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.
26 studies on the registry are indexed under Arachnophobia; 2 are open to participants now.
This study's planned enrollment of 88 is above the median of 60 across 26 interventional studies indexed under Arachnophobia.
Browse Arachnophobia studies →Walter Reed Army Institute of Research (WRAIR) is the lead sponsor of 20 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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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Studies of the drugs tested here: Propranolol · Hydrocortisone
Walter Reed Army Institute of Research (WRAIR)