16.06.2025.
Are we shaped more by our genes or by the experiences we go through in life? A new large-scale study suggests it’s not an either-or question — but a combination of both, with one influencing how we respond to the other.
Researchers analysed data from nearly 22,000 identical twins across 11 different studies to explore how genes and environment interact in shaping mental health. The findings, published in the journal Nature Human Behaviour, suggest that genetic factors influence how sensitive we are to our life experiences — and that this sensitivity plays a role in the development of conditions like depression, anxiety, ADHD, and others.
Why twins?
Identical twins share nearly the same genetic code. This makes them an ideal group for studying how differences in the environment — such as trauma, stress, parenting styles, or life events — affect people, even when their DNA is nearly identical.
What researchers found was that even among identical twins, differences in mental health outcomes often came down to how sensitive their genes made them to environmental influences. In short:
- Twins with a higher genetic sensitivity to their environment were more likely to show different mental health outcomes, depending on what they experienced in life.
- Twins with lower genetic sensitivity were more similar to each other in traits and outcomes — even if their experiences differed.
Gene-environment links to mental health
The study identified several links between specific gene types and environmental sensitivity, including:
- Genes related to stress reactivity were associated with a higher risk of depression.
- Genes that regulate stress hormones were linked to psychotic-like experiences.
- Growth-related genes were connected with autistic traits.
Researchers say this helps explain why two people might go through similar experiences — such as childhood adversity or stressful work environments — but be affected in very different ways.
One person may develop anxiety or depression, while another might not. Part of the explanation lies in the genetic “filter” through which we each process experience.
What does this mean for mental health?
This research doesn’t suggest that genes alone determine mental health. Nor does it downplay the impact of environmental factors like trauma, relationships, or social conditions. Rather, it highlights that genetic sensitivity acts as a bridge between experience and mental health, making some people more or less affected by what happens to them.
Understanding this interaction could, in the long term, help develop more personalised approaches to mental health support, by identifying those who may be more vulnerable to environmental stressors.
For now, the study adds valuable insight into how nature and nurture are closely linked, helping us better understand why mental health is such a complex and individual matter.
