Forest Therapy and Mindfulness for Highly Sensitive Persons

Forest Therapy and Mindfulness in Highly Sensitive Persons (HSP): A Multicenter Randomized Interventional Study Over Approximately 22 Weeks

This randomized, multicenter interventional study evaluates a combined forest therapy (shinrin-yoku) and mindfulness-based program in adults with high sensory-processing sensitivity confirmed using a validated instrument. Participants are randomized (1:1) to either a forest-based intervention or an active indoor sensory control condition. The intervention is delivered over approximately 22 weeks according to a predefined protocol, with assessments conducted at baseline and at the end of the intervention.

This is a multicenter, randomized, parallel-group interventional study in adults with high sensory-processing sensitivity confirmed using a validated instrument. Participants are randomized 1:1 to one of two study arms at study entry and remain in their assigned group for the duration of the study.

Intervention delivery is standardized across participating sites through facilitator training and a predefined session manual. The experimental arm consists of structured sessions conducted in forest environments and includes guided walking, mindfulness-based practices, and structured sensory awareness activities, with facilitated group reflection. The active comparator arm consists of structured indoor group activities designed to match the experimental arm in duration, group interaction, and facilitator contact, without exposure to forest or outdoor natural environments.

Study procedures and assessment schedules are predefined in the protocol and implemented in accordance with applicable ethical requirements and Good Clinical Practice guidelines.

Inclusion Criteria:

• Age 18 to 65 years
• High sensory-processing sensitivity confirmed using a validated instrument (e.g., HSPS/Aron scale)
• Able to perform moderate physical activity (e.g., walking)
• Able to provide written informed consent

Exclusion Criteria:

• Severe psychiatric disorder or acute clinical instability
• Medical condition contraindicating moderate physical activity
• Use of medications with strong autonomic or neuroendocrine effects (e.g., high-dose systemic corticosteroids; selected beta-blockers)
• Recent participation in a structured mindfulness or forest-therapy program
• Pregnancy or unstable medical condition