Researchers Identify Blood Markers for Teen Depression

McGill University researchers have identified nine blood-based molecules that not only distinguish teens with depression from those without but may also predict the course of their symptoms. The findings, published in the journal Molecular Psychiatry, open the door to earlier, more objective detection of depression in young people—potentially before symptoms worsen and become more resistant to treatment.

Using a novel lab method, they team analyzed dried blood samples from 62 teenagers—34 diagnosed with depression and 28 without. The identified molecules, known as microRNAs, were significantly elevated in teens with depression and, importantly, have not been previously linked to adult depression. This suggests they may reflect biological processes unique to adolescent mental health.

The research highlights the promise of a minimally invasive and scalable diagnostic tool. Samples were collected with a simple finger prick, dried, and frozen—an approach that preserves molecular integrity while simplifying storage and transport.