NCT07079839 · The University of Texas Health Science Center, Houston
A Neurosensory Account of Anxiety and Stress (Study 2)
What this study is about
This study will take a basic neuroscience approach to investigate pathological mechanisms underlying PTSD.
View original scientific description
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.
Interventions
DEVICE
Transcranial Alternating Current Stimulation (tACS)
A weak electrical current will be passed through the scalp over targeted cortical regions via a transcranial electrical stimulation system (Soterix Medical, Inc), for a span of 10 to 40 minutes at a time. Participants will receive a 2 milliamp (mA) sinusoidal current oscillating at individual participants' baseline peak alpha frequencies (PAF; 7-13 Hz), which will be determined by a 3-min resting state EEG recording during the setup. Current intensities will be modified to address individual participants' subjective reports of discomfort, with a maximum intensity of 2 mA. Stimulation electrodes will be placed within an EEG cap fitted over the participant's head.
DEVICE
Sham for Transcranial Alternating Current Stimulation (tACS)
Stimulation electrodes will be placed on the scalp, but no current will be passed. Stimulation electrodes will be placed within an EEG cap fitted over the participant's head.
DEVICE
Transcranial Random Noise stimulation (tRNS)
A weak electrical currents will be passed through the scalp over targeted cortical regions via a transcranial electrical stimulation system (Soterix Medical, Inc), for a span of 10 to 40 minutes at a time. Participants will receive a 2 mA sinusoidal current oscillating at random frequency (1-200 Hz). Current intensities will be modified to address individual participants' subjective reports of discomfort, with a maximum intensity of 2 mA. Stimulation electrodes will be placed within an EEG cap fitted over the participant's head.
Primary outcome measures
Change in neural oscillatory activity as assessed by electroencephalogram (EEG) alpha power change
Time frame: 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
Time frame: baseline (pre-stimulation); immediately post-stimulation (about 10 to 40 minutes after start of stimulation)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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 Diagnostic and Statistical Manual of Mental Disorders (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 magnetic resonance (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.
Where
- Houston, Texas
Collaborators
National Institute of Mental Health (NIMH)
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 12, 2025 · Source of record for eligibility and locations