NCT00109642

Brief Summary

This study will examine the role of a brain chemical called norepinephrine in thinking, decision-making, and emotional processing. After norepinephrine is released from a brain cell, it binds to another brain cell's receptor. Some of the receptors it binds to are called alpha-2 adrenergic receptors. This study will use medicines called yohimbine and guanfacine to look at the function of norepinephrine in the brain when it binds to the alpha-2 adrenergic receptors. Yohimbine increases norepinephrine's function and guanfacine decreases its function. Healthy volunteers between 20 and 50 years of age who do not have heart disease, high blood pressure, psychiatric illness, or other serious medical conditions and who are not allergic to lactose may be eligible for this study. Candidates are screened with a medical and psychiatric history, physical examination, neuropsychological testing, blood and urine tests and electrocardiogram. Women are screened with a urine pregnancy test. Participants are given a pill of yohimbine, guanfacine, or placebo and undergo the following tests and procedures:

  • Blood pressure and heart rate measurements: Blood pressure and heart rate are measured before the medication is taken and several times after.
  • Blood draws: Blood is drawn before the medicine is taken and 90 minutes after to measure levels of norepinephrine and the hormone cortisol.
  • Neurocognitive testing: Participants do neurocognitive tasks on the computer for up to 90 minutes. The tasks involve looking at pictures or words on a screen and responding according to instructions given.
  • Magnetic resonance imaging (MRI): Patients may undergo neurocognitive testing MRIs. This test uses a strong magnetic field and radio waves to show changes in brain activity. The subject lies on a table that slides into a narrow cylinder (the MRI scanner). Images of the brain are obtained while the subject performs the computer tasks.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
216

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Apr 2005

Longer than P75 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

April 26, 2005

Completed
3 days until next milestone

First Submitted

Initial submission to the registry

April 29, 2005

Completed
3 days until next milestone

First Posted

Study publicly available on registry

May 2, 2005

Completed
3.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 15, 2009

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 15, 2009

Completed
Last Updated

July 2, 2017

Status Verified

June 8, 2009

Enrollment Period

3.9 years

First QC Date

April 29, 2005

Last Update Submit

June 30, 2017

Conditions

Keywords

AmygdalaOrbitofrontal CortexYohimbineEmotionGuanfacineNorepinephrineHealthy Volunteer

Eligibility Criteria

Age20 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Age: Participants will be males and females, 20-50 years of age.
  • IQ: IQ, as measured by 4 subscales from the Wechsler Adult Intelligence Scale-Revised (WAIS-R), must be greater than 80.
  • Medication status: No current use of any psychotropic medication or benzodiazepine.

You may not qualify if:

  • Psychiatric History: Participants will be assessed using DSM-IV criteria via standardized psychiatric interviews conducted by trained examiners (SCID). All participants will be free of any current or past major affective disorder, psychotic disorder, substance dependence, anorexia, somatoform disorder, or anxiety disorders with the exception of specific phobias.
  • Severe acute and chronic medical illnesses (e.g. cardiac disease, diabetes, epilepsy).
  • CNS disease: Known history of brain abnormalities (e.g., neoplasms, subarachnoid cysts), cerebrovascular disease, infectious disease (e.g., abscess), other central nervous system disease, or history of head trauma which resulted in a persistent neurologic deficit or loss of consciousness greater than 3 minutes.
  • Currently on regular medication that would interfere with study results. This includes alpha and beta adrenergic medications, other anti-hypertensive medications, glucocorticoid and mineralocorticoid medications, and medications causing sedation or stimulation. For example, current use of tylenol or ibuprofen is permitted, while current use of benadryl or methylphenidate is not. Use of oral contraceptive pills is permitted.
  • Currently breast feeding or pregnant (as documented by pregnancy testing at screening or at days of the challenge studies).
  • Metal or electronic objects: Metal plates, certain types of dental braces, cardiac pacemakers, etc., that are sensitive to electromagnetic fields contraindicate MRI scans.
  • Claustrophobia: participants will be questioned about potential discomfort in being in an enclosed space, such as an MRI scanner.
  • Body weight - to reduce the likelihood of significant orthostasis from guanfacine, participants must weigh 60kg or greater. Those weighing less than 60 kg will be excluded.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

National Institutes of Health Clinical Center, 9000 Rockville Pike

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

  • Adolphs R. Neural systems for recognizing emotion. Curr Opin Neurobiol. 2002 Apr;12(2):169-77. doi: 10.1016/s0959-4388(02)00301-x.

    PMID: 12015233BACKGROUND
  • Arnsten AF. Adrenergic targets for the treatment of cognitive deficits in schizophrenia. Psychopharmacology (Berl). 2004 Jun;174(1):25-31. doi: 10.1007/s00213-003-1724-3. Epub 2003 Dec 19.

    PMID: 15205875BACKGROUND
  • Aron AR, Fletcher PC, Bullmore ET, Sahakian BJ, Robbins TW. Stop-signal inhibition disrupted by damage to right inferior frontal gyrus in humans. Nat Neurosci. 2003 Feb;6(2):115-6. doi: 10.1038/nn1003. No abstract available.

    PMID: 12536210BACKGROUND

MeSH Terms

Conditions

Antisocial Personality DisorderMental Disorders

Condition Hierarchy (Ancestors)

Personality Disorders

Study Design

Study Type
observational
Sponsor Type
NIH

Study Record Dates

First Submitted

April 29, 2005

First Posted

May 2, 2005

Study Start

April 26, 2005

Primary Completion

March 15, 2009

Study Completion

March 15, 2009

Last Updated

July 2, 2017

Record last verified: 2009-06-08

Locations