Stress (Psychology)NCT07508800
Effects of Brief Nature Exposure on Brain Functioning and Stress Reactivity
An observational study of Stress (Psychology), run by National Institutes of Health (NIH) at 1 site in United States.
Trial summary
This study is focused on understanding the impact of time spent in nature (relative to an urban control) on stress, neural, and cardiac functioning in people experiencing high levels of stress, depression, and anxiety. Read more about this study
- Who is it for?
- Ages 18 to 25 years
- Conditions the study is for
- Stress (Psychology)
- What is being tested?
- Nature vs. Urban walks
- How many people
- 4 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2026to 30 Jun 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 25 years
- All sexes
- No healthy volunteers
- Adult
Study population: Individuals endorsing high stress levels will be recruited from the community and UCSF clinician outreach through flyer, media advertisements. Current or past depressive and anxiety disorders, if present, will be included due to their high prevalence and overlap with perceived stress.
Who may be able to join
- Meets cut-off for high level of perceived stress on PSS-10 during screening (>27 total score); Current or past depressive and anxiety disorders, if present on SCID-5 assessment, will be ncluded due to their high prevalence and overlap with perceived stress
- Normal, or corrected to normal, vision (due to the visual nature of the EEG tasks)
- If on psychotropic medication, stable regime for > 1 month
Who cannot join
- Major medical conditions with CNS sequelae (e.g., seizure disorders, multiple sclerosis, significant, uncontrolled cardiovascular pathology) Past or present neurological problems (including seizures and head trauma resulting in neurological or cognitive sequelae)
- IQ estimate <75 on the Test of Premorbid Functioning
- Current or past history of severe mental illness (e.g., bipolar schizophrenia spectrum disorder, or current or past history of substance use disorders
Trial locations and contacts
1 site in 1 country.
United States1 site
University of San Francisco California OR San Francisco VA Medical Center
San Francisco, California, 94122
About this study
Official title: YONDER Study (Effects of Brief Nature Exposure on Brain Functioning and Stress Reactivity)
This study is focused on understanding the impact of time spent in nature (relative to an urban control) on stress, neural, and cardiac functioning in people experiencing high levels of stress, depression, and anxiety.
Read the detailed description
Associations between urbanization and mental illness have long been recognized, but the mechanistic pathways underlying this association are not well understood and likely multifactorial. Reduced contact with nature may contribute to the increased psychopathology observed in urban environments.
Theories implicating attention restoration and stress reduction functions via cognitive control and reward brain networks have been proposed to explain how natural environments may decrease stress and promote mental health, particularly in individuals with high-stress loads who are at-risk for developing mental illness. However, most research examining nature's effects on mental health have been observational in design, leaving open questions about nature's effects on neural functioning. Well-controlled studies of brain responses to natural environments will inform stakeholders about potential cognitive and health benefits of nature, as well as guide development of clinical applications like parks prescriptions and nature-based behavioral interventions for individuals who may benefit. This team science grant will enable pilot data collection and a novel collaboration combining faculty expertise in pediatric nature-basedinterventions, clinical neuroscience of reward and motivation, electrophysiological biomarkers of psychiatric vulnerability and integrative healthcare. Further, our team will tap the policy and stewardship expertise of parks system leadership. This project's goal is to conduct a pilot clinical neuroscience study to establish a novel academic-community collaboration and support a larger project proposal to examine neurophysiological mechanisms underlying nature-based clinical interventions to improve mental health in individuals experiencing stress-based symptoms.
- Conditions
- Stress (Psychology)
- Being tested
- Nature vs. Urban walks
- Keywords
- nature; eeg; reward processing ; attention functioning, stress
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nature vs. Urban walksOther
We will evaluate the impact of spending time in nature vs. an urban control on EEG-based measures of reward and attention and resting heart rate variability
| Study group | Role | What they receive |
|---|---|---|
| Within-group study | individuals endorsing current high stress levels Receives: Other: Nature vs. Urban walks |
What is being measured
The primary outcome is the main question the study is designed to answer.
Brain functioning
EEG (neural) measures of attention and reward processing ; resting EEG (including frequency-based analyses of canonical frequency bands, e.g., gamma, beta, alpha, delta, theta) and event-related potential measures (reflecting attention, e.g, P300 and reward/affective processing, e.g., reward positivity, late positive potential).
Measured: ~1 hour after walking condition
Heart Rate Variability
This measure reflect the variation in heart beat rate, over time. Specifically we will measure heart rate during the EEG recordings and calculate the RMSSD (Root Mean Square of Successive Differences) of heartbeat R-R intervals.
