Psychose et suicide : comment se développent-ils conjointement ? Une revue narrative

Objectives

Persons with psychosis are up to 20 times more likely to die by suicide than the general population. Nevertheless, the mechanisms underlying the association between psychosis and suicide remain poorly understood. This narrative review aimed to describe the mechanisms that have been explored in the literature to explain this association.

Materials and methods

A narrative review was conducted in Pubmed and Google Scholar in January 2024 using keywords related to psychosis and suicide. The keywords used for psychosis were: “psychosis”, “psychotic”, “psychotic symptoms”, “psychotic experiences”, “psychotic-like experiences”, “delusions”, “hallucinations”; and for suicide: “suicid*”. Additional keywords were used in Google Scholar to refine the search: “association” OR “mechanisms” OR “pathways” OR “risk factors”. References of selected articles were consulted. The results of the studies have been organized according to the four hypothesized mechanisms explored in the literature.

Results

The four hypotheses explored in the literature were: (1) causal link from psychosis to suicidality, (2) causal link from suicidality to psychosis or bidirectional link, (3) shared risk factors for psychosis and suicidality, (4) indirect link between psychosis and suicidality. In general, studies show that across the continuum of psychosis (from psychotic experiences to schizophrenia spectrum disorders), psychosis symptoms, especially auditory hallucinations and delusions, increase the risk of suicide thoughts and behaviors. Certain factors emerged as being particularly important in understanding the association between psychosis and suicide, whether as confounders or mediators, such as cognitive skills, traumatic events, psychological distress, depressive symptoms and substance use disorder. Recent evidence seems to support the existence of a bidirectional association between psychosis and suicide risk.

Discussion and conclusion

Each hypothesis has been explored and supported by at least a few studies, suggesting that the mechanisms underlying the association between psychosis and suicide are potentially multiple and multifactorial. Identifying persons at risk of psychosis among those presenting suicidal thoughts and behaviors, as well as implementing early suicide prevention strategies among persons with psychosis symptoms, could respectively contribute to delaying/preventing the frank onset of a mental health disorder and reduce the risk of suicide. Further, suicide risk assessment and prevention in individuals with psychosis should take into account factors that have emerged as being important in the association between these two phenomena. In order to improve our understanding of the association between psychosis and suicide risk, several recommendations have been made for future research, such as considering the developmental stage and the stage of illness to assess potential mechanisms, and considering additional potential mediators (e.g., stigma, treatment compliance, social support, functioning and symptom severity).