A Neurosensory Account of Anxiety and Stress

Launched by THE UNIVERSITY OF TEXAS HEALTH SCIENCE CENTER, HOUSTON · Jul 18, 2025

Keywords

ClinConnect Summary

This clinical trial is exploring how certain brain processes may contribute to PTSD (Posttraumatic Stress Disorder), especially feelings of anxiety and being overly alert to danger. The study is testing a special type of brain stimulation called Transcranial Alternating Current Stimulation (tACS) to see if it can help adjust brain activity and reduce symptoms like anxious arousal and hypervigilance. The goal is to find out if this brain stimulation could become a new way to help people with anxiety related to PTSD.

To take part, you need to be between 18 and 50 years old, right-handed, have normal or corrected vision and smell, and have a diagnosis of PTSD. If you’re on medications for your mental health, these need to be stable for at least two months. You should not have serious medical or neurological conditions, and you must be able to avoid using substances like alcohol or drugs for two days before the study sessions. The study involves brain scans and brain stimulation sessions, and pregnant women or people with certain medical implants cannot participate. This study is currently recruiting participants who meet these criteria.

Gender

ALL

Eligibility criteria

• 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.