Are Neuroticism, Depressive Rumination, and Anger Rumination Genetically Distinct?

Anger and depressive rumination – patterns of repetitive, self-focused thought in response to either anger or sadness – are transdiagnostic risk factors of psychopathology. Previous research has identified these two... [ view full abstract ]

Anger and depressive rumination – patterns of repetitive, self-focused thought in response to either anger or sadness – are transdiagnostic risk factors of psychopathology. Previous research has identified these two clinically relevant ruminative subtypes as phenotypically overlapping yet distinct constructs. Additional work has emphasized how these two ruminative subtypes have predictive value distinct from neuroticism, a personality trait that has strong relations with psychopathology and is often associated with rumination. However, no research has directly examined whether rumination is genetically distinct from neuroticism. Thus, the present study investigated the extent to which anger rumination, depressive rumination, and neuroticism share genetic and environmental influences. These analyses were conducted on 877 individuals from 439 same-sex twin pairs in the Colorado Longitudinal Twin Study. Seven subscales were taken from three rumination questionnaires administered at age 23 and used to create depressive and anger rumination latent variables. Neuroticism subscales from shortened versions of the Eysenck Personality Questionnaire administered at ages 16 and 21 were used to create a neuroticism latent variable. Multivariate Cholesky decompositions indicated common genetic and environmental influences on neuroticism, depressive rumination, and anger rumination. Genetic influences specific to rumination explained 20% of the variance of anger rumination and 7% of the variance of depressive rumination, although they were not statistically significant. Furthermore, depressive rumination had specific nonshared environmental influences after controlling for neuroticism and anger rumination, and anger rumination had specific nonshared environmental influences after controlling for neuroticism and depressive rumination. These results indicate that rumination is influenced by the same genetic variance as neuroticism, but both subtypes of rumination are distinguished by nonshared environmental influences. Building on these analyses, we plan to also examine whether the specific nonshared environmental influences and perhaps additive genetic variance on rumination predict internalizing and externalizing psychopathology. Our findings point to the importance of examining rumination as a multifaceted construct and deepen current understanding of the separability of rumination and neuroticism. Taken together, these findings suggest that a comprehensive understanding of these transdiagnostic risk factors must include an examination of both genetic and environmental influences.