A Neurosensory Account of Anxiety and Stress (Study 1)

Not Applicable

Recruiting

• Conditions: Posttraumatic Stress Disorder (PTSD); Intrinsic and Novelty-related Sensory Cortical (SC) Disinhibition

• Registration Number: NCT05895006
• Lead Sponsor: The University of Texas Health Science Center, Houston

Brief Summary

This study will take a basic neuroscience approach to investigate pathological mechanisms underlying PTSD. Additionally, the study aims to identify how Transcranial Alternating Current Stimulation (tACS) brain stimulation can modulate and correct neural networks and related emotions of anxious arousal and hypervigilance, with the goal of assessing tACS brain stimulation technology as a novel intervention for symptoms of anxiety.

Detailed Description

This study includes experiments 1a \& 1b to address Aims 1 and -- Intrinsic and Novelty-related Sensory Cortical (SC) Disinhibition and Sensory-Prefrontal-cortex-Amygdala (SPA) pathology in PTSD. The goal of this study is to develop and test a novel pathophysiology of PTSD by integrating sensory cortical (SC) and amygdala-prefrontal cortex (PFC) dysfunctions into a tripartite Sensory-Prefrontal-Cortex-Amygdala (SPA) model.

The investigators will recruit 80 healthy subjects and 80 patients with PTSD in a randomized, double-blind, controlled design, where they be randomly assigned to 1) Transcranial Alternating Current Stimulation (tACS) at individual alpha peak frequency (active condition); 2) sham control tACS; or 3) active control, which will be transcranial random noise stimulation (tRNS) (random frequency 1-200 Hz). During tACS/sham tACS/tRNS stimulation, stimulation electrodes will be placed inside the holders of an EEG cap attached to the head of the participant. Simultaneous EEG- fMRI recordings during the resting state (in experiment 1a) and during a novelty task (in experiment 1b) will be acquired before and after tACS/tRNS stimulation.

Study Timeline

• Study Start: 2022-04-05
• Study First Submitted: 2023-04-21
• Study First Submitted QC: 2023-05-30
• Study First Posted: 2023-06-08
• Status Verified: 2025-09
• Last Update Submitted: 2025-09-05
• Last Update Posted: 2025-09-12
• Primary Completion: 2026-12-31
• Study Completion: 2026-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 160

Inclusion Criteria

• Right-handed
• With normal or corrected-to-normal vision and normal olfaction
• Between the ages of 18 and 50 years
• Meeting the tACS screening criteria (see List I below; e.g., lack of a serious head injury or loss of consciousness)
• Patients: Diagnosis of PTSD
• Patients: If taking psychotropic medications, medication stability in the past 2 months
• If having mild substance use disorder (for patients) or occasional substance use, abstention from use 48 hours before the experiment.

Exclusion Criteria

• A history of diagnosis for a major medical illness (e.g., cancer, metabolic syndrome, cardiovascular disease, inflammatory disorders) or a neurological disorder (e.g., seizure, stroke, Parkinson's disease).
• Patients: Concurrent Axis I diagnosis (depression, anxiety, and mild substance use disorder are allowed given their high comorbidity with PTSD).
• Healthy controls: A history of diagnosis for a DSM-5 Axis I disorder or current use of psychoactive medications.
• Severe psychiatric instability or severe situational life crises, including evidence of being actively suicidal or homicidal, or any behavior that poses an immediate danger to self or others.
• History of head trauma with unconsciousness (> 5 minutes)
• Report that they regularly drink 3 or more alcoholic beverages a day.
• Report that they are unable to abstain from substance use (including alcohol, nicotine, cannabis, amphetamines, narcotics, solvents, cocaine, hallucinogens, tranquilizers, barbiturates, etc.) or sleep medication for 48 hours before being scanned.
• Are on calcium channel blockers (e.g., verapamil, nifedipine) or alpha-blockers (e.g., prazosin, terazosin) and are unable to stop these medications for a 48-hour period prior to scanning (to exclude the impact of these medications on the interpretation of fMRI/EEG).
• Failed Urine Drug Screening Test: A rapid urine screening test that utilizes monoclonal antibodies to detect elevated levels of specific drugs (including alcohol, amphetamines, benzodiazepines, barbiturates, cocaine, marijuana, opiates, etc.) in urine (iCup)
• Pregnancy based on urine test. The safety of MR systems has not been established for fetuses
• Having electrically, magnetically, or mechanically activated implants (e.g., cardiac pacemakers), because the electromagnetic fields produced by the MR system may interfere with the operation of these devices.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change in neural oscillatory activity as assessed by electroencephalogram (EEG) alpha power change	baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)
Change in cortical activity as assessed by functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) signal change	baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)

Secondary Outcome Measures

Name	Time	Method
Change in salience detection and vigilance behavior as assessed by percent accuracy on an oddball detection task	baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)
Change in salience detection and vigilance behavior as assessed by reaction time in milliseconds (ms) on an oddball detection task	baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)
Change in salience detection and vigilance behavior as assessed by skin conductance measured in microsiemens (μS)	baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)

Trial Locations

Locations (1)

The University of Texas Health Science Center at Houston; 🇺🇸 Houston, Texas, United States