The Effectiveness of Nature-Based Therapies for Anxiety and Depression in Adolescents

Development and Evaluation of the Effectiveness of Nature-Based Therapies in the Treatment of Anxiety and Depression Symptoms: An Adolescent Population Sample

This three-phase study first assesses the prevalence of anxiety and depressive symptoms among adolescents, then evaluates the effectiveness of a randomized controlled nature-based therapy intervention. The final phase explores emotional, behavioral, and psychosocial changes through qualitative interviews with parents of adolescents in the intervention group. The study aims to provide evidence for nature-based therapies as effective complementary interventions for adolescent mental health.

Study Overview

• Status: Completed
• Conditions: Depression; Anxiety
• Intervention / Treatment: Behavioral: Nature-Based Therapy

Detailed Description

This study aims to determine the prevalence of anxiety and depressive symptoms among adolescents, evaluate the effectiveness of a structured nature-based therapy (NBT) intervention, and explore psychosocial changes observed in adolescents through parental perspectives. Adolescence represents a critical developmental period marked by intense biological, emotional, and cognitive transitions that increase vulnerability to internalizing disorders such as anxiety and depression. When not addressed early, these symptoms may persist into adulthood and result in long-term psychological impairment.

The research is conducted using a three-phase mixed-methods design. In the first phase, a large-scale screening is implemented to assess the prevalence of anxiety and depressive symptoms within the adolescent population using standardized psychological assessment tools. This stage aims to identify individuals at elevated risk and determine eligibility for the intervention phase.

The second phase consists of a randomized controlled trial in which eligible participants are randomly assigned to either an experimental group receiving the nature-based therapy program or a control group receiving standard follow-up without therapeutic intervention. The nature-based therapy program is delivered in natural outdoor environments and incorporates experiential activities, group-based therapeutic exercises, emotional regulation practices, mindfulness-oriented techniques, and reflective components. The intervention is designed to enhance psychological well-being, reduce stress, improve emotional coping skills, strengthen social interaction, and promote adaptive functioning. Anxiety and depression levels are assessed at baseline, post-intervention, and follow-up to evaluate treatment effectiveness.

The third phase involves qualitative semi-structured interviews conducted with parents of adolescents who participated in the intervention group. These interviews aim to explore observed emotional, behavioral, social, and relational changes in adolescents following the therapy process. This qualitative component provides an in-depth understanding of therapeutic outcomes and supports the quantitative findings through parental observations.

Primary outcome measures include changes in anxiety and depressive symptom severity, while secondary outcomes focus on improvements in emotional regulation, psychosocial functioning, and overall psychological well-being. It is hypothesized that adolescents participating in the nature-based therapy program will demonstrate significant symptom reduction and enhanced psychosocial outcomes compared to the control group.

This study seeks to contribute robust empirical evidence regarding the clinical effectiveness of nature-based therapeutic interventions for adolescent mental health and to support their integration as accessible, holistic, and developmentally appropriate treatment approaches within mental health services.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Muş
    • Muş, Muş, Turkey (Türkiye), 49100
      • Outdoor Natural Settings (Nature-Based Therapy Sites)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adolescents within the defined age range of the study
• Not having a psychiatric diagnosis
• Not receiving psychological or psychiatric support
• Not having a physical disability that would limit participation in therapy sessions
• Having obtained parental consent to participate in the study

Exclusion Criteria:

• Presence of severe psychiatric disorders requiring immediate clinical intervention (e.g., psychosis, severe suicidal risk)
• Ongoing intensive psychological or psychiatric treatment during the study period
• Physical or medical conditions limiting participation in outdoor activities
• Cognitive impairments preventing comprehension of intervention activities

