Psychopharmacology of Fear-Potentiated Startle in Humans
Completed
Conditions studied: Healthy
In brief
The purpose of this study is to understand the effects of the drug alprazolam (Xanax ) on anxiety. To understand the effect of anxiety-relieving drugs on fear and anxiety, researchers often have participants anticipate unpleasant stimuli. Anticipating unpleasant stimuli increases or potentiates a simple reflex called the startle reflex. The so-called fear-potentiated startle reflex (FPS) effect may be blocked or reduced by anxiety-relieving drugs. Evidence suggests that the FPS can be mediated by two mechanisms that regulate the phasic- and sustained enhancement of startle. This study will elicit phasic and sustained FPS in participants by having them anticipate moderately painful stimuli that are administered predictably and unpredictably. The main goal of this study is to assess the affect of alprazolam on the phasic and sustained enhancement of startle. This study comprises two pilot experiments and a main study. Participants in the study will be screened with a psychiatric history, physical examination, electrocardiogram (EKG), and blood and urine tests. Participants will four testing sessions separated by 5 to 10 days. At each session, participants will be given one of two doses of alprazolam, diphenhydramine, or placebo (an inactive pill). Questionnaires and other tests will be performed.
Key facts
- Study ID
- NCT00044096
- Run by
- National Institute of Mental Health (NIMH)
- People needed
- 225
- Starts
- 2002-08-15
- Expected to finish
- 2013-09-17
- Last updated by the study team
- 2018-07-05
Who can join
Age: 18 and older, up to 45. Sex: any. Healthy volunteers: accepted.
You may not qualify if…
- Any significant medical or neurological problems (e.g. cardiovascular illness, respiratory illness, neurologic illness, seizure, etc.)
- Adverse reactions to cortisol (cortisol study only)
- Adverse reactions to benzodiazepines or antihistamines (alprazolam study only)
- History of angioedema
- Osteoporosis (Hydrocortisone study only)
- High or low blood pressure
- History of fainting
- First degree relative with history of mania, schizophrenia, or other psychoses
- A history of mania, schizophrenia, or other psychoses
- Current migraine
- Use of herbal medicines or dietary supplements with psychoactive properties (citalopram study only)
- Any current psychiatric disorders
- Past alcohol/drug dependence and alcohol/drug abuse in past one year
- Current use of psychotropic medication
- Impaired hearing
- Pregnancy
- Breast-feeding or currently taking contraceptive hormones (oxytocin/vasopressin study only)
- Positive results of beta-human chorionic gonadotropin testing (females only)
- Neurological syndrome of the wrist (e.g., carpal tunnel syndrome)
Where it is running
- National Institutes of Health Clinical Center, 9000 Rockville Pike — Bethesda, Maryland, United States
Full record on ClinicalTrials.gov
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