A new study from Boston Children’s Hospital reveals that social withdrawal and a preference for loneliness in adolescents can cause measurable changes in brain structure and function. The findings, published on October 2, 2025, in the journal Cerebral Cortex (DOI: 10.1093/cercor/bhaf260), underscore the importance of social interactions for healthy brain development during adolescence and offer new avenues for early interventions.
Social Isolation and Its Effects on the Brain
Adolescence is a critical period of social reorientation, during which young people shift their focus from family to peers and larger social networks. This transition is essential for development, but it also makes adolescents vulnerable to social stressors. Dr. Caterina Stamoulis and her team at Boston Children’s Hospital found that adolescents who socially withdraw or frequently prefer loneliness exhibit structural and functional changes in several brain regions. These include the insular cortex and the anterior cingulate cortex, which are crucial for social and emotional processes.
The study utilized data from the Adolescent Brain Cognitive Development (ABCD) Study, funded by the National Institutes of Health, which examines 11,880 adolescents across 21 sites in the U.S. The researchers analyzed MRI and fMRI data from nearly 3,000 adolescents whose parents reported on their social behaviors. The results indicate that socially withdrawn adolescents have weaker connections in brain networks that support social behavior, decision-making, and other cognitive functions. These changes span multiple networks, suggesting an increased risk for mental health issues.
“Social isolation doesn’t just affect regions responsible for social functions, but also other cognitive processes,” Stamoulis explains. “The widespread effects on the brain suggest that social withdrawal may increase the risk for mental illness.”
Implications for Clinical Practice
The findings have important implications for clinicians. While some degree of withdrawal is normal in adolescence, persistent patterns of isolation warrant special attention. “If we can show parents and families what’s happening in their children’s brains, we can help them understand the risks,” says Stamoulis. Early identification of social withdrawal could enable clinicians to develop preventive strategies that promote mental well-being and build resilience.
Long-Term Observation and Next Steps
The ABCD study allows participants to be examined again every two years, giving Stamoulis and her team the opportunity to track the development of these brain changes over time. "We can now observe how the brain develops and compare it with adolescents who do not exhibit these behavioral patterns," explains Stamoulis. The next phase of research will investigate whether persistent social isolation leaves lasting marks on the brain and how early interventions can influence this course.
The study was supported by the National Science Foundation and provides new insights into how social interactions shape brain development. The researchers hope their work will help develop more effective strategies for supporting adolescent mental health.
Source:
Boston Children’s Hospital
Cerebral Cortex
DOI: 10.1093/cercor/bhaf260
Keywords:
Social isolation, Adolescence, Brain development, Neuroimaging, Mental health
