Polygenic Score of Subjective Well-Being Is Associated with the Brain Morphology in Superior Temporal Gyrus and Insula.

Subjective well-being (SWB) is closely related to our physical and mental health. Existing studies show that neural or genetic basis underpins individual difference in SWB. Moreover, researchers have found high enrichment of SWB-related mutations in the central nervous system, but the relationship between the genetic architecture of SWB and brain morphology has not been explored. Considering the polygenic nature of SWB, in this study, we aim to establish a measure of additive genetic effect on SWB and explore its relationship to the brain anatomical structure. Based on the results of genome-wide association study (GWAS) on SWB, the polygenic scores (PGSs) of SWB at eight different thresholds were calculated in a large Chinese sample (N = 585). Then, we analyzed the associations between the PGSs of SWB and cortical thickness (CT) or gray matter volume (GMV) measured from 3.0-T structural imaging data. In whole-brain analyses, we found that a higher PGS was significantly associated with increased CT in the right superior temporal gyrus (STG) and GMV in the right insula, both of which are involved in social cognition and emotional processing. More importantly, these findings were repeatable at some different thresholds. The results may suggest that the brain morphology of right STG and insula is partly regulated by SWB-related genetic factors.