Fenfluramine challenge in anxious children.

Area of Science:

• Neuroscience
• Child Psychiatry
• Pharmacology

Background:

• Childhood anxiety disorders are prevalent and require accurate diagnostic tools.
• Serotonergic pathways are implicated in anxiety and obsessive-compulsive disorder (OCD).
• Pharmacological challenges can probe neurobiological differences in psychiatric conditions.

Purpose of the Study:

• To investigate if serotonergic challenge using fenfluramine can differentiate childhood anxiety disorders from healthy controls.
• To examine neurohormonal and mood responses to fenfluramine in children with anxiety.
• To identify specific patterns distinguishing obsessive-compulsive disorder (OCD) within anxiety diagnoses.

Main Methods:

• A cohort of 24 children diagnosed with anxiety disorders (DSM-IIIR) and 14 healthy controls (ages 7-14) participated.
• Subjects received an oral dose of racemic fenfluramine (1 mg/kg).
• Cardiovascular, neurohormonal (prolactin), and mood parameters were assessed over five hours.

Main Results:

• Healthy controls showed increased subjective anxiety and systolic blood pressure post-fenfluramine compared to anxious subjects.
• An exaggerated prolactin response to fenfluramine differentiated a subset of children with obsessive-compulsive disorder (OCD) from other anxiety diagnoses and controls.
• Fenfluramine challenge was well-tolerated and did not induce panic symptoms.

Conclusions:

• Fenfluramine challenge can differentiate anxious children from healthy controls based on anxiety ratings and blood pressure.
• Elevated prolactin response to fenfluramine is a potential biomarker for childhood obsessive-compulsive disorder (OCD).
• Observed differences in prolactin response may suggest developmental changes in serotonin pathways for OCD.