Effects of Hirudotherapy, Phytotherapy, and Forest Therapy in Adults With Reduced Work Capacity or Special Needs (CAM-HPMT)

Evaluation of the Biological Effects of Complementary and Alternative Health Care Services, Including Forest Therapy, Phytotherapy, and Hirudotherapy, in Individuals With Reduced Work Capacity and/or Special Needs

This interventional study will evaluate the effects of three complementary and alternative health care services-forest therapy, phytotherapy, and hirudotherapy-in individuals with a participation level below 55% and/or special needs. Participants will be assigned to one of three intervention groups or to a control group. The study will assess changes in blood pressure, body composition, handgrip strength, psychological well-being, perceived stress, and sleep quality before and after the intervention period. Safety, accessibility, feasibility, and acceptability of the services will also be evaluated. The findings will be used to develop standardized and evidence-informed recommendations for providing these services to people with reduced participation and/or special needs.

Study Overview

• Status: Active, not recruiting
• Conditions: Participation Level Below 55% and/or Special Needs
• Intervention / Treatment: Other: Phytotherapy; Behavioral: Forest Therapy; Procedure: Hirudotherapy

Detailed Description

This randomized controlled interventional study will evaluate the biological, functional, and psychosocial effects of complementary and alternative health care services in individuals with a participation level below 55% and/or special needs. The study is designed to generate evidence for the development of standardized, accessible, and evidence-informed protocols for forest therapy, phytotherapy, and hirudotherapy.

A total of 100 participants will be enrolled and allocated to four groups of approximately 25 participants each: a phytotherapy group, a forest therapy group, a hirudotherapy group, and a control group receiving no study-related complementary and alternative health care intervention. Participants in the phytotherapy group will receive three phytotherapy sessions, participants in the forest therapy group will receive ten forest therapy sessions, and participants in the hirudotherapy group will receive six hirudotherapy sessions. The interventions will be delivered by appropriately qualified and licensed practitioners in accordance with Lithuanian legal and professional requirements.

Assessments will be conducted before and after the intervention period. Physiological and functional assessments will include blood pressure, body composition, and handgrip strength. Psychosocial outcomes will include psychological well-being, perceived stress, and sleep quality, assessed using standardized questionnaires, including the WHO-5 Well-Being Index, the 10-item Perceived Stress Scale, and the Pittsburgh Sleep Quality Index. Pre-intervention and post-intervention outcomes will be compared within and between the intervention and control groups.

The study will also evaluate the feasibility, accessibility, safety, and acceptability of providing these services to individuals with reduced participation and/or special needs. Reasonable accommodations may include accessible locations, adapted information formats, assistance with transportation or mobility, and support from accompanying persons when required.

Participant safety will be monitored throughout the study. Eligibility, contraindications, and potential risks will be assessed before the interventions. Any adverse events or unexpected reactions will be documented and evaluated. Particular attention will be given to contraindications and safety requirements associated with phytotherapy and hirudotherapy.

The results will be used to prepare standardized methodological materials and practical recommendations for complementary and alternative health care practitioners, health promotion programs, and social inclusion services.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Lithuania
  • Klaipėda County
    • Klaipėda, Klaipėda County, Lithuania, LT-92294
      • Klaipeda University, Faculty of Health Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Individuals with a participation level below 55% and/or officially recognized special needs.

Ability and willingness to participate in the study procedures and assigned intervention.

Provision of written informed consent by the participant or, where applicable, by a legally authorized representative.

Ability to complete the planned assessments independently or with reasonable assistance.

Medical condition sufficiently stable to participate in the assigned complementary and alternative health care intervention.

Willingness to attend baseline and post-intervention assessments and the scheduled intervention sessions.

Exclusion Criteria:

Acute illness, fever, active infection, or clinically unstable health condition at the time of enrollment.

Any medical condition that, in the investigator's or intervention provider's judgment, would make participation unsafe.

Known contraindication to the intervention to which the participant may be assigned.

Current participation in another interventional study that could affect the study outcomes.

Inability to provide informed consent and absence of a legally authorized representative.

Inability to comply with the study procedures or intervention schedule despite reasonable accommodations.

Planned major medical procedure or substantial change in treatment during the study period that could influence the study outcomes.

