Genetic influences on externalizing psychopathology overlap with cognitive functioning and show developmental...

Area of Science:

• Psychiatric genetics
• Developmental psychology
• Cognitive neuroscience

Background:

• Genetic underpinnings of early psychopathology and their relationship with cognition remain unclear.
• Developmental changes in genetic influences on psychopathology require further investigation.

Purpose of the Study:

• To investigate genetic influences on psychopathology factors in youth.
• To examine the genetic overlap between psychopathology and cognitive abilities.
• To determine if genetic influences on psychopathology vary across development.

Main Methods:

• Utilized data from the Philadelphia Neurodevelopmental Cohort (N=9,421, ages 8-21).
• Generated psychopathology factors using a bifactor model from psychiatric interview data.
• Conducted genetic analyses (heritability, genetic correlations) on European American participants (N=4,662).
• Performed Gene × Age analyses to assess developmental variation in genetic influences.

Main Results:

• Externalizing behaviors were heritable (h²=0.46), unlike other factors.
• Externalizing showed significant genetic correlations with various cognitive functions, including reasoning, memory, and general cognitive ability.
• Gene × Age analyses indicated decreasing genetic variance and increasing environmental variance for externalizing behaviors with age.

Conclusions:

• Cognitive impairments may serve as an endophenotype for externalizing psychopathology, aiding in understanding its pathophysiology.
• Reduced genetic variance in older individuals suggests that gene discovery for externalizing behaviors is more promising in childhood.