Effects of Darkness Retreat: a Pilot Study

NCT07429617 | Recruiting

• 1 other identifier: SWPS_Retreat_RCT_1
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 2

Brief Summary

The primary goal of this pilot study is to test the feasibility and safety of a research protocol for a voluntary darkness retreat. The study will also allow for a preliminary examination of the psychological effects of the retreat. The investigators will investigate whether participants experience changes in their well-being and ruminative style, whether these changes persist over time, and if these effects are moderated by individual characteristics such as readiness for change or subjective evaluation of the experience as well as frequency of participants' monitoring. Participants will be randomly assigned to one of two experimental groups, both of which will spend 3 days and 3 nights in seclusion. These groups will differ only in the frequency of psychological monitoring during the retreat, allowing us to compare the effectiveness and safety of each protocol.

Conditions

Study Protocol Feasibility; Non Clinical Anxiety; Non Clinical Worry; Non Clinical Rumination

Keywords

sensory deprivation; darkness retreat; protocol feasibility; Anxiety; Mindfulness

Outcome Measures

Primary Outcomes (2)

• Study Protocol Feasibility

  Feasibility will be assessed based on participant recruitment and retention rates, adherence to the intervention schedule, completeness of data collection at all time points, and occurrence of any adverse events during the darkness retreat.

  From recruitment start until completion of the six-month follow-up.

• Penn State Worry Questionnaire Score Change

  The total sum score of the Polish version of the Penn State Worry Questionnaire.

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

Secondary Outcomes (8)

• CESD-R Score Change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

• State-Trait Anxiety Inventory Score Change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

• Abbreviated Five Facet Mindfulness Questionnaire Score Change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

• Ruminative Thoughts Questionnaire Score Change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after f the intervention. Time point 3: Six months after the previous measurement (time point 2).

• Meaning in Life Questionnaire Score Change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

Other Outcomes (4)

• Personal Development Initiative Scale score change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

• Client Satisfaction Questionnaire score change

  Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

• Credibility/Expectations Questionnaire score change

  Time point 1: Just prior to the intervention. Time point 2: Immediately after the intervention. Time point 3: Six months after the previous measurement (time point 2).

Study Arms (2)

Low-frequency monitoring

EXPERIMENTAL

Participants assigned to the low-frequency monitoring arm will receive one structured (full) psychological consultation per day throughout the three-day darkness retreat. Consultations will follow a standardized interview protocol focusing on emotional state, safety assessment, and participant well-being. Each session will be conducted without direct visual or physical contact, taking place through a wall separating the participant's cabin from the adjacent monitoring room. Consultations will coincide with meal delivery to minimize disruption of the retreat experience.

Other: Darkness Retreat - Several Days of Seclusion in Complete Darkness

High-frequency monitoring

EXPERIMENTAL

Participants assigned to the high-frequency monitoring arm will receive three psychological consultations per day during the three-day darkness retreat: one full structured interview and two shorter check-ins. All consultations will follow a predefined protocol to ensure consistency, with the full interview assessing emotional state, safety, and well-being, and the shorter check-ins focusing on brief status updates and safety screening. As in the low-frequency condition, there will be no direct visual or physical contact; all interactions will take place through a wall separating the participant's cabin from the monitoring room. Consultations will be scheduled approximately every three hours during waking hours to allow for more detailed and time-sensitive data collection

Other: Darkness Retreat - Several Days of Seclusion in Complete Darkness

Interventions

Darkness Retreat - Several Days of Seclusion in Complete Darkness OTHER

The intervention is a voluntary darkness retreat involving three days and three nights of continuous seclusion in a completely dark cabin, with no access to external light sources or electronic devices. During the retreat, participants are consulted about their well-being through a standardized interview protocol, with consultation frequency determined by their assigned group. Participants in both groups will be equipped with WHOOP wristbands - devices monitoring physiological activity. These wristbands will serve a dual purpose: From a research perspective, they will provide access to biological data- circadian rhythm patterns and heart rate variability, offering deeper insights into the physiological processes accompanying the darkness retreat experience. From a safety perspective, they will enable real-time monitoring of participants' condition, supporting one of the main goals of the pilot study: ensuring participant safety while assessing the feasibility of the procedure.

