Neuroticism has societal, mental and physical health relevance, with an etiology involving genetic predisposition, psychological influence, and their interaction.

To understand whether the association between polygenic risk score for neuroticism (PRS-N) and neuroticism is moderated by affective well-being.

Data were derived from TwinssCan, a general population twin cohort (age range=15-35 years, 478 monozygotic twins). Self-report questionnaires were used to measure well-being and neuroticism. PRS-N was trained from the Genetics of Personality Consortium (GPC) and United Kingdom Biobank (UKB). Multilevel mixed-effects models were used to test baseline and changes in well-being and neuroticism.

Baseline wellbeing and neuroticism were associated (β=-1.35, p<0.001). PRSs-N were associated with baseline neuroticism (lowest p-value: 0.008 in GPC, 0.01 in UKB). In interaction models (PRS x wellbeing), GPC PRS-N (β=0.38, p=0.04) and UKB PRS-N (β=0.81, p<0.001) had significant interactions.

PRSs-N were associated with changes in neuroticism (lowest p-value: 0.03 in GPC, 0.3 in UKB). Furthermore, changes in wellbeing and neuroticism were associated (β =-0.66, p<0.001). In interaction models (PRS x change in wellbeing), only UKB PRS-N had a significant interaction (β=0.80, p<0.001).

Interaction between polygenic risk, wellbeing and neuroticism, were observed regarding baselines measures and change over time. Depending on the analysis step, the direction of the effect changed.

None Declared