A test for depression in teenagers 🥺

Using a new laboratory method they developed, researchers from McGill University have identified nine molecules with elevated concentrations in the blood of teenagers diagnosed with depression. With these molecules, the research team was also able to predict the progression of symptoms.


The results of the clinical study could help detect the illness before symptoms worsen and become difficult to treat.

"It is alarming to see that more and more teenagers are being diagnosed with depression, and when depression starts early, its effects can be severe and long-lasting," says Cecilia Flores, lead author, James McGill Professor in the Department of Psychiatry at McGill University, researcher at the Douglas Research Centre, and principal investigator at the Ludmer Centre. "Teenagers with depression are more likely to have substance abuse problems, suffer from social isolation, and experience symptoms that are often difficult to treat."

Interestingly, the nine molecules—called "microRNAs"—were not associated with depression in adults, suggesting they reflect biological processes specific to teenagers.

A minimally invasive and scalable approach

Conducted in collaboration with the University of California, Los Angeles, and Stanford University, the study involved 62 teenagers: 34 with depression and 28 without. The research team collected small blood samples, allowed them to dry, and then froze them to preserve their molecular integrity. These types of samples, which are easy to store and transport, are collected through a simple finger prick—a practical and scalable approach.

The McGill University team developed the laboratory method used to extract and analyze the microRNAs from the samples.

"Our findings pave the way for the use of dried blood spots in psychiatric research. This is a convenient and minimally invasive way to detect early biological changes related to mental health," explains Alice Morgunova, lead author and postdoctoral fellow at McGill University.

Diagnosing depression primarily relies on symptoms reported by affected youth, which, according to the authors, can delay treatment, especially if teenagers do not recognize the signs or are unwilling to talk about them. A blood screening tool could provide an additional, more objective measure for identifying vulnerable teenagers.

The researchers plan to validate their findings in larger groups of teenagers and explore possible links between these microRNAs and genetic and environmental risk factors.