Polygenic Risk for Externalizing Psychopathology and Executive Dysfunction in Trauma-Exposed Veterans

Area of Science:

• Behavioral Genetics
• Psychiatric Genetics
• Neuroscience

Background:

• Antisocial behavior and disinhibited traits often co-occur, indicating a shared genetic basis within an externalizing spectrum.
• Understanding the molecular genetic underpinnings of this spectrum is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the polygenic associations with externalizing psychopathology, impulsive traits, and cognitive functions.
• To examine the moderating role of polygenic risk for externalizing in the context of trauma exposure.

Main Methods:

• Utilized polygenic risk scores to assess genetic liability for externalizing psychopathology.
• Analyzed data from two independent samples of primarily military veterans (N=731).
• Tested for gene-by-environment interactions between polygenic risk and trauma exposure.

Main Results:

• Polygenic risk positively predicted externalizing psychopathology symptoms.
• Higher polygenic risk was associated with poorer performance on inhibitory control tasks.
• Gene-environment interactions showed trauma exposure predicting increased impulsivity and reduced working memory capacity, but only under high genetic liability.
• No significant associations were found between polygenic risk and internalizing psychopathology or episodic memory.

Conclusions:

• This study provides the first independent replication of polygenic scores as a measure of genetic predisposition for externalizing behaviors.
• Executive dysfunction appears to be a heritable vulnerability associated with externalizing psychopathology.
• Genetic liability and environmental factors like trauma interact to influence externalizing phenotypes.