High-frequency monitoring; Low-frequency monitoring

Eligibility Criteria

• Age: 30 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Participants must obtain a total score between 40 and 80. (40-59 = moderate level of worry/anxiety) (60-80 = high level of worry/anxiety)
• In cases where participants fall within the high range, if clinical levels of worry are identified during the clinical interview, they will be excluded from participation.
• PAtient Health Questionnaire-9 (PHQ-9, range 0-27, higher scores indicating worse functioning): Individuals scoring above 10 will be considered at elevated risk for depression, and those scoring 20 or higher will not be invited to the clinical interview.
• Generalized Anxiety Disorder-7 (GAD-7, range 0-21, higher scores indicating worse functioning): Individuals scoring 7 or higher will be classified as having elevated generalized anxiety symptoms, and those scoring 15 or higher will be excluded from further participation.
• Alcohol Use Disorders Identification Test (AUDIT, range 0-40, higher scores indicating worse functioning): Individuals scoring above 8 will be considered at elevated risk for problematic drinking, and those scoring 22 or higher will not be invited to the clinical interview.
• Drug Use Disorders Identification Test (DUDIT, range 0-44, higher scores indicating worse functioning): Individuals scoring above 4 will be classified as at elevated risk for substance use, and those scoring 7 or higher will be excluded.
• DSM-5 - Panic Disorder (range 0-40, higher scores indicating worse functioning): score ≥ 26 DSM-5 - Social Anxiety Disorder (range 0-40, higher scores indicating worse functioning): score ≥ 26 DSM-5 - Post-Traumatic Stress Disorder (range 0-44, higher scores indicating worse functioning): score \> 22
• Only individuals who are not excluded based on the above criteria will be invited to the next stage.
• Stage II. Candidates meeting the preliminary criteria will be invited to an online clinical interview with a psychologist. Approximately one week before the scheduled interview, participants will receive via email a link to the Personality Beliefs Questionnaire (PBQ; Zawadzki et al., 2017), that would help in a more in-depth assessment of psychological functioning during the actual meeting. In order to exclude clinical cases, the psychologist will use the structured clinical interview M.I.N.I. (Mini International Neuropsychiatric Interview)
• Participants who complete the psychological interview-regardless of their final qualification for the study-will receive a compensation of approximately 200 ZŁ in shopping vouchers (50EUR).

Sponsors & Collaborators

• University of Social Sciences and Humanities, Warsaw: lead
• Within Properties: collaborator

Study Sites (2)

Poznań Laboratory of Affective Neuroscience, Institute of Psychology, SWPS University, Warsaw, Poland

Poznan, Wielkopolska, 61-719, Poland

RECRUITING

SWPS University of Social Sciences and Humanities

Poznan, Poland

RECRUITING

Related Publications (4)

• Soláriková, P., Bartolen, I. (2025). Effects of chamber restricted environmental stimulation therapy on state mindfulness, physiological regulation and emotional experience in young adults: Exploring variations by resting heart rate variability. Acta psychologica, 253, 104697. https://doi.org/10.1016/j.actpsy.2025.104697

  BACKGROUND

• Hruby, H., Schmidt, S., Feinstein, J. S., Wittmann, M. (2024). Induction of altered states of consciousness during Floatation-REST is associated with the dissolution of body boundaries and the distortion of subjective time. Scientific Reports, 14, 9316. https://doi.org/10.1038/s41598-024-59642-y

  BACKGROUND

• Flux, M. C., Fine, T. H., Poplin, T., Al Zoubi, O., Schoenhals, W. A., Schettler, J., Refai, H. H., Naegele, J., Wohlrab, C., Yeh, H.-W., Lowry, C. A., Levine, J. C., Smith, R., Khalsa, S. S., Feinstein, J. S. (2022). Exploring the acute cardiovascular effects of Floatation-REST. Frontiers in Neuroscience, 16. https://doi.org/10.3389/fnins.2022.995594

  BACKGROUND

• Feinstein, J. S., Khalsa, S. S., Yeh, H., Al Zoubi, O., Arevian, A. C., Wohlrab, C., Pantino, M. K., Cartmell, L. J., Simmons, W. K., Stein, M. B., Paulus, M. P. (2018). The elicitation of relaxation and interoceptive awareness using floatation therapy in individuals with high anxiety sensitivity. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 3(6), 555-562. https://doi.org/10.1016/j.bpsc.2018.02.005

  BACKGROUND

MeSH Terms

Conditions

Anxiety Disorders

Condition Hierarchy (Ancestors)

Mental Disorders

Central Study Contacts

Jarosław M Michałowski, Professor

CONTACT

+48 694 441 722; jmichalowski@swps.edu.pl

Katarzyna Sanna, PhD

CONTACT

+48601363388; ksanna@swps.edu.pl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: During the study, participants will not be informed that its primary aim is to compare two variants of the psychological monitoring protocol-more frequent versus less frequent-in terms of their impact on worry levels and overall psychological well-being. This information will be withheld to minimize the risk of expectancy effects, which could distort participants' responses and reduce the reliability of the collected data. Due to the nature of the study, it is not possible to obtain valid results while fully informing participants about this aspect in advance. Disclosing this information during participation could influence how they experience the retreat and report their well-being. To ensure the highest ethical standards, a debriefing procedure will be carried out after the study has been completed (i.e., after the follow-up assessment and prior to the anonymization of data). Participants will be fully informed about the actual aim of the study and the methodological approach used.
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: Participants will be randomly assigned to one of two parallel intervention arms: (1) low-frequency monitoring (one structured psychological consultation (full consultation) per day) or (2) high-frequency monitoring (three consultations per day: one full and two shorter check-ins). Participants remain in their assigned arm for the full duration of the retreat (three days and three nights). Both groups undergo the intervention during the same study period, and no crossover between conditions occurs.

Study Record Dates

• First Submitted: December 16, 2025
• First Posted: February 24, 2026
• Study Start: October 16, 2025
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): November 1, 2026
• Last Updated: February 24, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: IPD and supporting documents will be available as soon as research results are published.
• Access Criteria: IPD and supporting documents will be publicly available.

Locations

PL (2)