Suicidal Ideation and Non-suicidal Self-injury Following Childhood Psychotic Experiences in Adolescents at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 15.

BACKGROUND AND HYPOTHESIS: Suicidal ideation (SI) and non-suicidal self-injury (NSSI) peak in adolescence and are strong predictors of future suicide. Identifying childhood risk markers for SI and NSSI could improve early suicide prevention. STUDY DESIGN: Adolescents (mean age 15.9, SD 0.4) at familial high risk of schizophrenia (n = 145) or bipolar disorder (n = 94), and population-based controls (n = 154) were assessed for psychotic experiences (PE) in early (until age 7) and middle (age 7-11) childhood, and for SI and NSSI in early childhood, middle childhood, and adolescence (age 11-15). STUDY RESULTS: Middle childhood PE predicted adolescent SI (OR 3.8; 95% CI, 2.0-7.4; P < .001) and NSSI (OR 2.8; 95% CI, 1.4-5.5, P = .004) after accounting for previous SI and NSSI, childhood mental disorders, current symptom severity, and familial risk. Persistent and incident but not remittent childhood PE predicted adolescent SI (OR 5.5; 95% CI, 2.2-13.8; P < .001 and OR 4.3; 95% CI, 1.6-11.3; P = .003) and NSSI (OR 3.3; 95% CI, 1.3-8.6; P = .01 and OR 3.2; 95% CI, 1.2-8.7; P = .02) in the fully adjusted models. Among children without childhood SI and NSSI, those with persistent PE had nearly 6-fold increased odds of incident adolescent SI (OR 5.7; 95% CI, 1.7-19.0; P = .005) relative to those without childhood PE. Psychotic experiences were non-differentially associated with SI and NSSI across familial risk groups. CONCLUSIONS: Childhood PE, particularly when persistent, mark risk for adolescent SI and NSSI beyond the effects attributable to known risk factors. Persistent childhood PE are strong risk markers for incident adolescent SI. Childhood PE should be considered in suicide risk assessments in general and familial high-risk populations.