Expectation of Unpleasant Events in Anxiety Disorders
Condition: Anxiety Disorders
MeSH terms: Anxiety Disorders
Study type: Interventional

Summary: 
      Fear and anxiety are normal responses to a threat. However, anxiety is considered abnormal
      when the response to the threat is excessive or inappropriate. This study will examine
      changes in the body and brain that occur during unpleasant learning experiences in healthy
      volunteers with high, moderate, and low levels of anxiety.

      A high degree of generalized anxiety is a component of many anxiety disorders and is regarded
      as a marker of vulnerability for these disorders. People with anxiety disorders and
      individuals with high degrees of anxiety have inappropriate expectations of unpleasant
      events. This study will investigate the development of expecting unpleasant events in healthy
      volunteers with varying degrees of anxiety using aversive conditioning models. A later phase
      of the study will enroll participants with anxiety disorders and compare their responses to
      those of healthy volunteers.

      Patients who meet criteria for an anxiety disorder, and healthy volunteers who have no
      history of psychiatric or major medical illness will be enrolled in this study. Volunteers
      will come to the NIH Clinical Center three times for outpatient testing....
    

Detailed description: 
      High-generalized anxiety is a concomitant of many anxiety disorders and is often regarded as
      a vulnerability marker for these disorders. One characteristic of patients with anxiety
      disorders and high trait-anxious individuals is inappropriate expectancies of aversive
      events. The overall aim of the present protocol is to investigate mechanisms that may promote
      the development of these aversive expectancies using expectancy-based, associative-learning
      models.

      During aversive conditioning in which a phasic explicit-cue (e.g., a light) is repeatedly
      associated with an aversive unconditioned-stimulus (e.g., a shock), the organism develops
      fear to the explicit cue as well as to the environmental context in which the experiment took
      place. We have obtained preliminary evidence suggesting that contextual fear represents
      aspects of aversive states that are central to anxiety disorders. In this protocol, we seek
      further evidence for the relevance of contextual fear to mood anxiety disorders.

      One important determinant of contextual fear in both humans and animals is predictability:
      contextual fear increases when aversive events (e.g., electric shock) are unpredictable, as
      opposed to when they are predictable. The present protocol will examine the role of
      predictability of aversive states and of conditioning on threat appraisal in individuals with
      mood and anxiety disorders.

      A second aim is to examine the interaction between experimentally-induced anxiety and
      cognitive processes, more specifically working memory, in mood and anxiety disorders.
    

Intervention name(s): Threat of shock
Intervention type(s): Device
Intervention description(s): During threat, a participant could receive a shock. During safe, a participant could not receive as shock. Participants selected their highest tolerable level of shock.
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Anxiety Disorder; Psychophysiology; Shock Threat; Context Conditioning; Agoraphobia; Panic Disorder; Generalized Anxiety Disorder; GAD; Healthy Volunteer; HV