Summary: Researchers have identified nine blood-based microRNAs that are elevated in adolescents diagnosed with depression, offering a promising biomarker for earlier, more objective detection. These microRNAs were not observed in adult studies of depression, suggesting they may reflect biological processes specific to the adolescent brain.
The study used a minimally invasive dried blood spot method, making sample collection practical for routine screening and large-scale research. This approach could help identify teens at risk for persistent or treatment-resistant depression before symptoms escalate.
Key Facts:
- Distinct adolescent biomarkers: Nine microRNAs were elevated in teens with depression and appear not to overlap with markers reported in adult depression studies.
- Minimally invasive testing: Dried blood spots collected by a simple finger prick enable easy storage and transport, supporting scalable screening and longitudinal monitoring.
- Potential for early detection: These blood-based markers could complement clinical assessment, revealing biological risk before full clinical symptoms develop.
Source: McGill University
Using a novel laboratory protocol developed at McGill, researchers detected nine microRNAs in dried blood spot samples that were consistently elevated in adolescents diagnosed with depression. Several of these microRNAs also tracked with symptom severity over follow-up assessments.
“The rising incidence of adolescent depression is alarming, and when depression begins early it can have lasting, severe consequences,” said senior author Cecilia Flores, James McGill Professor in the Department of Psychiatry, researcher at the Douglas Research Centre and principal investigator at the Ludmer Centre. Adolescents with depression face higher risks of substance use, social isolation, and symptoms that may not respond well to standard treatments.
A minimally invasive and scalable approach
In collaboration with teams at the University of California, Los Angeles and Stanford University, the McGill researchers analyzed dried blood spot samples from 62 adolescents—34 diagnosed with depression and 28 psychiatrically healthy peers. Dried blood spots are collected with a simple finger prick, air-dried, and frozen. This method preserves molecular integrity while simplifying storage and transport, enabling broader application in clinical and research settings.
The McGill laboratory developed and optimized the small RNA sequencing protocol needed to extract and profile microRNAs from these low-volume dried blood samples. This technical advance makes peripheral microRNA profiling feasible in adolescents and supports longitudinal monitoring of biological changes associated with mental health.
“Dried blood spots offer a practical tool for psychiatric research,” said first author Alice Morgunova, postdoctoral fellow at McGill. “They enable minimally invasive sampling that can be repeated over time to track early biological signals linked to depression.”
Current depression diagnosis relies heavily on self-report and clinical interviews, which can delay detection if teens do not recognize symptoms or are reluctant to disclose them. A validated blood-based screening measure would provide an objective complement to clinical assessment and could help prioritize early intervention for at-risk adolescents.
The research team intends to replicate and extend these findings in larger, more diverse adolescent samples and to investigate how these microRNAs interact with genetic, developmental, and environmental risk factors for depression.
About the study
The study, titled “Peripheral microRNA signatures in adolescent depression,” was conducted by Alice Morgunova, Cecilia Flores and colleagues and published in Biological Psychiatry Global Open Science.
Funding: Support came from the Douglas Foundation and Bombardier Fund grant, the National Institute on Drug Abuse (NIH), the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada, the Healthy Brains for Healthy Lives initiative and related fellowships and collaborative awards supporting mental health research.
About this depression and genetics research news
Author: Keila DePape
Source: McGill University
Contact: Keila DePape – McGill University
Image: Image credited to Neuroscience News
Original Research: Open access. Title: Peripheral microRNA signatures in adolescent depression (DOI: 10.1016/j.bpsgos.2025.100505). Published by Cecilia Flores et al. in Biological Psychiatry Global Open Science.
Abstract
Peripheral microRNA signatures in adolescent depression
Background
Adolescent depression often leads to persistent functional impairment, chronic symptom severity, and reduced treatment responsiveness. Identifying peripheral epigenetic signatures that reflect neurodevelopmental pathways is critical for improving early prevention and intervention strategies. MicroRNAs are key epigenetic regulators of brain development, but their role as biomarkers or mediators of adolescent depression has been unclear.
Methods
The study profiled microRNAs from dried blood spot samples collected from clinically depressed and psychiatrically healthy male and female adolescents. Samples were processed and sequenced using a small RNA protocol optimized for microRNA identification, enabling reliable detection from low-volume, archived dried blood spots.
Results
Nine microRNAs were differentially expressed (adjusted p < 0.05), all showing higher expression in adolescents with depression. Several—miR-3613-5p, miR-30c-2, and miR-942-5p—were associated with greater depression severity at follow-up but did not track with anxiety symptoms, indicating specificity for persistent depressive symptoms. Expression of miR-32-5p inversely correlated with hippocampal volume, linking peripheral microRNA signals to potential neuroanatomic alterations. Predicted gene targets of these microRNAs are involved in neurodevelopment, cognition, and pathways implicated in depressive disorders.
Conclusions
This study establishes a set of peripheral microRNA markers associated with adolescent depression and supports the feasibility of using dried blood spots for scalable, longitudinal biomarker research. These findings provide a foundation for further validation work aimed at integrating biological markers into early detection and prevention strategies for youth mental health.