Self-harm, suicidal ideation, and the positive symptoms of psychosis: Cross-sectional and prospective data from a national household survey

Background: Schizophrenia is associated with premature mortality, partly through increased suicide rates. Aims: To examine (1) if persecutory ideas, auditory hallucinations, and probable cases of psychosis are associated with suicidal thoughts or attempts cross-sectionally and prospectively, and (2) if such links are mediated by specific affective factors (depression, impulsivity, mood instability). Method: We analysed the 2000, 2007, and 2014 British Adult Psychiatric Morbidity Surveys (APMS) separately. Measures of psychosis provided independent variables for multi-stage logistic regressions, with suicidal thoughts and attempts as dependent variables. We also conducted analyses to assess mediation by affective variables, and longitudinal analyses on a subset of the 2000 dataset. Results: In every dataset, persecutory ideas, auditory hallucinations and probable psychosis were associated cross-sectionally with lifetime suicidal attempts and thoughts, even after controlling for confounders, with a single exception (persecutory ideation and suicide attempts were unconnected in APMS 2014). Cross-sectional associations between auditory hallucinations and suicidal phenomena were moderated by persecutory ideation. In the 2000 follow-up, initial persecutory ideas were associated with later suicidal thoughts (O.R. 1.77, p < 0.05); there were no other longitudinal associations. In the 2007 and 2014 datasets, mood instability mediated the effects of psychotic phenomena on suicidality more strongly than impulsivity; depression was also an important mediator. There were appreciable direct effects of positive symptoms on suicidal thoughts and behaviour. Conclusions: Improving psychotic symptoms and ameliorating co-morbid distress may in itself be effective in reducing suicidal risk in schizophrenia. Given their potential mediating role, mood instability and depression may also be targets for intervention.

Automated summary

The study revealed that persecutory ideas, auditory hallucinations, and psychotic symptoms are associated with suicidal behavior, particularly in patients with schizophrenia. Mood instability and depression may play a mediating role in the impact of psychotic phenomena on suicide behavior.