Post-intervention neuroimaging effects of psychosocial interventions aimed at promoting resilience in children and adolescents under psychological stress: A systematic review.

Childhood and adolescence are neurodevelopmentally critical periods, during which psychological adversity can increase the risk of subsequent mental health difficulties. However, the increased neuroplasticity during this window also confers potential for developing resilience, which is now seen as a dynamic process of adapting to adversity. This pre-registered systematic review (PROSPERO-CRD42024537715) summarises the post-intervention neuroimaging outcomes of non-invasive, non-pharmacological interventions aimed at promoting resilience in samples with a mean age of < 25 years exposed to any explicit psychological stress. Studies involving traumatic or focal brain lesions were excluded. MEDLINE, PsycINFO and CENTRAL databases were searched from inception to 14/7/2024. Magnetic Resonance Imaging (MRI) outcomes were the primary focus. Risk of bias was assessed against adapted Joanna Briggs Institute checklist items. A narrative synthesis was conducted due to study heterogeneity. We identified 13 eligible studies: 1 reporting structural and diffusion-weighted MRI (performed after 2 years of intervention), 1 resting-state fMRI (14 years after end of intervention) and 11 task-based fMRI metrics (ranging from immediately post-intervention to 8 years after end of intervention). Resilience interventions reduce limbic activity (thalamus, amygdala and right anterior insula) in task-based fMRI. In older adolescents, social, mindfulness, and exercise interventions strengthen Prefrontal Cortex(PFC)-limbic connectivity, decreasing limbic activity. Evidence in younger adolescents is sparse, showing mixed effects on PFC-limbic connectivity. Five studies were at high risk of bias; the most common limitation was no pre-intervention MRI scans. Overall, this study summarises promising mechanisms, as demonstrated on neuroimaging, through which resilience can be enhanced in stressed youth through psychosocial interventions.