An updated roadmap for brain-mental health associations in the UK Biobank

The UK Biobank presents a significant opportunity to explore the connections between brain imaging and mental health on a large scale. However, the strength and consistency of these associations are still uncertain. In a study involving 8,415 participants, researchers examined 17,580 imaging-derived phenotypes from seven MRI techniques in relation to 309 mental health indicators.

These associations were found to be generally weak, with a median correlation coefficient of 0.018. Even the strongest associations fell within the top 1% range at 0.108. The replication of these findings was poor, with only 9.0% of significant associations in the initial testing also appearing in subsequent validation. Among mental disorders, eating disorders exhibited the strongest associations, although they were confirmed in just 6.0% of cases.

Substance use disorders, on the other hand, demonstrated the highest replication rate at 14.5%. Susceptibility-weighted imaging showed the most reliable brain-mind connections. Changes in brain structure and mental health over time showed only a weak relationship. To assist researchers in navigating these findings, an interactive online tool is provided that displays the effect sizes and replication benchmarks for any combination of mental health categories and imaging methods, aiding in the selection of appropriate variables and study designs in UK Biobank research.