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Nature-Based Therapy Intervention Group; Participants assigned to this arm will receive a structured nature-based therapy program delivered in outdoor natural environments. The intervention includes experiential therapeutic activities, emotional regulation exercises, mindfulness-based practices, and group interaction sessions aimed at reducing anxiety and depressive symptoms and improving psychosocial functioning.	Behavioral: Nature-Based Therapy; The nature-based therapy program is a structured psychosocial intervention conducted in outdoor natural environments for adolescents experiencing anxiety and depressive symptoms. The program combines experiential activities in nature with therapeutic techniques including emotional regulation practices, mindfulness-based exercises, reflective discussions, and group-based interactions. Sessions emphasize active engagement with natural surroundings to support stress reduction, emotional awareness, attention regulation, and social connectedness. Therapeutic components aim to strengthen adaptive coping strategies, enhance psychological resilience, and improve interpersonal functioning within a supportive group setting. The intervention follows a standardized session framework to ensure consistency while allowing flexibility based on developmental needs.
No Intervention: Control Group; Participants assigned to the control group will not receive the nature-based therapy intervention during the study period and will continue with their usual daily routines. They will undergo the same assessment schedule as the intervention group, including baseline, post-intervention, and follow-up measurements to allow for comparative evaluation of outcomes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anxiety and Depression Symptom Severity	Changes in anxiety and depressive symptom severity will be assessed using standardized psychological assessment scales administered at baseline, post-intervention, and follow-up to evaluate the effectiveness of the nature-based therapy program.	Baseline (22.06.2025), post-intervention (27.07.2025), and Follow-up (27.10.2025) (Exactly 3 months after the last intervention program.)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Environmental Attitudes Toward Nature	Change in adolescents' environmental attitudes and responsible environmental behaviors will be assessed using the Environmental Behavior Scale for Middle and High School Students, developed by Ardahan (2022). This self-report instrument consists of 13 items and 3 subscales designed to measure environmentally responsible behaviors and daily habits related to nature. Items are rated on a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). Higher total scores indicate greater environmental sensitivity and more frequent pro-environmental behaviors. The unit of measure is total score change from baseline to post-intervention and follow-up. The scale has demonstrated good internal consistency (Cronbach's alpha = 0.88).	Baseline (22.06.2025), post-intervention (27.07.2025), and follow-up (27.10.2025) (Exactly 3 months after the last intervention program.)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Parent-Reported Psychosocial Changes Supporting Quantitative Outcomes	Qualitative data will be collected through semi-structured interviews with parents of adolescents in the intervention group to explore emotional, behavioral, social, and functional changes observed following the nature-based therapy program. The qualitative findings will be used to complement and contextualize the quantitative outcome measures, providing a comprehensive understanding of intervention effects.	Qualitative interviews with parents were conducted within one week of the last intervention assessment. Date: 28.07.2025 - 03.08.2025

Collaborators and Investigators

• Sponsor: Muş Alparslan University
• Investigators: Principal Investigator: Murat GENÇ, PhD, Muş Alparslan University

Publications and helpful links

General Publications

• Cuijpers, P., Sijbrandij, M., Koole, S. L., Andersson, G., Beekman, A. T., & Reynolds III, C. F. (2013). The efficacy of psychotherapy and pharmacotherapy in treating depressive and anxiety disorders: A meta-analysis of direct comparisons. World psychiatry, 12(2), 137-148.
• Bratman, G. N., Hamilton, J. P., & Daily, G. C. (2012). The impacts of nature experience on human cognitive function and mental health. Annals of the New York academy of sciences, 1249(1), 118-136.
• Ulrich, R. S., Simons, R. F., Losito, B. D., Fiorito, E., Miles, M. A., & Zelson, M. (1991). Stress recovery during exposure to natural and urban environments. Journal of environmental psychology, 11(3), 201-230.
• Kaplan, R., & Kaplan, S. (1989). The experience of nature: A psychological perspective. Cambridge university press.
• Hansen, M. M., Jones, R., & Tocchini, K. (2017). Shinrin-yoku (forest bathing) and nature therapy: A state-of-the-art review. International journal of environmental research and public health, 14(8), 851.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Actual): August 3, 2025
• Study Completion (Actual): November 3, 2025

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 20, 2026

Study Record Updates

• Last Update Posted (Actual): February 20, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: depression; adolescent; anxiety; prevalence; Nature-based therapy
• Additional Relevant MeSH Terms: Mental Disorders; Behavioral Symptoms; Behavior; Anxiety Disorders; Depression
• Other Study ID Numbers: MSU-SGLK-MG-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared to protect participant confidentiality and in accordance with ethical research guidelines and informed consent agreements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No