Impulsiveness and the prolactin response to d-fenfluramine

Area of Science:

• Neuroscience
• Psychiatry
• Pharmacology

Background:

• Serotonin function abnormalities are linked to aggression and impulsivity in clinical populations.
• It remains unclear if serotonin influences trait impulsiveness in the general population or only extreme groups.

Purpose of the Study:

• To investigate the relationship between serotonin function and trait impulsiveness in healthy adults.
• To determine if reduced serotonin function is specific to extreme behavioral groups or also present in the general population.

Main Methods:

• Assessed prolactin response to d-fenfluramine in healthy volunteers with high and low impulsiveness scores.
• Utilized the 17 impulsiveness scale, State Trait Anger Expression Inventory (STAngXI), and Tridimensional Personality Questionnaire (TPQ).
• Measured plasma cortisol and fenfluramine/norfenfluramine levels for covariate analysis.

Main Results:

• Individuals with high trait impulsiveness exhibited a reduced area under the curve for prolactin (PRL) response compared to the low impulsive group.
• This reduction in PRL response remained significant after adjusting for baseline prolactin, cortisol, and drug levels.
• No significant association was found between impulsiveness, harm avoidance (TPQ), or trait anger (STAngXI) and the prolactin rise.

Conclusions:

• Findings support the hypothesis that diminished serotonin function is associated with higher trait impulsiveness.
• This association appears to extend to the general population and is not limited to behaviorally extreme individuals.