Researchers at McGill University have discovered nine molecules in the blood that are linked to depression in teenagers. These molecules, called microRNAs, were found at higher levels in teens diagnosed with depression. The same molecules also helped predict how their symptoms might change over time.
This discovery could help doctors detect depression earlier. Early diagnosis is important because symptoms can worsen and become harder to treat.
Depression is increasing among adolescents. When it starts young, it can have serious and long-lasting effects. Teens with depression often face problems like substance abuse, social isolation, and symptoms that do not respond well to treatment.
Cecilia Flores, a senior researcher and professor at McGill, led the study. She explained that the nine microRNAs found in teens have not been linked to depression in adults. This suggests that teen depression may involve unique biological processes.
The study was done with researchers from UCLA and Stanford. It included 62 teenagers—34 with depression and 28 without. The team collected small blood samples from the participants using a simple finger prick. The blood was dried and frozen to keep it stable for later testing.
This method is minimally invasive and easy to use. It also allows samples to be stored and sent to labs without problems. The McGill researchers developed the lab technique to extract and study microRNAs from these dried blood spots.
Alice Morgunova, the study’s first author and a postdoctoral fellow at McGill, said the new method could become a useful tool in mental health research. It could help track early changes in the body linked to depression without causing discomfort.
Currently, depression is mostly diagnosed based on how patients describe their symptoms. This can delay treatment, especially if teenagers do not recognize or want to talk about their feelings. A blood test like this could offer a clearer, objective way to find teens at risk.
The researchers plan to test their findings with more teens and learn how these molecules interact with genes and life experiences.
The full study, titled “Peripheral microRNA signatures in adolescent depression,” was published in the journal Biological Psychiatry Global Open Science.
This research was supported by several organizations, including the Douglas Foundation, the National Institute on Drug Abuse, the Canadian Institutes of Health Research, and others, as part of McGill University’s Healthy Brains for Healthy Lives initiative.