Measured: ~ 1 hour after walking manipulaation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Apr 2026
- Study start1 Jan 2026
- Primary completion30 Jun 2026
- Study completion30 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Stress (Psychology)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case crossover
- Time perspective
- Prospective
- Enrolment
- 4 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Institutes of Health (NIH)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Principal investigator, Susanna Fryer, PhD, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07508800
- Sponsor's protocol ID
- UCSF
- Other IDs
- UCSF
- Status last verified
- Jul 2026
- First submitted
- 17 Mar 2026
- Last updated
- 23 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: This is a small pilot study largely aimed at generating pilot data for a larger (NIH) application; the applications these data support will propose data sharing
Study at a glance
From the registry record, last updated by the sponsor on 23 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- YONDER Study (Effects of Brief Nature Exposure on Brain Functioning and Stress Reactivity)
- ClinicalTrials.gov ID
- NCT07508800
- Acronym / sponsor ID
- UCSF
- Conditions
- Stress (Psychology)
- Keywords
- nature; eeg; reward processing ; attention functioning, stress
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 4 participants (actual)
- Lead sponsor
- National Institutes of Health (NIH)US National Institutes of Health
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 30 Jun 2026 (actual)
- Study completion
- 30 Jun 2026 (actual)
- First posted
- 2 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is focused on understanding the impact of time spent in nature (relative to an urban control) on stress, neural, and cardiac functioning in people experiencing high levels of stress, depression, and anxiety.
Detailed description
Associations between urbanization and mental illness have long been recognized, but the mechanistic pathways underlying this association are not well understood and likely multifactorial. Reduced contact with nature may contribute to the increased psychopathology observed in urban environments.
Theories implicating attention restoration and stress reduction functions via cognitive control and reward brain networks have been proposed to explain how natural environments may decrease stress and promote mental health, particularly in individuals with high-stress loads who are at-risk for developing mental illness. However, most research examining nature's effects on mental health have been observational in design, leaving open questions about nature's effects on neural functioning. Well-controlled studies of brain responses to natural environments will inform stakeholders about potential cognitive and health benefits of nature, as well as guide development of clinical applications like parks prescriptions and nature-based behavioral interventions for individuals who may benefit. This team science grant will enable pilot data collection and a novel collaboration combining faculty expertise in pediatric nature-basedinterventions, clinical neuroscience of reward and motivation, electrophysiological biomarkers of psychiatric vulnerability and integrative healthcare. Further, our team will tap the policy and stewardship expertise of parks system leadership. This project's goal is to conduct a pilot clinical neuroscience study to establish a novel academic-community collaboration and support a larger project proposal to examine neurophysiological mechanisms underlying nature-based clinical interventions to improve mental health in individuals experiencing stress-based symptoms.
Study design
- Observational model
- Case crossover
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Within-group study | – | Other: Nature vs. Urban walksindividuals endorsing current high stress levels |
Who may qualify
- Ages
- 18 to 25 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Individuals endorsing high stress levels will be recruited from the community and UCSF clinician outreach through flyer, media advertisements. Current or past depressive and anxiety disorders, if present, will be included due to their high prevalence and overlap with perceived stress.
Key inclusion criteria (3 listed)
- Meets cut-off for high level of perceived stress on PSS-10 during screening (>27 total score); Current or past depressive and anxiety disorders, if present on SCID-5 assessment, will be ncluded due to their high prevalence and overlap with perceived stress
- Normal, or corrected to normal, vision (due to the visual nature of the EEG tasks)
- If on psychotropic medication, stable regime for > 1 month
Key exclusion criteria (3 listed)
- Major medical conditions with CNS sequelae (e.g., seizure disorders, multiple sclerosis, significant, uncontrolled cardiovascular pathology) Past or present neurological problems (including seizures and head trauma resulting in neurological or cognitive sequelae)
- IQ estimate <75 on the Test of Premorbid Functioning
- Current or past history of severe mental illness (e.g., bipolar schizophrenia spectrum disorder, or current or past history of substance use disorders
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nature vs. Urban walksWe will evaluate the impact of spending time in nature vs. an urban control on EEG-based measures of reward and attention and resting heart rate variability | Other | Within-group study |
Primary outcome
Brain functioning
Time frame: ~1 hour after walking condition
EEG (neural) measures of attention and reward processing ; resting EEG (including frequency-based analyses of canonical frequency bands, e.g., gamma, beta, alpha, delta, theta) and event-related potential measures (reflecting attention, e.g, P300 and reward/affective processing, e.g., reward positivity, late positive potential).
Heart Rate Variability
Time frame: ~ 1 hour after walking manipulaation
This measure reflect the variation in heart beat rate, over time. Specifically we will measure heart rate during the EEG recordings and calculate the RMSSD (Root Mean Square of Successive Differences) of heartbeat R-R intervals.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jul 2026.
- Individual participant dataSharing planned: Undecided. This is a small pilot study largely aimed at generating pilot data for a larger (NIH) application; the applications these data support will propose data sharing
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Stress (Psychology), run by National Institutes of Health (NIH) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Brain functioning (time frame: ~1 hour after walking condition). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jul 2026.