The largest study followed 943,027 people from birth
Denmark followed nearly a million people from birth. Children who grew up with the least greenery around home had more psychiatric diagnoses later - up to 55% more.
Well-supported by good-quality research. how we score evidence
Caveat on this rating: Strong design, still not causal, and the authors say so: "Despite the strong longitudinal design of our study, our risk estimates fundamentally only show correlations." Three limits they name: residential choice may be genetically confounded; unmeasured socioeconomic factors such as green-space quality and crime rates may remain; and NDVI "provides no information about the use of green space", so a child who only sees a park scores the same as one who plays in it daily. Our own added critique: there is no sibling or within-family analysis, so families who move somewhere greener are never compared with their own relatives. The 55% figure is the paper's "up to" across various disorders, not a single headline estimate.
Denmark followed nearly a million people from birth. Children who grew up with the least greenery around home had more psychiatric diagnoses later. Up to 55% more than those who grew up with the most.
Significant findings
Researchers measured how green each childhood address was using satellite images, then matched that against the national psychiatric register. Nobody had to remember anything or fill in a survey.
943,027 people. Followed from birth into adulthood.
They tested the obvious objection: money. Parents' income, education and jobs, family psychiatric history, and how built-up the area was. The pattern barely moved.
That makes this the strongest single finding in the field.
Worth asking
It is still a correlation, and the authors say so plainly - their estimates "fundamentally only show correlations."
A greener address also comes with quieter streets and cleaner air. The next stop asks what "green" is really measuring.
Source
Residential green space in childhood is associated with lower risk of psychiatric disorders from adolescence into adulthood — Engemann K, Pedersen CB, Arge L, Tsirogiannis C, Mortensen PB, Svenning J-C (2019)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1073/pnas.1807504116
DOI: 10.1073/pnas.1807504116
How this was scored
- Study design
- Cohort study
- Funding
- Independently funded
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 943,027
- Preregistered
- No
- Conflicts disclosed
- Yes
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 31, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "strong evidence". Well-supported by good-quality research. It scores 74 out of 100 on our published rubric. One caveat travels with that badge: Strong design, still not causal, and the authors say so: "Despite the strong longitudinal design of our study, our risk estimates fundamentally only show correlations." Three limits they name: residential choice may be genetically confounded; unmeasured socioeconomic factors such as green-space quality and crime rates may remain; and NDVI "provides no information about the use of green space", so a child who only sees a park scores the same as one who plays in it daily. Our own added critique: there is no sibling or within-family analysis, so families who move somewhere greener are never compared with their own relatives. The 55% figure is the paper's "up to" across various disorders, not a single headline estimate. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Residential green space in childhood is associated with lower risk of psychiatric disorders from adolescence into adulthood — Engemann K, Pedersen CB, Arge L, Tsirogiannis C, Mortensen PB, Svenning J-C (2019). Published in: Top-tier peer-reviewed journal. DOI: 10.1073/pnas.1807504116. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Cohort study. Funding: Independently funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.