Related Experiment Video
Updated: Sep 25, 2026

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat
Published on: September 12, 2014
[Appearance of anxiety after intake of a placebo]
Abstract:
In 45 of 73 patients (organic brain syndromes of complex genesis, schizophrenia, manic phase of manic-depressive psychosis, alcoholism), intake of placebo one week before discharge induced anxiety accompanied by dryness of the mouth, enhanced perspiration and increase of tremor. Anxiety/disappeared after verbal information that the action of this drug is exhausted 1 hour after its intake. Peculiarity of this observation consists in the fact that all placebo responders (61.6% of patients) appeared to be negative, i.e. they had no positive placebo responses. According to the reported data, the negative placebo responses are observed in 10-20% of patients. Anxiety is considered as a symptom provoked by placebo in patients who are in the "neurotic" phase following the cessation of psychotic symptomatology.
Related Concept Videos
The Placebo Effect
Blind Procedures
Blinding
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
Classical Conditioning in Daily Life
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...

