BACKGROUND: Uncertainties remain about the role of serotonin in the aetiology and treatment of panic disorder.
AIMS: To investigate the effect of reducing brain serotonin function on anxiety at rest, and following 5% CO2 provocation in normal controls and patients with panic disorder.
METHOD: Twenty drug-free patients with DSM-III-R panic disorder and 19 controls received a tryptophan-free amino acid drink on one occasion and a control drink on the other in a double-blind, balanced protocol. 5% CO2 was given as a panic challenge after 270 minutes.
RESULTS: Plasma tryptophan fell by more than 80% both patients and controls after the tryptophan-free drink. Tryptophan depletion did not alter resting anxiety. In patients alone, tryptophan depletion caused a greater anxiogenic response and an increased rate of panic attacks (9 v. 2, P < 0.05) after 5% CO2 challenge. No normal volunteers panicked.
CONCLUSIONS: Serotonin may directly modulate panic anxiety in patients with panic disorder. This may underlie the efficacy of serotonergic antidepressants in treating panic disorder.
|Number of pages||7|
|Journal||The British journal of psychiatry : the journal of mental science|
|Publication status||Published - Feb 2000|
- Analysis of Variance
- Carbon Dioxide
- Case-Control Studies
- Middle Aged
- Panic Disorder
- Psychological Tests
- Time Factors
- Clinical Trial
- Journal Article
- Randomized Controlled Trial
- Research Support, Non-U.S. Gov't