A Phase 4 interventional study of Propranolol and Hydrocortisone in Fear of Spiders and Acute Stress Reaction, sponsored by Walter Reed Army Institute of Research (WRAIR). Recruiting at 1 site in United States. Open to participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-05-13.
Sponsored by Walter Reed Army Institute of Research (WRAIR) · Phase 4, Interventional, and Prevention
This clinical trial aims to evaluate the nature and duration of effects of three FDA-approved medications (propranolol and hydrocortisone) on military-relevant cognitive, emotional, and motor performance following an exposure to a stressful situation (i.e., exposure to a tarantula) in physically healthy adult volunteers (aged 18 - 40) with fear of spiders to help the future development of medications for treating Acute Stress Reactions.
The main questions this study aims to answer are:
Will placebo treatment (oral placebo) result in significant decrements in Psychomotor Vigilance Task (PVT) performance compared to propranolol treatment?
Will placebo treatment [intramuscular (IM) placebo] result in significant decrements in PVT performance compared to hydrocortisone treatment?
Participants will receive one of five study medications (oral propranolol, oral placebo, IM hydrocortisone, or IM placebo) after a brief exposure to a tarantula. Participants will complete cognitive and simple motor tasks and psychological assessments before and after the study medication administration.
Exclusion Criteria:
Drug: Propranolol
Drug: Placebo (oral)
Drug: Hydrocortisone
Drug: Placebo (IM)
An administration of a 40-mg propranolol capsule immediately after tarantula exposure
An intramuscular administration of 62.5 mg/1 ml of hydrocortisone immediately after tarantula exposure
An administration of a placebo capsule after tarantula exposure
An intramuscular administration of 1 ml of saline immediately after tarantula exposure
Psychomotor Vigilance Task
Measure of cognitive performance. Reaction time (millisecond)
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Go/No-Go task
Measure of cognitive performance.
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Matching to Sample task
Measure of cognitive performance
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Simple Reaction Time task
Measure of cognitive performance.
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
The Automated Neuropsychological Assessment Metrics (ANAM) Mood Scale
Measure of mood.
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
WRAIR Mood Battery
A short battery of measures of various aspects of mood.
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Heart rate
Continuous measure of heart rate.
Time frame: Before, during, and after behavioral approach task. Approximately 1 hour.
Biosway
Measure of motor performance
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Triple Hop Test
Measure of motor performance.
Time frame: Baseline and post-treatment time points within approximately 7 hours following the study medication administration.
Drug Effects Questionnaire
Measure of subjective response to a substance.
Time frame: Multiple time points within approximately 7 hours following the study medication administration.
Subjective Fear Scale
Subjective measure of fear. A 0 - 100 numerical scale.
Time frame: Baseline, during the behavioral approach test, and time points within approximately 7 hours after the study medication administration.
Subjective Anxiety Scale
Subjective measure of anxiety. A 0 - 100 numerical scale.
Time frame: Baseline, during the behavioral approach test, and time points within approximately 7 hours after the study medication administration.
Subjective Stress Scale
Subjective measure of stress. A 0 - 100 numerical scale.
Time frame: Baseline, during the behavioral approach test, and time points within approximately 7 hours after the study medication administration.
Symptom checklist
Checklist to capture adverse drug reactions.
Time frame: Baseline, pre-medication administration, and time points within approximately 8 hours after the medication administration.
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Arachnophobia
Walter Reed Army Institute of Research (WRAIR)