Parental Warmth, Stressful Life Events, and Impulsivity: A Gene-Environment-Wide Interaction Study

Objective: Impulsivity is influenced by genetic, neural, and environmental factors, but no study has examined how these factors work together to generate individual differences in impulsivity. The present study aimed to define the functional network that subserves impulsivity and test its relations with the gene-environment interactions found in the gene-environment-wide interaction study. Method: This study used a sample of healthy Chinese college students (N = 1,145) to identify gene-environment interactive effects on impulsivity, then defined the functional brain network related to impulsivity in an independent sample (N = 483), and explored the gene-brain associations using polygenic risk score. Results: The present study found that 14 genes showed significant interactive effects with parental warmth (a protective environmental factor) and that six genes showed significant interactive effects with stressful life events (a risk environmental factor). The polygenic risk score for parental warmth was significantly correlated with functional connectivity especially the left middle frontal gyrus (MFG)-left inferior occipital and left MFG-left superior frontal gyrus functional connectivity, while the polygenic risk score for more stressful life events was significantly correlated with functional connectivity of left dorsal medial prefrontal cortex (DMPFC) to other regions. These associations were stronger in more adverse environments (i.e., low parental warmth or high stressful life events). Conclusions: This was the first gene-environment-wide interaction study of impulsivity. Future studies should replicate our results and explore the underlying mechanisms of these interactions. Key Points Question: How do genetic, neural, and environmental factors work together to generate individual differences in impulsivity? Findings: Protective (parental warmth) and risk (stressful life events) environmental factors can modulate distinct genetic effects on impulsivity through different neural mechanisms. Importance: Life adversity (like stress) needs to be taken into consideration to reduce impulsivity. Next Steps: Future studies should replicate our results and explore the underlying mechanisms of these interactions.