Growth Trajectories of Suicide Ideation and Attempt in a Population-Based Cohort from the United States

<b><i>Objective</i></b>: Suicidal thoughts and behaviors (STB) constitute high public health concerns. Understanding the longitudinal trajectories of STB from adolescence to adulthood as a function of sex, ancestry, and genetic liability would improve our knowledge and the design of population-based prevention/intervention. <b><i>Methods</i></b>: We used data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) and included participants of European (EA, N = 4,905) and African (AA, N = 1,654) ancestry. We evaluated the growth trajectories of suicide ideation and suicide attempt from age 12 to 40 separately in participants of EA and AA and assessed the roles of sex and genetic liability, indexed using polygenic scores (PGS). <b><i>Results</i></b>: Quadratic growth models including an age-by-sex interaction fit the data best in both ancestral groups. Results indicated an overall decrease of STB from adolescence to adulthood, a stabilization between ages 25-35, and a tendency to increase after age 35. Sex differences were evidenced by higher baseline levels of STB and sharper decreases across ages in females. Including PGS improved the model fit and was related to baseline levels of STB. <b><i>Conclusions</i></b>: Adolescence constitutes a high-risk period for the development of STB, particularly in females and those with high genetic liability. Though we observed a stabilization of STB in adulthood, another risk period may arise after age 35.