Transcranial Photobiomodulation in Anxiety Disorders

May 11, 2026 updated by: Francisco Gonzalez-Lima, PhD

Effects of Transcranial Photobiomodulation and Attention Bias Modification on Anxiety Symptoms and Brain Hemodynamics

The investigators have previously shown that safe, non-invasive methods of brain stimulation such as the administration of transcranial infrared light can result in improvements to cognition and emotion. The investigators hypothesize that transcranial photobiomodulation (tPBM) can be used in conjunction with attention bias assessment and modification to reduce anxiety symptoms in individuals with sub-clinical anxiety.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The investigators will conduct two studies: one examining the efficacy of transcranial photobiomodulation as a standalone treatment to alleviate sub-clinical anxiety symptoms and another evaluating the role of transcranial photobiomodulation as an adjunct to a form of cognitive behavioral therapy in anxiety treatment. The investigators will recruit individuals with sub-clinical anxiety and use attention bias assessment (ABA) to assess levels of anxiety, and then use attention bias modification (ABM) to reduce levels of anxiety. Brain activity will be monitored using functional near-infrared spectroscopy (fNIRS).

An online prescreen questionnaire will be used to determine participant eligibility. No medical records are accessed/obtained for verifying inclusion/exclusion criteria. Informed consent is obtained during the first in-person visit. Participants fill out questionnaires to assess their medical history and anxiety/depression symptoms. The participants then participate in either ABA or ABA/ABM while wearing the fNIRS headset before and after transcranial photobiomodulation treatment or sham. Both studies will comprise three in-person visits with an online follow-up a week later. In this single-blind, sham-controlled experiment, block randomization will be performed to minimize selection bias and allocation bias.

Study Type

Interventional

Enrollment (Estimated)

280

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Texas
      • Austin, Texas, United States, 78712
        • Recruiting
        • The University of Texas at Austin
        • Contact:
        • Principal Investigator:
          • Francisco Gonzalez-Lima, Ph.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18 years of age and older
  • State-Trait Anxiety Index (STAI) questionnaire score between 40-59 (indicates moderate sub-clinical anxiety)
  • Patient Health Questionnaire (PHQ-9) score between 1-9 (indicates minimal to mild sub-clinical depression)

Exclusion Criteria:

