Analysis of 120 older adults from the landmark FINGER trial reveals that baseline brain architecture determines how individuals respond to multimodal lifestyle interventions for dementia prevention. Researchers used unsupervised clustering to identify distinct cortical thickness and subcortical volume patterns, finding that participants with different grey matter profiles showed markedly different responses to the two-year intervention targeting diet, exercise, cognitive training, and vascular health management. This finding addresses a critical gap in understanding why lifestyle interventions show variable efficacy across populations. The heterogeneity in brain structure among at-risk individuals has long confounded intervention studies, making it difficult to predict who will benefit most from preventive strategies. By identifying neuroanatomical subtypes, this work could enable precision medicine approaches to dementia prevention, allowing clinicians to tailor interventions based on individual brain patterns rather than applying one-size-fits-all protocols. The implications extend beyond the FINGER protocol to potentially optimize any lifestyle-based prevention strategy. However, the relatively small sample size and focus on a specific demographic—older adults with cardiovascular risk factors—limits broader generalizability. This represents an important step toward personalized prevention strategies that could dramatically improve outcomes in the pre-clinical dementia population.