Delineating genetic and environment effects on anxiety in adulthood: Application of a latent trait-state model

Although genetic and environmental factors play a key role in the long-term stability of anxiety, the extent to which the genetic and environmental determinants are best characterized by state- versus trait-like components is unclear. Also unclear is whether the genetic and environmental effects underlying trait and state components of anxiety differ across adult development. This study analyses data from twins (N = 4854) in the Washington State Twin Registry (WSTR) that completed a measure of anxious symptoms across seven waves during the COVID-19 pandemic in order to identify the genetic and environmental sources of stability and change in anxiety during adulthood. The sample was divided into three cohorts, representing early, middle, and late adulthood. Application of phenotypic latent trait-state models showed that the latent state component of anxiety accounted for most of the variance in young adulthood and late adulthood whereas the latent trait component accounted for the majority of variance in middle adulthood. Genetically informed models showed that nonshared environmental variance underlying the latent state component accounted for the greatest amount variance in early (50.99%) and late (88.50%) adulthood whereas genetic variance of the trait component accounted for the majority of variance (49.44%) in middle adulthood. These findings highlight different processes (i.e., state vs. trait) that account for stability of anxiety at different periods in adulthood.