Background and Hypothesis
Suicide is a leading cause of death in youth and is often preceded by suicidal ideation (SI) and non-suicidal self-injury (NSSI). Identifying early markers of risk for SI and NSSI could improve timely identification of at-risk individuals.

Study Design
Children (mean age 11.9, SD 0.2) at familial high risk of schizophrenia (N = 171), or bipolar disorder (N = 104), and controls (N = 174) were assessed for psychotic experiences (PE), SI, NSSI, and Axis I mental disorders in face-to-face interviews in early and middle childhood (age 7 and 11).

Study Results
Having 2 types of early childhood PE predicted middle childhood SI after accounting for previous SI, NSSI, and mental disorders (OR 2.8, 95% CI 1.1–6.9; P = .03). Two PE predicted NSSI (OR 3.0, 95% CI 1.2–7.7; P = .02) in excess of previous SI, NSSI, mental disorders, and familial risk. Persistent and incident PE predicted SI (OR 3.2, 95% CI, 1.1–8.8; P = .03; OR 3.8, 95% CI, 1.3–11.5; P = .02) in the fully adjusted model. Nineteen percent of children with persistent PE reported middle childhood SI vs 3.8% of those who never reported PE. In children with early childhood mental disorders, those who reported 2 PE had 4.4-fold increased odds of later SI (95% CI, 1.2–16.7; P = .03) after adjustments. PE were nondifferentially associated with outcomes across familial risk groups.

Conclusions
Early childhood PE index elevated risk for subsequent SI and NSSI beyond what can be attributed to presence of mental disorders. Mental health screenings and clinical assessments should include early childhood PE.