Related Experiment Video
Updated: Jul 9, 2026

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat
Published on: September 12, 2014
Don't panic. A guide to tryptophan depletion with disorder-specific anxiety provocation
S D Hood1, C J Bell2, S V Argyropoulos3
1School of Psychiatry & Clinical Neurosciences (M521), University of Western Australia, Perth, WA, Australia sean.hood@uwa.edu.au.
Abstract:
The 2002 paper "Does 5-HT restrain panic? A tryptophan depletion study in panic disorder patients recovered on paroxetine" by Bell and colleagues - reprinted in this issue of the Journal - reports on a study undertaken in the halcyon days of David Nutt's Psychopharmacology Unit at the University of Bristol, England. In this invited commentary authors of the original work discuss the impact of this paper on the field of acute tryptophan depletion research (especially in the field of clinical anxiety disorders) and the development of disorder-specific anxiogenic provocations over the past decade.
Related Concept Videos
Anxiety: Overview
Individuals with anxiety often experience a range of physical and emotional symptoms, including sweating, trembling, tachycardia, and disturbances in sleep patterns. These symptoms vary in intensity and frequency but are generally disruptive and distressing.
Anxiolytic Drugs: Overview
Primary Types of Anxiolytic Drugs
1. Benzodiazepines:
Benzodiazepines bind to the GABA-A receptor in the brain, enhancing GABA's interaction. This action reduces neurotransmission, effectively blocking anxiety-associated limbic circuitry.
Anxiolytic Drugs: Benzodiazepines and Buspirone
Generalized Anxiety Disorder
Panic Disorder
Behavior Therapy
Exposure therapy is a cornerstone of behavioral treatment for anxiety disorders. It involves systematic exposure to feared stimuli, either in real...

