Can't get you out of my head: Persistence and remission of psychotic experiences in adolescents and its association with self-injury and suicide attempts

Background: Persistent psychotic experiences (PEs) may increase risk for mental disorders, non-suicidal self-injury (NSSI), and suicide attempts, relative to PEs that are more transient and remitting in nature. Most investigations of PE persistence have incorporated only two waves of data, and have not investigated the persistence of different PE subtypes and their association with future NSSI and suicide attempts. This study aimed to investigate the association between PE persistence, NSSI, and suicide attempts using three waves of prospective data. A secondary aim was to investigate potential reverse pathways where self-injurious behaviour (and its persistence) instead precedes subsequent PE occurrence. Method: Participants were 1100 adolescents (12–17 years) from an Australian prospective cohort study; with three time points over two years. The Self-Harm Behaviour Questionnaire was used to assess NSSI and suicide attempts. Four PE subtypes (auditory hallucinatory experiences [HEs], and three delusional experiences) were assessed using the Diagnostic Interview Schedule for Children. Logistic regression analyses were conducted where PEs was grouped into five categories according to their persistence across the three waves of data. Analyses were adjusted for sociodemographics and substance use. Results: Overall, persistence of PEs (with endorsement of PE across two or three waves) was associated with the highest risk of incident NSSI and suicide attempts at 1- and 2-year follow-up (OR range: 2.57–12.25), whereas remitted PEs (with endorsement of PE at baseline only) were not associated with increased risk of future NSSI or suicide attempts. This pattern of association was evident for auditory HEs but not for most other PE subtypes; although some estimates had wide confidence intervals. There was no support for reverse temporality. Conclusion: Our findings support and extend the two-wave cohort literature demonstrating that PEs which persist over time are more robust predictors of future NSSI and suicidal behaviour. Auditory HEs that are persisting in nature are an important but under-recognised risk factor for NSSI and suicide attempts during adolescence, and current findings should inform clinical guidelines into the predictors of self-harm and suicide risk at this life stage.