Association between neuroticism and cosmetic mammoplasty: Results from a bidirectional Mendelian randomization study.

Observational studies have suggested associations between neuroticism and the tendency to undergo cosmetic mammoplasty, but their causal relationships remain unclear. Our study aimed to assess the causal associations between neuroticism and cosmetic mammoplasty using a bidirectional 2-sample Mendelian randomization method. Genetic associations with neuroticism (n = 329,821) and cosmetic mammoplasty (n = 462,933) were identified in genome-wide association studies of European ancestry. The inverse-variance weighted (IVW) was designated as the primary model for data analysis, supplemented with weighted median, Mendelian randomization-Egger, weighted mode, and simple mode method. Genetically determined neuroticism was positively associated with the incidence of cosmetic mammoplasty (IVW odds ratio = 1.002, P = .019). Reversely, predisposition to cosmetic mammoplasty genetically increased the risk of neuroticism (IVW odds ratio = 21.041, P = 2.05 × 10-3). Our results suggested a bidirectional causal relationship between neuroticism and cosmetic mammoplasty. These findings may highlight the potential influence of psychological factors on patients undergoing cosmetic surgery.