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Effects of Arousal and Stress in Anxiety

This study is currently recruiting participants. (see Contacts and Locations)
Verified February 6, 2017 by National Institutes of Health Clinical Center (CC)
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Mental Health (NIMH) ) Identifier:
First received: November 10, 2001
Last updated: April 20, 2017
Last verified: February 6, 2017

This study has several parts. One part will examine the influence of factors such as personality and past experience on reactions to unpleasant stimuli. Others will examine the effect of personality and emotional and attentional states on learning and memory.

When confronted with fearful or unpleasant events, people can develop fear of specific cues that were associated with these events as well as to the environmental context in which the events occurred via a process called classical conditioning. Classical conditioning has been used to model anxiety disorders, but the relationship between stress and anxiety and conditioned responses remains unclear. This study will examine the relationship between cued conditioning and context conditioning . This study will also explore the acquisition and retention of different types of motor, emotional, and cognitive associative processes during various tasks that range from mildly arousing to stressful.

Anxiety Disorder

Study Type: Observational
Official Title: Effects of Arousal and Stress on Classical Conditioning

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 1427
Study Start Date: June 26, 2001
Detailed Description:

Objective: Fear and anxiety are adaptive responses to different types of threats. Fear is a short-duration response evoked by explicit threat cues. Fear can best be studied using Pavlovian fear conditioning. Studies 1 and 2 examine learning processes underlying fear conditioning as well as the influence of cognitive and affective processes on these learning processes. Anxiety is a more sustained state of apprehension evoked by unpredictable threat. Study 2 examines the interactions between anxiety induced experimentally and cognitive processes. Specifically, we seek to 1) characterize the effect of anxiety on key cognitive processes including working memory, attention control, conflict, and learning and memory. 2) examine the extent to which performance of cognitive tasks distract from anxiety, and 3) how physical exertion influences anxiety and its effects on cognition. Study 3 examines the effects of memory

retrieval on extinction.

Study population: This more-than-minimal-risk protocol will test medically and psychiatrically healthy volunteers aged 18-50. Pregnant or nursing women will be excluded.

Method: Fear and anxiety will be measured using the startle reflex to brief and loud sounds. Fear conditioning will be assessed using shock as unconditioned stimulus. Cognitive performance will be examined during periods of unpredictable shock anticipation or prior to giving a speech.

Outcome measures: The study will include cognitive performance and measure of aversive states, primarily the startle reflex.


Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
  • Males and females
  • Age 18-50


  • Pregnancy
  • Any current ongoing medical illness
  • Current Axis I disorders
  • Past significant psychiatric disorders (e.g., psychotic disorders) according to DSM-IV
  • Current alcohol or substance abuse according to DSM-IV criteria
  • History of alcohol or substance dependence based on DSM-IV criteria within 6 months prior to screening
  • Current psychotropic medication use
  • Current or past organic central nervous system disorders, including but not limited to seizure disorder or neurological symptoms of the wrist and arms (e.g., carpal tunnel syndrome). The latter exclusion is for shock studies only.
  • Negative urine toxicology screen
  • For exercise substudy:

    • History of exercise intolerance
    • History of heart disease
    • History of pulmonary disease, other than controlled, non-exercise-induced asthma
    • History of uncontrolled diabetes
    • Resting heart rate > 90 BPM
    • Resting systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg
    • Peripheral condition making completion of the exercise protocol impossible, such as severe osteoarthritis or chronic pain
    • Clinically significant abnormal EKG as determined by MD or DNP
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00026559

Contact: Christian Grillon, Ph.D. (301) 594-2894

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike Recruiting
Bethesda, Maryland, United States, 20892
Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL)    800-411-1222 ext TTY8664111010   
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
Principal Investigator: Christian Grillon, Ph.D. National Institute of Mental Health (NIMH)
  More Information

Additional Information:
Responsible Party: National Institute of Mental Health (NIMH) Identifier: NCT00026559     History of Changes
Other Study ID Numbers: 010185
Study First Received: November 10, 2001
Last Updated: April 20, 2017

Keywords provided by National Institutes of Health Clinical Center (CC):
Classical Conditioning
Fear Conditioning
Normal Volunteers
Healthy Volunteer
Normal Control

Additional relevant MeSH terms:
Anxiety Disorders
Mental Disorders processed this record on April 28, 2017