Preschool-Onset Major Depressive Disorder as a Strong Predictor of Suicidal Ideation and Behaviors Into Preadolescence.

OBJECTIVE:Suicidal thoughts and behaviors (STBs) in children are an escalating public health concern. This study focused on 1 understudied candidate risk factor, namely, preschool-onset major depressive disorder (PO-MDD), as a predictor of persistent and emerging STBs from early childhood into preadolescence. METHOD:Participants were 137 children 8 to 12 years of age who met criteria for PO-MDD when they were 3 to 6 years of age, and a nondepressed sample of 53 age-, income-, and sex-matched peers. STBs were reported by caregivers (preschool, preadolescence) and children (preadolescence) using age-appropriate diagnostic interviews. RESULTS:By preadolescence, children who had PO-MDD were 7.38 times more likely than their peers to have endorsed STBs after early childhood (p < .001; 67.9% vs 22.6%), including 6.71 times more likely to have engaged in suicide behaviors/attempts (p = .012; 21.9% vs 3.8%); they were also 8.98 times more likely to have endorsed STBs over the prior month (p = .005; 26.3% vs 3.8%). Similar findings emerged when limiting the PO-MDD group to children without preschool STBs, and when controlling for externalizing comorbidities, implicating PO-MDD as a unique diagnostic predictive risk factor. However, children who had PO-MDD with STBs were 3.46 times more likely than children who had PO-MDD without STBs to endorse later STBs (p = .018; 83.1% vs 54.2%), indicating substantial continuity of preschool STBs alongside strikingly high rates of emerging STBs into preadolescence. CONCLUSION:PO-MDD is a strong risk factor for the emergence and persistence of STBs into preadolescence. Children with PO-MDD would likely benefit from increased suicide screening, proactive safety planning, and early interventions.