Social media is designed to be addictive, jurors found in a landmark trial against two of the biggest social media companies.
Research conducted in recent years increasingly suggests a causal link between Adolescent social media use and psychological harm. But this is the first time this link has been confirmed in court.
On March 25, jurors in a California civil trial found Meta and Google responsible for designing social media apps that could attract young users. The case involved a 20-year-old woman identified as Kaley, or KGM. KGM’s lawyers argued that she began using social media platforms, including Google-owned YouTube and Meta-owned Instagram, as early as elementary school, eventually spending up to 16 hours a day on Instagram alone. The lawsuit alleged that KGM’s self-esteem was tied to the number of likes and followers. This social media addiction has, in turn, led to many mental health issues, including depression, anxiety, body dysmorphia, and suicidal thoughts.
The legal battle focused on the design of social media platforms and not the content of posts. The plaintiff’s attorneys argued that tech companies knowingly designed their products to combat addiction by integrating features that keep people, especially vulnerable children and teens, coming back for more. These features include the ability to scroll endlessly or infinitely scroll, algorithms that provide curated content, short video clips, and push notifications.
The tech companies countered that scientists had not established a causal link between social media use and psychological damage and that KGM’s tumultuous childhood, not his social media use, was the cause of his mental health problems. YouTube’s lawyers also argued that the online video-sharing platform was not a social media company.
Both companies said they were exploring legal options, including appealing the decision. But this verdict should set a precedent for other similar ongoing cases.
We’re in the midst of a youth mental health crisis, says pediatrician Jason Nagata of the University of California, San Francisco. And the design of social media, while not the sole cause of poor adolescent health, is a problem that can be solved. “I think [the verdict] It’s a step in the right direction,” he said.
Scientific news spoke with Nagata to understand the societal implications of this verdict. His research with more than 8,000 children aged 11 and 12 found that preteens signs of social media addictionincluding thinking obsessively about social media and having difficulty switching off, experienced more mental health problems a year later than children without these signs. The results appear in the April 2026 issue American Journal of Preventive Medicine.
This interview has been edited for length and clarity.
SN: What makes the design features of these platforms so attractive to young users?
Nagata: We know that adolescents go through many changes in the brain, body, puberty. [and] growth. They constantly compare themselves to other teenagers. Social media exacerbates all of these comparisons in a really unrealistic way. Like some social media influencers, their content is heavily edited and filtered so that teens don’t compare themselves to other teens. They compare themselves to the highly filtered, edited, and curated versions of the best versions of other teens who may also be receiving ad money.
There is also evidence that even if adolescents are not, for example, searching for content related to their body image, they [still] get it through their feeds, perhaps based on age or powerful algorithms that continue to feed very similar content.
SN: Jurors had to decide whether the design features caused addiction. Why is this question of causality so difficult to answer?
Nagata: Our research, the Adolescent Brain Cognitive Development Study, also known as the ABCD Study, is one of the largest long-term studies of adolescent health in the United States. It contains a six-item questionnaire called the Social Media Addiction Questionnaire. Each of the questions reflects an element of addiction that might be observed in substance use. The questions therefore relate to conflict, relapse, tolerance or withdrawal.
In our study, we focused on young people aged 11 to 12. The minimum age to access these platforms is 13 years old. In our national study, two thirds of 11-12 year olds had underage accounts. We found that underage users who had higher symptoms of social media addiction suffered more from depression, ADHD. [attention-deficit/hyperactivity disorder]oppositional defiant and conduct problems a year later. They also slept less well.
Although the ABCD study is a very robust and large national study, we are unable to definitively prove causality. The gold standard method for proving causality is to design an intervention in which you have a control group and an intervention group. But I think designing such a study in this case would be unethical and impractical. We are therefore limited to observational data.
SN: Does this mean the jury overreached in finding the tech companies guilty?
Nagata: The jury was presented with evidence regarding specific individuals who may have been harmed by addictive features of social media platforms such as infinite scrolling, algorithms and constant notifications.
Our data reflects population-level trends.
I think this is one of those situations where we may never have the perfect randomized controlled trial to really get there. [issue of causality]. But two-thirds of 11- and 12-year-olds and more than 90 percent of adolescents [these platforms]. I think from a public health perspective it’s OK to start testing some of these policies and then rigorously evaluate them with science, but without waiting, without letting perfect be the enemy of good.
When can we start implementing some of these policies or interventions, even in the absence of perfect data?
SN: Meta and YouTube argued that KGM’s difficult childhood, not his use of social media, was the cause of his mental health problems. Can we separate education and addiction?
Nagata: Addiction likely has genetic, biological and environmental factors. You can’t really control your genetics. But I think social media and some of these environmental factors are changeable. And to the extent that we can address these modifiable factors, either by making algorithms less addictive or by reducing exposure to addictive elements… that may reduce the dependence of some users. With so many underage users and teenagers on [these platforms]these changes can have very widespread impacts on the population.
SN: What would help researchers identify the elements of social media that are so harmful to children?
Nagata: One thing that would be very useful for the research community would be to look at granular data from tech companies. Currently, the detail of data available to most scientists is quite limited. To better understand directionality and causality, it would be extremely helpful to have better access to real-time data, real-world content, and real-world interactions for individual users to better understand some of these potential causal relationships. For example, we might know if a user messages their friends with certain feelings or thoughts right after being exposed to certain content or certain types of platform design features.
If you or a loved one are at risk of suicide, the 988 Suicide and Crisis Lifeline offers free 24/7 support, information and local resources from trained counselors. Call or text 988 or chat on 988lifeline.org.