Additional intervention-specific exclusion criteria:

Phytotherapy: known allergy or hypersensitivity to the planned herbal products; clinically relevant interactions with current medications; pregnancy or breastfeeding, when relevant to the selected herbal product; severe hepatic or renal impairment where the planned preparation may be contraindicated.

Hirudotherapy: bleeding disorders; clinically significant anemia; current anticoagulant or antiplatelet therapy when considered unsafe by the treating clinician; immunodeficiency; active skin infection or lesion at the planned application site; known allergy to leech-related substances; other contraindications identified by the licensed hirudotherapy practitioner.

Forest therapy: acute condition limiting safe participation outdoors; uncontrolled cardiovascular or respiratory symptoms; severe mobility, cognitive, behavioral, or sensory limitations that cannot be safely accommodated; severe allergy or environmental sensitivity relevant to the planned setting.

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Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Phytotherapy Group; Participants assigned to this arm will receive three phytotherapy sessions delivered by a qualified complementary and alternative health care practitioner. The services will use legally permitted and appropriately sourced herbal products in accordance with Lithuanian professional and safety requirements. Physiological, functional, and psychosocial outcomes will be assessed before and after the intervention period.	Other: Phytotherapy; Participants assigned to the phytotherapy arm will receive three individualized phytotherapy sessions delivered by a qualified complementary and alternative health care practitioner. The intervention may include assessment, selection, and use of legally permitted herbal preparations or herbal products appropriate to the participant's health status and special needs. Products will not be presented as investigational medicinal products. Contraindications, possible interactions, tolerability, and adverse reactions will be assessed and monitored throughout the intervention period.
Experimental: Forest Therapy Group; Participants assigned to this arm will receive ten structured forest therapy sessions delivered by a qualified forest therapy practitioner. Sessions will be adapted to participants' functional abilities and special needs and will be conducted in accessible natural environments. Physiological, functional, and psychosocial outcomes will be assessed before and after the intervention period.	Behavioral: Forest Therapy; Participants assigned to the forest therapy arm will receive ten structured forest therapy sessions delivered by a qualified forest therapy practitioner. Sessions will take place in accessible natural or forest environments and may include guided slow walking, sensory awareness, breathing, relaxation, mindful attention, and reflective activities. Session content and pace will be adapted to participants' functional abilities and special needs. Attendance, tolerability, and any adverse events will be documented.
Experimental: Hirudotherapy Group; Participants assigned to this arm will receive six hirudotherapy sessions delivered by a qualified and licensed hirudotherapy practitioner. Eligibility and contraindications will be assessed before treatment, and participant safety and adverse events will be monitored throughout the intervention period. Physiological, functional, and psychosocial outcomes will be assessed before and after the intervention period.	Procedure: Hirudotherapy; Participants assigned to the hirudotherapy arm will receive six hirudotherapy sessions delivered by a qualified and licensed practitioner. Before the intervention, eligibility and contraindications will be assessed. Medicinal leeches will be applied according to an individualized protocol, taking into account the participant's health condition and safety requirements. Participants will be monitored for bleeding, local skin reactions, infection, allergic reactions, and other adverse events during and after each session.
No Intervention: Control Group; Participants assigned to this arm will not receive a study-related complementary and alternative health care intervention during the study period. They will undergo the same baseline and post-intervention assessments as participants in the intervention groups.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Systolic Blood Pressure	Change in resting systolic blood pressure from baseline to the post-intervention assessment. Blood pressure will be measured in millimeters of mercury (mmHg) using a standardized procedure. A lower post-intervention value compared with baseline will indicate a reduction in systolic blood pressure.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Diastolic Blood Pressure	Change in resting diastolic blood pressure from baseline to the post-intervention assessment. Blood pressure will be measured in millimeters of mercury (mmHg) using a standardized procedure. A lower post-intervention value compared with baseline will indicate a reduction in diastolic blood pressure.	Baseline and after completion of the intervention period, approximately 3 months after baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Psychological Well-Being Assessed With the WHO-5 Well-Being Index	Change in psychological well-being from baseline to the post-intervention assessment, measured using the 5-item World Health Organization Well-Being Index (WHO-5). The raw score ranges from 0 to 25, with higher scores indicating better psychological well-being. The raw score may also be multiplied by 4 to obtain a percentage score ranging from 0 to 100.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Perceived Stress Assessed With the PSS-10	Change in perceived stress from baseline to the post-intervention assessment, measured using the 10-item Perceived Stress Scale (PSS-10). The total score ranges from 0 to 40, with higher scores indicating greater perceived stress.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Sleep Quality Assessed With the Pittsburgh Sleep Quality Index	Change in sleep quality from baseline to the post-intervention assessment, measured using the Pittsburgh Sleep Quality Index (PSQI). The global score ranges from 0 to 21, with higher scores indicating poorer sleep quality.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Handgrip Strength	Change in maximal handgrip strength from baseline to the post-intervention assessment. Handgrip strength will be measured in kilograms using a hand dynamometer under standardized testing conditions. Higher values indicate greater grip strength.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Body Fat Percentage	Change in body fat percentage from baseline to the post-intervention assessment, measured using a standardized body composition analyzer. Lower or higher values will be interpreted according to the participant's individual health status.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Body Weight	Change in body weight from baseline to the post-intervention assessment. Body weight will be measured in kilograms using a standardized body composition analyzer, with participants assessed under comparable measurement conditions.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Body Mass Index	Change in body mass index from baseline to the post-intervention assessment. Body mass index will be calculated as body weight in kilograms divided by height in meters squared and reported in kg/m².	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Skeletal Muscle Mass	Change in skeletal muscle mass from baseline to the post-intervention assessment. Skeletal muscle mass will be estimated in kilograms using a standardized bioelectrical impedance body composition analyzer under comparable measurement conditions.	Baseline and after completion of the intervention period, approximately 3 months after baseline
Change in Visceral Fat Level	Change in visceral fat level from baseline to the post-intervention assessment. Visceral fat will be estimated using a standardized bioelectrical impedance body composition analyzer and reported according to the device-specific visceral fat rating scale. Lower scores indicate a lower estimated level of visceral fat.	Baseline and after completion of the intervention period, approximately 3 months after baseline

