Depression that begins in young adulthood carries a significantly stronger hereditary component and a higher risk of suicide attempts than depression that develops later in life, a new study published in Nature Genetics has found.
The research, conducted by Karolinska Institutet and collaborating institutions across the Nordic region, underscores the urgent need for more targeted prevention strategies in mental health care.
“We hope that genetic information will be able to help healthcare professionals identify people at high risk of suicide, who may need more support and closer follow-up,” said Lu Yi, senior researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, and one of the study’s corresponding authors.
Drawing on medical records and genetic data from more than 150,000 individuals with depression and 360,000 controls in Denmark, Sweden, Norway, Finland and Estonia, the researchers compared the genetic architecture of early-onset depression (before age 25) with depression diagnosed after age 50.
The differences were striking. The team identified twelve genetic regions associated with early-onset depression, compared with just two linked to late-onset cases. Individuals with a high genetic predisposition to early-onset depression were found to be at markedly greater risk: one in four had attempted suicide within a decade of their diagnosis—double the rate seen in those with low genetic risk.
“We show that early-onset depression has partly different genetic causes than depression that affects older individuals and that the risk of suicide attempts is increased,” said Yi. “This is an important step towards precision medicine in psychiatry, where treatment and preventive measures are tailored to each individual.”
The researchers plan to explore how these genetic distinctions relate to brain development, stress exposure and life experiences. They also aim to determine whether genetic risk profiles could be incorporated into clinical suicide-prevention strategies.
The study ‘Genome-wide association analyses identify distinct genetic architectures for early-onset and late-onset depression’, involved teams from Karolinska Institutet, the University of Oslo, Copenhagen University Hospital, Roskilde University, the University of Tartu and the Nordic research network TRYGGVE.
It was funded by organisations including the European Research Council and the US National Institute of Mental Health. Some authors report collaborations with pharmaceutical companies, though none were related to the current project.
