Summary: New research indicates that depression that begins before age 25 carries a substantially stronger genetic component than depression that appears later in life. By analyzing genetic data and medical records from more than 150,000 people diagnosed with depression across Nordic biobanks, investigators pinpointed genetic regions specifically associated with early-onset cases and linked higher genetic risk to an increased probability of suicide attempts.
People with a high polygenic risk for early-onset depression were roughly twice as likely to attempt suicide within ten years of their first diagnosis compared with those at low genetic risk. These results emphasize a critical window for early identification and intervention and suggest genetics could eventually inform more targeted suicide-prevention strategies in clinical care.
Key Facts
- Stronger early genetic influence: Depression beginning before age 25 shows a more pronounced hereditary component than depression with onset after age 50.
- Elevated suicide risk: One in four individuals in the highest early-onset genetic risk group attempted suicide within ten years, about double the rate observed in the lowest risk group.
- Distinct genetic loci: The study identified twelve genomic regions associated with early-onset depression and two regions associated with late-onset depression.
Source: Karolinska Institute
Overview
A multinational team led in part by researchers at Karolinska Institutet examined how genetic architecture differs between depression that starts in young adulthood and depression that begins later in life. Published in Nature Genetics, the study combines genome-wide data and longitudinal health records from Denmark, Sweden, Norway, Finland and Estonia to compare early-onset major depressive disorder (eoMDD) and late-onset major depressive disorder (loMDD).
Study design and main findings
The analysis drew on more than 150,000 individuals diagnosed with depression and approximately 360,000 population controls. Cases were stratified by age at first diagnosis: early onset (<25 years) and late onset (>50 years). The researchers performed genome-wide association analyses to detect loci that differ between these clinically distinct groups.
They identified twelve genomic loci significantly associated with early-onset depression and two loci associated with late-onset depression. Genetic correlation between the two subtypes was moderate (rg ≈ 0.58), indicating that while there is overlap, substantial subtype-specific genetic architecture exists. The early-onset subtype also showed genetic correlations with traits and developmental pathways consistent with brain development.
Importantly, polygenic risk scores (PRS) calculated for early-onset depression predicted subsequent suicide attempts: individuals in the top PRS decile had an absolute risk of 26% for attempting suicide within ten years of diagnosis, compared with 12% in the bottom decile and 20% in the intermediate group.
Clinical and public health implications
These results highlight that age at onset identifies biologically meaningful subtypes of depression. Early-onset depression appears to carry a distinct developmental genetic signature and greater hereditary loading, which may partly explain the elevated risk of severe outcomes such as suicide attempts.
The findings support further research into integrating genetic risk profiling with clinical information to improve early detection, stratify risk, and tailor follow-up and prevention efforts. The authors emphasize that genetic information would not replace clinical judgment but could complement existing assessments to identify individuals who may benefit from intensified monitoring and targeted interventions.
Next steps
Researchers plan to investigate how the identified genetic differences relate to brain development, stress responses and life-course exposures. Ongoing work will explore whether and how genetic risk profiles for early-onset depression can be responsibly and effectively applied in healthcare settings for suicide prevention and personalized treatment planning.
The study represents a collaboration among Karolinska Institutet (Sweden), University of Oslo (Norway), Copenhagen University Hospital and Roskilde University (Denmark), the University of Tartu (Estonia) and the Nordic TRYGGVE research network.
Funding: The project received support from bodies including the European Research Council (ERC) and the U.S. National Institute of Mental Health. Some authors report collaborations with pharmaceutical companies, but none are related to this specific study; refer to the full scientific article for detailed conflict-of-interest statements.
Key Questions Answered:
A: Depression beginning before age 25 shows a stronger genetic influence than depression that starts later, and this early-onset subtype is associated with a higher risk of suicide attempts.
A: Individuals in the highest decile of polygenic risk for early-onset depression had about a 26% absolute risk of attempting suicide within ten years, roughly double the risk seen in the lowest decile.
A: The findings support a move toward precision psychiatry: combining genetic profiles with clinical data may help clinicians identify high-risk patients who require closer monitoring, tailored treatment or preventive measures.
Editorial Notes:
– This article was prepared by a Neuroscience News editor.
– The underlying journal paper was reviewed in full by the editorial team.
– Additional explanatory context was added by staff for clarity.
About this genetics and mental health research news
Author: Press Office
Source: Karolinska Institute
Contact: Press Office – Karolinska Institute
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Genome-wide association analyses identify distinct genetics architectures for early-onset and late-onset depression” by Lu Yi et al., published in Nature Genetics. See the scientific article for full methods, results and declarations.
Abstract
Genome-wide association analyses identify distinct genetics architectures for early-onset and late-onset depression
Major depressive disorder (MDD) is a common, heterogeneous condition with complex causes. Identifying more homogeneous subgroups based on clinical features—such as age at onset—can improve discovery of underlying genetic drivers and support development of targeted treatments.
Using Nordic biobanks linked to long-term health registries, the study compared early-onset MDD (eoMDD; n = 46,708 cases) with late-onset MDD (loMDD; n = 37,168 cases). Twelve genomic loci were identified for eoMDD and two for loMDD. The two subtypes showed a moderate genetic correlation (rg = 0.58) and differed in their genetic relationships with related traits, pointing to partially distinct genetic signatures and a developmental brain signature for early-onset cases.
Crucially, polygenic risk scores for eoMDD predicted suicide attempts within ten years following the initial diagnosis: absolute risk for suicide attempt was 26% in the top PRS decile, 12% in the bottom decile and 20% in the intermediate group. These findings can inform precision psychiatry approaches for MDD.