Excessive mobile phone and artificial intelligence use have been associated, in recent studies, to symptoms such as anxiety, insomnia, difficulty concentrating, irritability and feelings of loneliness in adolescents. The relationship is still being discussed by the scientific community, but doctors recommend paying attention to changes in mood, sleep and social behaviour linked to screen use.
Marina, 16 years old, was brought to the consultation by her parents because she "won't put her phone down, not even to sleep". In recent weeks, she has had difficulty falling asleep, become more irritable with her family and said she prefers to chat with an artificial intelligence app rather than with her friends, because "it never judges". Cases like Marina's, repeated in surgeries and across screens throughout Brazil, have led researchers to investigate more thoroughly what intensive mobile phone and AI use may be doing to adolescents' brains and mood.
"The data and clinical case cited in this article are fictional and are merely illustrative, serving to facilitate understanding of the topic addressed."
What the studies show
The topic gained worldwide prominence with the book The Anxious Generation, by social psychologist Jonathan Haidt, which brought together data from various countries showing a significant increase in anxiety, depression and self-harm behaviours among adolescents from 2010 onwards, a period that coincides with the popularisation of the smartphone. According to this line of research, four factors would be behind the problem: less face-to-face social interaction, fewer hours and poorer quality of sleep, attention fragmented by constant notifications and a pattern of use that resembles addiction.
It is worth noting that this theory is not unanimous. Other researchers, analysing the same database in different countries, found no decline in life satisfaction or consistent increase in psychological symptoms during the same period, and point out that much of the evidence is correlational, that is, it shows that the two phenomena occurred together, but does not prove that one caused the other. This is currently an active and legitimate discussion within the scientific community, and will probably take several years before we have a more definitive answer.
Symptoms most associated with excessive screen use
Regardless of the debate on cause and effect, some symptoms appear frequently in studies and clinical reports linked to intensive mobile phone use:
- Difficulty initiating or maintaining sleep
- Irritability and mood swings
- Difficulty concentrating and decline in school performance
- Anxiety, mainly related to social comparison on networks
- Isolation from face-to-face social interaction
And artificial intelligence? A new chapter
Whilst mobile phones have been studied for more than a decade, the use of generative AI by adolescents is a recent phenomenon, and science is catching up. A study published at the end of 2025 in the journal BMJ identified that approximately one third of adolescents already uses AI tools for social interaction, and some report that these conversations are even more satisfying than conversations with real people — a finding that drew attention for its possible link to increased loneliness in this age group.
A RAND Corporation study, also from 2025, showed that approximately 1 in every 8 young Americans has already used generative AI to seek guidance on mental health — reaching almost 1 in every 4 among those aged 18 to 21. In light of this, the American Psychological Association issued an alert recommending caution: chatbots respond by predicting words probabilistically, which can simulate empathy, but without the clinical training necessary to deal with signs of crisis or provide a safe diagnosis.
What we still don't know
It is important to keep things in perspective: not every adolescent who uses their mobile phone a lot will develop a mental disorder, and technology also has a positive role — access to information, support for study routines, social connection at a distance. What science today points to with more certainty is not "mobile phones cause mental illness", but rather that there is an association significant enough to deserve the attention of parents, educators and doctors, especially when use is already affecting the adolescent's sleep, mood or social life.
When to seek help
It is worth seeking medical evaluation when mobile phone or AI use is accompanied by persistent changes in sleep, mood, appetite or school performance, or when technology seems to be replacing rather than complementing the adolescent's real relationships. A consultation, face-to-face or via telemedicine, helps to differentiate what is a phase, what is a habit to adjust and what may already be a warning sign.
Frequently asked questions
Do mobile phones and AI cause mental illness in adolescents? Science has not yet confirmed a direct cause-and-effect relationship. What exists are consistent associations between excessive use and symptoms such as anxiety, insomnia and loneliness, which deserve attention, but do not allow us to state that technology "causes" a mental disorder on its own.
What are the first warning signs? Changes in sleep pattern, irritability, social isolation and decline in school performance associated with screen time tend to be the first signs noticed by family and doctors.
Is using AI to talk things through safe? It may offer some occasional support, but AI tools do not replace professional evaluation, particularly in cases of more intense emotional distress or risk.
This content is informative and educational in nature and does not replace medical consultation, diagnosis or treatment. If you experience persistent symptoms, seek professional evaluation.
Dr Rebeca Soares Andrade CRM-GO 39335