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Updated: Jul 28, 2026
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Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker
Published on: December 18, 2014
Dextroamphetamine modulates the response of the human amygdala
Ahmad R Hariri1, Venkata S Mattay, Alessandro Tessitore
1Clinical Brain Disorders Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA. hariria@intra.nimh.nih.gov
Summary
Amphetamine increases anxiety by affecting the amygdala, a brain region processing fear. This study shows dextroamphetamine enhances amygdala responses to fearful faces, linking drug effects to brain activity.
Area of Science:
- Neuroscience
- Psychopharmacology
- Neuroimaging
Background:
- Amphetamine, a monoaminergic agonist, influences human emotional behavior, including anxiety.
- Dopamine and other monoamines modulate amygdala activity, crucial for fear perception and response.
- Animal models suggest dopaminergic pathways influence the amygdala.
Purpose of the Study:
- To investigate if amphetamine's anxiogenic effects in humans are mediated by its influence on amygdala activity.
- To explore the neural mechanisms underlying amphetamine-induced anxiety.
Main Methods:
- A double-blind, placebo-controlled study design.
- Functional magnetic resonance imaging (fMRI) to measure brain activity.
- Assessment of amygdala response during the processing of emotional facial expressions (angry and fearful).
Main Results:
- Dextroamphetamine significantly potentiated the amygdala's response to angry and fearful facial expressions.
- fMRI data revealed increased amygdala activation under amphetamine compared to placebo.
- This provides direct evidence of amphetamine's effect on a key fear-processing brain region.
Conclusions:
- The study provides the first direct neural evidence linking amphetamine's anxiogenic effects to amygdala potentiation in humans.
- Findings support the role of dopaminergic activation of the amygdala in mediating drug-induced anxiety.
- Results align with and extend findings from animal models.
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