Moderating effects of positive symptoms of psychosis in suicidal ideation among adults diagnosed with schizophrenia

Abstract

Background: Suicide is among the leading causes of death for adults diagnosed with schizophrenia, with risk estimates being over eight folds greater than the general population. While the majority of research to date focuses on the role of symptoms of depression in suicide risk, there is a lack of consensus and understanding of the relationship between positive symptoms of psychosis and both suicidal ideation and attempt. The current study examined pathways of influence between symptoms of depression, positive symptoms of psychosis (i.e. hallucinations and delusions), hopelessness, and suicidal ideation among a population of adults diagnosed with schizophrenia.

Methods: Data were obtained from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE; n=1460) at baseline. Suicidal ideation, hopelessness, and symptoms of depression were measured by the Calgary Depression Scale (CDRS) and hallucinations and delusions by the Positive and Negative Syndrome Scale (PANSS). Data were analyzed with Structural Equation Modeling (SEM) using Mplus 7.

Results: Symptoms of depression, positive symptoms of psychosis, and hopelessness independently predicted suicidal ideation. Hopelessness significantly mediated the relationship between symptoms of depression and suicidal ideation. Lastly, positive symptoms of psychosis were found to moderate the relationship between symptoms of depression and suicidal ideation.

Conclusions: The current study provides evidence for the role that positive symptoms of psychosis (specifically hallucinations and delusions) play in suicidal ideation, pointing towards the implication that beyond symptoms of depression, positive symptoms must be evaluated for and treated.

Keywords: Positive symptoms of psychosis; Schizophrenia; Structural equation modeling; Suicidal ideation; Symptoms of depression.