing impassionedly that it would let us track her location “in case I’m kidnapped.” Overjoyed to have cell phones, the kids were swept up in endless hours of texting and online games, although we did manage (barely) to keep the phones turned off for family meals and bedtime.

We’d been hesitant – when my daughter first asked for one, during elementary school, we were put off by the after-school sight of several kids on the playground not talking, not playing, but hunched over their devices. We’re relieved to have waited for a number of reasons, including a newly published global study by Sapien Labs that links pre-teen smartphone ownership to poorer mental health and well-being in young adulthood.  

This remarkable study, based on data from its Global Mind Project involving more than 100,000 young people, found that 18-to-24-year-olds who were given 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 findings, published yesterday in the peer-reviewed Journal of Human Development and Capabilities, noted these problems were largely associated with smartphones through early access to social media – as well as higher risks of cyberbullying, fragmented sleep, and “poor family relationships” by adulthood.

This follows a Sapien Labs report we reported on in January of this year, which found global worsening mental health problems at younger ages, especially among 13-to-17-year-olds – also with a link to early cell phone use. (That research formed the basis for this new report.) At the time, our colleague Don Sapatkin reported that the analysis found that 42% of adolescent girls in the U.S. cited suicidal thoughts and intentions among their worst problems, compared to 27% of boys. More than 45% of teens cited a sense of being detached from reality as one of their worst problems. Among those who said they’d gotten their first smartphone by age 9, almost 40% said aggression toward others was among their worst problems. That figure was 30% for those who reported getting their first smartphone after 13.

In the new study, as before, researchers used a measure of overall youth mental health called a Mind Health Quotient (MHQ) score – a score of +200 indicates a thriving state of mental health, with one of -100 indicating severe distress. The Arlington, Virginia-based lab found that MHQ scores were lower in young adults who received their first smartphone before age 13 with scores progressively declining the younger the age of first ownership. For example, those who first owned a smartphone at age 13 scored an average of 30, but that score dropped to just 1 for those who had got one at age five.

The study, the latest to link smartphone use to a decline in young adult mental health, also found a correlation between young smartphone ownership and diminished “self-image, self-worth and confidence, and emotional resilience among females, and [lower] stability and calmness, self-image, self-worth and empathy among males.” In addition, the percentage of such young adults showing 5 or more symptoms of severe distress or struggle rose by 9.5% for females and 7% for males. Specific symptoms correlated with early use included “suicidal thoughts, aggression, feelings of being detached from reality, and hallucinations.” Of females who acquired their first smartphone at age five or six, 48% reported severe suicidal thoughts, compared to 28% for those who got their first at 13. (For males, the equivalent figures were 31% and 20%, respectively.)

Given the weight of these peer-reviewed findings, the researchers recommended four urgent policy solutions: 1) mandatory education on digital literacy and mental health; 2) active, enforced age restrictions on social media platforms with “meaningful penalties for non-compliance”; 3) technical measures on devices preventing all social media on under-13’s devices; and 4) graduated access restrictions on smartphones.

In a press statement, lead author neuroscientist Dr. Tara Thiagarajan noted that the authors’ policy recommendations “aim to safeguard mind health during critical developmental windows.” She said that their “evidence suggests childhood smartphone ownership, an early gateway into AI-powered digital environments, is profoundly diminishing mind health and wellbeing in adulthood.”

Thiagarajan also noted that other factors, including the pandemic, doubtless contributed to the decline in mental health among young adults and need to be investigated.“I was initially surprised by how strong the results are,” she added. However, given children’s vulnerability and lack of experience, she states, “it does begin to make sense that the younger developing mind is more compromised by the online environment.”

But these important population-level findings, she suggested, mean that waiting for incontrovertible proof “risks missing the window” to prevent further damage.

A short Q&A on smartphones, cyberbullying and kids with lead author Dr. Tara Thiagarajan

We reached out via email to Thiagarajan, who is the founder and chief scientist of Sapien Labs, with some questions. 

MindSite News: Do you think parents who have recently given smartphones to their children in elementary school should try to “wean” the children from their phones, in light of the findings from your research? 

Dr. Tara Thiagarajun: This is a tough challenge, especially when your child’s friends have a phone. I’m not a parenting expert (and our paper is more about policy), but I think talking to your children and modeling phone-free behavior is important. It is hard to wean your child if you are not able to get off your phone yourself.

MindSite News: Are there other protective steps you’d suggest parents might want to try to counter the damage from smartphone use in their children?

Our data shows that the younger kids get a phone, the more likely they are to end up experiencing some form of cyberbullying by the time they enter adulthood – and we have shown in a different report that cyberbullying has severe and long lasting mental health effects. 

We have all for the most part simply handed our children phones without any instruction on how to use social media in a healthy way, how to understand what is bullying and what is not, how to identify phishing, and in most cases without any controls over what kind of sites they visit such as porn or violence. It is important for parents to talk about this with their kids and keep tabs on what they are doing. You wouldn’t let your kid go to unsafe places in real life. You shouldn’t let them go to unsafe places virtually, either.

