No interaction between polygenic scores and childhood trauma in predicting suicide attempt in schizophrenia

Abstract

Background: Approximately 5% of patients with schizophrenia commit suicide, and 20% to 40% of them have at least one suicide attempt during their lifetime. Previous research has identified childhood trauma as a potential risk factor for suicide attempt in schizophrenia. The Psychiatric Genetics Consortium found 108 common genetic risk loci associated with schizophrenia. Moreover, familial, adoption, and twin studies suggested that suicidal behaviour is under genetic influence.

Objective: Our objective was to determine the effect of childhood trauma and schizophrenia polygenic risk in leading to suicide attempt, as well as to determine any interaction effect between the polygenic scores with childhood trauma.

Methods: The study design was cross-sectional and retrospective considering lifetime suicide attempt as the main dependent variable. Childhood trauma was assessed using the Childhood Trauma Questionnaire. Polygenic Risk Score calculation was done using the genome-analysis toolkit, PLINK. The suicide attempts were recorded using the Columbia Suicide Severity Rating Scale.

Results: We included 224 subjects in our sample and 93 attempted suicide at least once in their lifetime. When comparing the weighted scores in attempters and non-attempters, we found no association (p > .05).

Conclusion: Although our results do not support our hypothesis, the interaction analysis of genetic risk for schizophrenia in combination with the history of childhood trauma requires larger samples with high-quality suicide risk assessment.

Keywords: CTQ; Genetics; Polygenic scores; Polymorphisms; Schizophrenia; Suicide.