Among the side effects of excessive screen time reported by complainants are depression, anxiety, eating disorders, self-harm, and suicidal tendencies among thousands of children and young people.

Last year, the United States Congress questioned the CEOs of the most prominent related companies, such as Shou Zi Chew, owner of TikTok, or the director of Meta, Mark Zuckerberg, who stated: “I am sorry for everything they have gone through, …no one should have to go through the things their family members have suffered.”

But are there any valid reasons for concern?

An interesting  meta-analysis  has just been published that brings together twelve studies including a total of 11,234 participants, in which the evidence obtained by neuroimaging techniques, related to the effects of digital media on adolescent brain development, is systematically reviewed and synthesized, analyzing reward circuits and cognitive control during critical periods of development.

The study, which includes adolescents aged 11 to 19, concludes that exposure to digital media during adolescence is associated with altered development of brain connectivity involved in emotional regulation, reward processing, and cognitive control.

These findings suggest, according to the authors, a critical need for neuroscience-informed approaches to digital wellbeing during adolescent brain development.

The main one, among others, was a signal of activation of the ventral striatum associated with the use of digital media that exceeds the threshold of clinical significance.

The significance of this finding is that this pattern is consistent with neurobiological models of addiction and suggests that digital media platforms may be activating reward system mechanisms in ways that resemble  substance abuse patterns .

It is evident that regular social media users show an increasing activation of the reward system over time instead of the expected decrease in the development of reward sensitivity, as some  studies demonstrate .

This divergent trajectory suggests the possibility that exposure to digital media may impede the normal progression of development towards more mature reward processing patterns.

According to the authors of the study, “the persistence of adolescent reward hypersensitivity into adulthood could have significant implications for decision-making, risk-taking, and vulnerability to addictive processes throughout life.”

Furthermore, the increase in gray matter volume observed in certain areas, similar to that observed in substance use disorders, suggests that exposure to digital media can produce structural brain changes analogous to those  found  in addictive behaviors.

Adolescence: the transcendence of a stage of fragility.

Adolescence is a period of great importance in the integral development of the person, in their anatomical, physiological, endocrine and, above all, neurological dimensions: brain maturation at this stage will have implications in the construction of their future cognition, emotional regulation and behavior.

Thus, the processes of synaptic pruning, myelination, and functional reorganization that They are especially intense until about twenty years of age, representing a period of intense neuroplasticity on which the subsequent capacity for learning and adaptation will largely depend.

But it also implies a state of special vulnerability to environmental stimuli and the behaviors that can be adopted at this stage, which will shape,  for better or for worse , the neural architecture throughout life.

Currently, and this is the issue that concerns us and that is driving initiatives such as the one undertaken by the New York City Council, the unprecedented exposure of adolescents to digital media is creating a particularly aggressive environment for the proper neurodevelopment of their brains: an overabundance of gratifying stimuli unequivocally linked to screen exposure, along with the worrying lack of diversification towards other stimuli, such as non-virtual social relationships, exposure to the natural environment, reflective capacity and critical thinking or physical activity – digital overexposure leads to sedentary behavior – which offer a worrying outlook on the development of their future abilities.

Thus, as a result of this overexposure, symptoms common to any addictive behavior arise, such as disorders in motivation, attention, memory, cognitive and communicative ability, self-control and resilience, as well as depression, dependence, self-destructive tendencies or isolation.

Bioethical assessment

The enormous significance of the uncontrolled growth of exposure to digital media, especially in the most vulnerable ages such as childhood and adolescence, requires an urgent analysis and assessment of the advisability of its regulation or restriction, in the same way as is done with psychoactive substances or addictive behaviors.

If the brain patterns linked to excessive screen time show great similarities—as this recent meta-analysis shows—with those observed in known addictive behaviors, it seems unacceptable that drastic measures are not urgently adopted to prevent the abuse of digital media at any age, but specifically during periods of greater vulnerability, as already mentioned.

Education and training in the responsible use of digital media are necessary, but not sufficient. Strict regulation of access to certain media and content is essential, as is prosecuting those who use digital media to disseminate particularly addictive and destructive content, such as pornography, gambling, eating disorders, violence, and other harmful substances, which are all the more toxic the more vulnerable the recipient.

The defense of individual freedom of access to this content should not be considered unlimited. The disastrous consequences that toxic exposure to digital media can have on the exposed population—the majority of our adolescents and young adults—constitute a limiting factor for their free access, given the difficulty those affected have in assessing the significance of these negative effects, which can be permanent in many cases.

Responsibility for managing the enormous risk of overexposure to digital media affects everyone from families to regulatory bodies, including educational institutions and social media, which must be promptly informed of significant findings that, like the one we are now analyzing, reveal the most frightening side of behaviors that, because they are widespread, tend to become normalized without restriction.

Julio Tudela. Bioethics Observatory. Catholic University of Valencia