Depression Shows Brain-Linked Gene Signals in White Blood Cells

A study of 1,864 people with major depressive disorder and 1,208 controls found 1,383 genes with altered activity in white blood cells, including 18 synapse-related genes that reliably separated depressed individuals from healthy ones. Seven of these genes were also altered in mood-related brain regions, suggesting a systemic, body-wide link between depression and immune biology. The work is exploratory and does not establish causation, but points to potential blood-based biomarkers and new avenues for research and treatment targeting inflammation.