  • STAI score less than 40 or greater than 59
  • PHQ-9 score greater than 9
  • Medication instability (i.e., medication change within 6 weeks)
  • Indicated suicidal ideation
  • Currently receiving tPBM treatment
  • Current pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Arm 1: attention bias assessment (ABA), transcranial photobiomodulation (tPBM)
Participants will receive attention bias assessment (ABA) in conjunction with active transcranial photobiomodulation (tPBM) treatment to the forehead.
Behavioral: Attention bias assessment and modification
Attention bias assessment and modification involve two versions of the dot-probe task. These tasks are based on the premise that repeated attention shifts can retrain attentional biases, with the expectation that reducing attentional bias toward threats will alleviate sub-clinical anxiety symptoms.
Device: Transcranial photobiomodulation
Participants will receive near-infrared light at 1064 nanometers to the right side of the forehead for 8 minutes. The investigators have introduced this form of transcranial photobiomodulation (tPBM) as a means of human cognitive enhancement, and as an adjunct for attention bias modification for the reduction of symptoms of depression. In the present study, the investigators wish to extend these findings to the use of attention bias modification for the reduction of sub-clinical anxiety.
Sham Comparator: Arm 2: attention bias assessment (ABA), sham tPBM
Participants will receive attention bias assessment (ABA) in conjunction with sham (laser light off) transcranial photobiomodulation (tPBM) treatment to the forehead.
Behavioral: Attention bias assessment and modification
Attention bias assessment and modification involve two versions of the dot-probe task. These tasks are based on the premise that repeated attention shifts can retrain attentional biases, with the expectation that reducing attentional bias toward threats will alleviate sub-clinical anxiety symptoms.
Active Comparator: Arm 3: attention bias assessment and modification (ABA/ABM), transcranial photobiomodulation (tPBM)
Participants will receive attention bias assessment plus attention bias modification (ABA/ABM) in conjunction with active transcranial photobiomodulation (tPBM) treatment to the forehead.
Behavioral: Attention bias assessment and modification
Attention bias assessment and modification involve two versions of the dot-probe task. These tasks are based on the premise that repeated attention shifts can retrain attentional biases, with the expectation that reducing attentional bias toward threats will alleviate sub-clinical anxiety symptoms.
Device: Transcranial photobiomodulation
Participants will receive near-infrared light at 1064 nanometers to the right side of the forehead for 8 minutes. The investigators have introduced this form of transcranial photobiomodulation (tPBM) as a means of human cognitive enhancement, and as an adjunct for attention bias modification for the reduction of symptoms of depression. In the present study, the investigators wish to extend these findings to the use of attention bias modification for the reduction of sub-clinical anxiety.
Sham Comparator: Arm 4: attention bias assessment and modification (ABA/ABM), sham tPBM
Participants will receive attention bias assessment plus attention bias modification (ABA/ABM) in conjunction with sham (laser light off) transcranial photobiomodulation (tPBM) treatment to the forehead.
Behavioral: Attention bias assessment and modification
Attention bias assessment and modification involve two versions of the dot-probe task. These tasks are based on the premise that repeated attention shifts can retrain attentional biases, with the expectation that reducing attentional bias toward threats will alleviate sub-clinical anxiety symptoms.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Composite cognitive score in the dot-probe task
Time Frame: Visit 1 (baseline), Visit 2 (three days after Visit 1), Visit 3 (1 week after Visit 2)
The participant pays attention to a fixation cross in the center of the screen, which is followed by the presentation of two images on the left and right of the screen. One of these new images is a "threat" image, while the other is neutral. Following each trial of stimuli presentation, a probe type ("<" vs. ">") will randomly appear in the same location previously occupied by either the threatening or neutral image and remain on the screen until the participant has responded. Participants respond to the probe type by pressing the "←" or the "→" arrow key, respectively, on the keyboard, as quickly but as accurately as possible. The probe randomly replaces the neutral or the negative stimulus with equal frequency (50/50). The single primary outcome is the composite cognitive score which is calculated on the basis of performance in this task.
Visit 1 (baseline), Visit 2 (three days after Visit 1), Visit 3 (1 week after Visit 2)
Change in concentration of oxygenated hemoglobin as measured by functional near-infrared spectroscopy
Time Frame: Visit 1 (baseline), Visit 2 (three days after Visit 1), Visit 3 (1 week after Visit 2)
Hemodynamic activity is assessed non-invasively using near-infrared spectroscopy. In this procedure, a participant wears an apparatus on the head which contains an array of light sources and detectors. Light is applied to the surface of the skin, and a small fraction of the light passes through the underlying tissue and reflects back to the surface, where it is detected and the number of photons at specific light wavelengths are counted by a computer. This photon count can be converted to changes in concentration of metabolic indices, such as oxygenated/deoxygenated hemoglobin.
Visit 1 (baseline), Visit 2 (three days after Visit 1), Visit 3 (1 week after Visit 2)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Francisco Gonzalez-Lima, PhD

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2025

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

September 1, 2028

Study Registration Dates

First Submitted

July 24, 2025

First Submitted That Met QC Criteria

August 13, 2025

First Posted (Actual)

August 21, 2025

Study Record Updates

Last Update Posted (Actual)

May 14, 2026

Last Update Submitted That Met QC Criteria

May 11, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00007224

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

What data will be shared? Individual participant data that underlie the results reported in this study, after deidentification (text, tables, figures, and appendices).

A data dictionary, including a description of the variables and types of data, collected for each individual, will be provided. This data will include anonymized individual participant demographic information and all outcome variables (cognitive task data, spectroscopy data).

IPD Sharing Time Frame

Beginning 9 months and ending 36 months following article publication.

IPD Sharing Access Criteria

The raw data will be made available by the researchers upon reasonable request by any qualified doctoral researcher (PhD, MD). They will be granted access by contacting the corresponding author/principal investigator (F. Gonzalez-Lima, utbrainproject@gmail.com).

It will be made available to qualified researchers whose proposed use of the data has been approved by an independent review committee (Institutional Review Board) identified for the purpose of individual participant data meta-analysis.

Proposals may be submitted up to 36 months following article publication. After 36 months, the data will be available in our University's shared network drive, but without investigator support other than deposited metadata.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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