What happens in the brain during adolescence? : A systematic review of gray and white matter changes during adolescence

Abstract: During adolescence, the brain undergoes significant reorganization due to myelination and synaptic pruning. These changes are associated with risk-taking behaviors and the development of social relationships. Recent advancements in adolescent brain development can potentially enhance strategies for preventing and treating mental health disorders. This systematic review focuses on structural changes in the adolescent brain, specifically emphasizing a decrease in gray matter and an increase in white matter changes. Four longitudinal MRI studies were included in this systematic review to identify changes in brain volume among healthy adolescents with an age range of 10 to 19 years. The results revealed observable changes in gray and white matter volume in various brain regions during this period. A decrease in gray matter was observed in the frontal, temporal, and parietal cortex, and several subcortical regions. Contrary to our expectations, the amygdala displayed an increase in gray matter in early adolescence. We expected this findings to occur in late childhood. The results also indicated that males undergo more significant changes in the brain during this period than females. Considering the Social Process Network (SIPN) and triadic model, changes occurring in the frontal cortex and the amygdala could be linked to social behavior. While the changes in the thalamus, hippocampus, and amygdala may be linked to heightened risk-taking and mental health disorders. Further research is necessary to clarify the relationship between mental health disorders, behaviors, and developmental processes during adolescence.