Collaborators and Investigators

• Sponsor: Klaipėda University
• Investigators: Principal Investigator: Laura Zaliene, PhD, Klaipėda University

Publications and helpful links

General Publications

• Siah CJR, Goh YS, Lee J, Poon SN, Ow Yong JQY, Tam WW. The effects of forest bathing on psychological well-being: A systematic review and meta-analysis. Int J Ment Health Nurs. 2023 Aug;32(4):1038-1054. doi: 10.1111/inm.13131. Epub 2023 Mar 2.
• Qiu Q, Yang L, He M, Gao W, Mar H, Li J, Wang G. The Effects of Forest Therapy on the Blood Pressure and Salivary Cortisol Levels of Urban Residents: A Meta-Analysis. Int J Environ Res Public Health. 2022 Dec 27;20(1):458. doi: 10.3390/ijerph20010458.
• Hosseini M, Jadidi A, Derakhshan Barjoei MM, Salehi M. Applications of leech therapy in medicine: a systematic review. Front Med (Lausanne). 2024 Sep 16;11:1417041. doi: 10.3389/fmed.2024.1417041. eCollection 2024.
• Lauche R, Cramer H, Langhorst J, Dobos G. A systematic review and meta-analysis of medical leech therapy for osteoarthritis of the knee. Clin J Pain. 2014 Jan;30(1):63-72. doi: 10.1097/AJP.0b013e31828440ce.

Study record dates

Study Major Dates

• Study Start (Actual): April 15, 2026
• Primary Completion (Estimated): December 20, 2026
• Study Completion (Estimated): December 20, 2026

Study Registration Dates

• First Submitted: July 13, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 16, 2026

Study Record Updates

• Last Update Posted (Actual): July 16, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Sleep Quality; Blood Pressure; Forest Therapy; Phytotherapy; Perceived Stress; Handgrip Strength; Psychological Well-Being; Hirudotherapy; Special Needs; Complementary and Alternative Health Care; Reduced Participation
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Behavior; Personal Satisfaction; Sleep Initiation and Maintenance Disorders; Psychological Well-Being; Therapeutics; Mind-Body Therapies; Complementary Therapies; Relaxation Therapy; Phytotherapy; Forest Therapy; Leeching
• Other Study ID Numbers: CAM-SN-HFT-2026-01; SAM-003-K-0002 (Other Grant/Funding Number: Ministry of Health of the Republic of Lithuania)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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