Our data also shows that having a smartphone early is also likely to exert its effects through impacting sleep and family relationships. The former could be because of scrolling at night and getting insufficient sleep during critical developmental periods when sleep is extremely important, so taking away the phone at bedtime could be a strategy. The latter could be because the more the child is on their phone at a young age, the less time spent engaged with the family and forming close family bonds that are important. Parents should prioritize in person, phone free-time with their children. 

MindSite News: What steps do you think social media companies should be required to take to keep young children from accessing social media sites, given how easy it is to create fake identities online?

In most places 13 is already the minimum age but it is easily circumvented. It should require either identity and DOB verification (e.g. learners permit/drivers license) or birth certificate and parental consent before the age of 16. Consider that any kind of social science study in academia requires such consent to show content or ask the most benign things – with IRB (institutional review board) panels worrying about triggering and exposure to inappropriate things – but a child can simply get on the Internet and view any kind of sexual or violent content or post responses to all sorts of strange things with no checks.”

Neurotoxins in food may also hurt youth mental health: Sapien Labs

Dr. Thiagarajan (above) also recently led a narrative review of research into the potential impact of toxins in our food and drink on mental health and the brain.

She and her co-authors found that many substances commonly found in processed and supermarket foods are not only unhealthy, but are actually neurotoxins (substances that harm the nervous system), or disruptors of gut and hormonal systems that may be contributing to the global decline in youth mental health. They shared their findings in an advance copy of a peer-reviewed report that will appear in Neuroscience & Biobehavioral Reviews’ September 2025 issue.

Pesticides, heavy metals in groundwater and soil, and microplastics in food harm brain development and mental function, Thiagarajan and the other experts explain. Younger generations also have more exposure to toxins earlier in development now than in earlier generations, researchers say. Despite this, neuroscience journals have paid scant attention to the impact of food toxins on the brain.

One factor affecting youth mental health “often overlooked, is the increasing exposure of children and adolescents to neurotoxic and neuro-disruptive chemicals in the food and beverages they consume,” the authors write, highlighting chemicals like pesticide residues, heavy metals, additives, and microplastics and bisphenols that are found in soil, groundwater, food or its packaging. In one alarming example, they write that “plastic baby food containers can release up to 4 million microplastic and 2 billion nanoplastic particles from only one square centimeter of plastic area within 3 minutes of microwave heating.”  

The concern is that these chemicals have since been found throughout the body. They cite a number of studies and biomonitoring programs that have found those chemicals in bodily fluids including umbilical cord serum, breast milk, cerebrospinal fluid and the brain, “indicating they can traverse around the body and cross the blood-brain barrier.”  At the same time, studies investigating the impact of pesticides, heavy metals and plastic in children and teens have been found to “harm brain development and mental function.”

Their article reviews calls associations between neurotoxins and “disruptors” and adverse youth mental health outcomes “a grave threat to the future wellbeing of society.” Overcoming this critical gap in research, they say, “is essential for safeguarding the brain health and mental wellbeing of future generations before the consequences become irreversible.”

We asked Thiagarajan about the research review and what steps could be taken to reduce risks:

MindSite News: This research should raise deep concerns among both scientists and parents. Given the paucity of research in this area, what recommendations do you have for parents and neuroscientists?

Dr. Tara Thiagarajan: This is very tough since toxins are ubiquitous but some things we can do include:

1) Avoid ultra-processed food as much as possible in favor of fresh food. Look at food labels for things you don’t recognize as normal kitchen ingredients and be aware that the term ‘Natural Flavors’ is a catch all for all sorts of chemicals derived from plants and animals and doesn’t mean they are non-toxic.

2) Eat organic as much as possible, or if that is not possible, wash produce thoroughly under running water.

3) Get a water filter. 

4) Use metal or glass water bottles, cups, plates and kitchen utensils — avoid plastic and coated pans.

5) Avoid eating and drinking hot food from plastic or plastic coated containers. Given that this is hard to avoid if you eat out or get coffee to go, it could help to carry your own coffee mug and metal take-out containers.

Our most important recommendation to neuroscientists is to pay attention to this issue as part of their research. There is a great deal that we still need to understand in terms of the long-term effects of commonly used food chemicals on the brain and mental health symptoms.  With thousands of chemicals now in our food and water, a great deal of research is required to learn how they affect brain physiology from neuronal signaling to the structural integrity of brain cells and the blood brain barrier and to understand which ones have more deleterious effects than others.

MindSite News: Given your research on risk factors, what more can parents do in regard to the youth mental health crisis?

It is important to be aware of the risks to mental health and consciously create a home environment for your child that is brain/mind healthy so they don’t end up with mental health problems.  This includes the food and water they consume and the content they consume as well as ensuring that there is a lot of in person/device free social engagement and exercise in their lives.

MindSite News: With the many factors contributing to the youth mental health crisis – including stress from climate change, social isolation intensified by the pandemic, and increasing income inequality that creates downward mobility for many young people and threatens their future, how did you come to focus on social media and neurotoxins and endocrine disruptors in foods? 

We have studied a wide range of social and environmental factors to determine which ones are more impactful and actionable through individual behaviors and policy. Surprisingly, ultra-processed food consumption comes out as one of the strongest factors after controlling for others, followed by having a smartphone at a young age, with each having different effects.