Effects of Forest Therapy on Physical and Psychological Parameters in the General Population - a Randomized Controlled Trial

In recent years, nature and forest therapy has increasingly become the focus of medical research. Recent scientific findings indicate overall positive effects of nature and forest therapy on physical and mental health. In Asia and Australia, it has already been implemented as a public health concept of prevention and health promotion. The aim of the project is to replicate the experience gained in Asia over the last three decades on the physical and psychological effects of nature/forest therapy in the context of the German forest and to investigate it further scientifically.

Study Overview

• Status: Recruiting
• Conditions: General Population (no Specific Condition or Disease)
• Intervention / Treatment: Behavioral: Active forest therapy; Behavioral: Passive forest therapy

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Berlin, Germany, 14109
    • Recruiting
    • Charité Hochschulambulanz für Naturheilkunde am Immanuel Krankenhaus
    • Contact: Miriam Rösner, Study nurse; Phone Number: 00493080505682; Email: m.roesner@immanuel.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

- Ability to Consent

Exclusion Criteria:

• Serious acute or chronic illness
• Immobility or limitation of mobility due to orthopedic, neurologic, or other medical causes
• Participation in another study
• Serious mental illness
• Pregnancy and lactation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Waiting list
Experimental: Active forest therapy	Behavioral: Active forest therapy; Participants take part in a two-hour active clinical forest therapy in Berlin-Wannsee on two days (with a break day in between). In this setting, a trained clinical forest therapist teaches exercises on the perception of nature and the connection between nature and health.
Active Comparator: Passive forest therapy	Behavioral: Passive forest therapy; Participants take part in a two-hour passive clinical forest therapy in Berlin-Wannsee over two days (with a break day in between). In this setting, a trained clinical forest therapist will guide participants to various locations in the forest where participants can stay and let nature have its effect on them.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Profile of Mood States (POMS)	Change from baseline POMS score at 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Profile of Mood States (POMS)		Baseline, day 1, day 3, 1 week, 3 months
Perceived Benefits of Nature Questionnaire (PBNQ)		Baseline, 1 week, 3 months
Subjective Vitality Scale state (SVS-G state)		Baseline, day 1, day 3, 1 week, 3 months
Complaint List (B-LR)		Baseline, 1 week, 3 months
Perceive Stress Questionaire (PSQ)		Baseline, day 1, day 3, 1 week, 3 months
Freiburger Fragebogen zur Achtsamkeit (FFA)		Baseline, 1 week, 3 months
Hospital Anxiety and Depression Scale (HADS)	The scale ranges from 0 to 3. Higher scores correspond to higher levels of anxiety and/or depression.	Baseline, 1 week, 3 months
Perceived Stress Scale (PSS)	The scale ranges from 0 to 4. Higher scores correspond to higher levels of perceived stress.	Baseline, 1 week, 3 months
Allgemeine Selbstwirksamkeit Kurzskala (ASKU)	The scale ranges from 1 to 5. Higher scores correspond to better outcomes.	Baseline, 1 week, 3 months
State-Trait Anxiety Inventory (STAI)	The scale ranges from 1 to 8. Higher scores correspond to higher levels of anxiety (after recoding three inverted items).	Baseline, day 1, day 3, 1 week, 3 months
PROMIS Scale v1.2 - Global Health	The scale ranges from 1 to 5, where 1 is the lowest level and 5 is the highest level. Higher scores reflect better functioning.	Baseline, 1 week, 3 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart Rate Variability (HRV)	24h measuring by Faros 180	Baseline, 1 week
Qualitative interviews	Qualitative assessment will be carried out in qualitative interviews in 20 patients participating in the study. The interviews will be recorded, transcribed and analyzed with qualitative content analysis.	1 week and 8 weeks after inclusion

Collaborators and Investigators

• Sponsor: Charite University, Berlin, Germany

Study record dates

Study Major Dates

• Study Start (Actual): October 10, 2022
• Primary Completion (Estimated): June 1, 2025
• Study Completion (Estimated): August 1, 2025

Study Registration Dates

• First Submitted: September 28, 2022
• First Submitted That Met QC Criteria: September 28, 2022
• First Posted (Actual): September 30, 2022

Study Record Updates

• Last Update Posted (Actual): May 31, 2025
• Last Update Submitted That Met QC Criteria: May 27, 2025
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: KWT2

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No