Psychotic experiences and incident suicidal ideation and behaviour: Disentangling the longitudinal associations from connected psychopathology

This study examines the longitudinal associations between psychotic experiences (PE) and incident suicidal ideation and behaviour in the general population, and to what degree the association may be confounded by non-psychotic psychopathology. Data from three prospective, general population cohorts were combined into one dataset (n=15,837) and analysed using logistic regression, controlling for continuous measures of depression, anxiety and mania symptoms. Analyses were conducted in the entire sample, and in subsamples stratified by presence or absence of mental disorders. The presence of PE at baseline increased the risk of incident suicidal ideation and behaviour. However, adjustment for dimensional measures of psychopathology reduced effect sizes, although PE remained significantly associated with suicide attempts. Further examination of the associations revealed that PE were only associated with suicide attempts in individuals with at least one mental disorder. Similarly, in individuals without mental disorders, the risk of suicidal ideation increased as PE co-occurred with more symptom domains. The results of this study confirm that individuals with PE are at increased risk of suicidal ideation and behaviour. However, these associations are not specific, but reflect the increased risk of suicidal ideation in individuals with subthreshold multidimensional psychopathology and suicide attempts in individuals with co-occurring mental disorders.