Benefits of Outdoor Walks in Reducing Depressive Symptoms

Benefits of a Nature Walk vs. an Urban Walk in Reducing Depressive Symptoms: A Randomized Controlled Study Among College Students

The goal of this clinical trial is to determine whether outdoor walking in different environments-urban or natural-can reduce depressive symptoms among college students. The study also tests whether providing prompts for active engagement during nature walks enhances the benefits compared to unstructured nature walks.

Participants will be randomly assigned to one of three groups: (1) urban walk, (2) nature walk, or (3) active nature walk with guided interaction. Each participant will walk for 30 minutes, twice a week, for 3 weeks, complete questionnaires, and participate in interviews.

Our primary outcome (PHQ-9) will be used to test the following two primary hypotheses:

• Hypothesis 1: Participants in both nature walk conditions (combined) will show greater reductions in depressive symptoms (PHQ-9) than those in the urban walk group.
• Hypothesis 2: Participants in the active nature walk will show greater reductions than those in the regular nature walk.

The investigators aim to compare how walking in different outdoor environments influences depressive symptoms among college students. Specifically, the investigators will assess:

1. walking in an urban environment (like a busy city street),
2. walking in a natural environment regularly (e.g., walking without specific guidance), and
3. walking in a natural environment with guided interaction prompts (e.g., noticing birds, listening to sounds, touching flowers).

Standardized questionnaires will measure changes in depressive symptoms, anxiety, affect, cognitive flexibility, nature connection, and Presence across all three groups.

The investigators will also explore potential mechanisms behind any observed effects, including interaction patterns, presence, cognitive changes, and emotional responses to the different environments.

Inclusion Criteria:

• College students in Seattle
• Aged over 18.
• Having depressive symptoms with self-rated Patient Health Questionnaire-9 (PHQ-9) scored higher than 5.
• Normal or corrected-to-normal visual acuity.
• No identified hearing impairment.
• No history of neurological or mental disorders.

Exclusion Criteria:

• Receiving clinical psychiatric treatment or psychological counseling.
• Failing in providing consent form.