Developmental Trajectories of Suicidality in Sexually Diverse and Heterosexual Adolescents: Findings From the Quebec Longitudinal Study of Child Development: Trajectoires développementales de suicidalité chez les adolescents hétérosexuels et de la di

IntroductionSexually diverse adolescents report higher suicidality (ideation and attempts) than their heterosexual peers, but information on the onset and course of suicidality from early adolescence to young adulthood among contemporary sexually diverse individuals remains limited. This study traces suicidality trajectories across this critical developmental period, comparing sexually diverse and heterosexual adolescents both overall and by sex assigned at birth.MethodsData was drawn from the Quebec Longitudinal Study of Child Development, an ongoing population-based prospective birth cohort. This study included 1,505 participants who self-reported their sexual attraction at ages 15-17 (2013-2015) and past-year suicidal ideation and attempts using 3-items at ages 13, 15, 17 and 23 (2011-2021) from which a suicidality severity score was derived.Results11.5% of the sample (n = 173, 60.5% female) reported sexually diverse attraction. Growth curve modelling tested the random effect of sexually diverse (vs. heterosexual) attraction on suicidality severity intercept, linear and quadratic latent growth factors. Age-specific contrasts in suicidality severity between sexually diverse and heterosexual adolescents were also examined. Compared to heterosexual adolescents, sexually diverse adolescents showed a steeper increase in suicidality severity from ages 13 to 17, and declining yet persisting disparities from ages 17 to 23. Although developmental trajectories differed across sexually diverse males and females, both experienced greater suicidality severity during adolescence compared with heterosexual peers.DiscussionOur findings point to a developmental trajectory in which sexually diverse adolescents, particularly females assigned at birth, experience elevated suicidality that persists into young adulthood. Targeted and timely interventions during this critical developmental period are essential for suicide prevention.