GWAS analysis of suicide attempt in schizophrenia: Main genetic effect and interaction with early life trauma

Objectives: Suicide attempt in schizophrenia is an important clinical issue. We performed a genome-wide association study to identify genetic markers, which increase the risk for suicide attempt in schizophrenia.

Methods: Suicide attempt lifetime was assessed in 121 schizophrenia patients and defined by the means of the Columbia Suicide Severity Rating Scale and the Beck Scale for Suicidal Ideation. Genotype distribution of 1,205,383 single nucleotide polymorphisms (SNPs) in patients with suicide attempt lifetime (n=53) was compared to that in patients without any suicide attempt lifetime (n=68). The same SNPs were analyzed in interaction with childhood trauma.

Results: None of the variants reached genome-wide significance after multiple test correction. However, the most nominally significant SNP in the in the main genetic model was rs12895203 (p=0.00001) and the top SNP interacting with Childhood Trauma Questionnaire was the marker rs7897059 (p=0.00005). The odds-ratio of the top SNP in the main-genetic effect model was 3.91 and in the gene-early trauma interaction model was 1.13.

Conclusions: Although our data need to be interpreted carefully owing to the small numbers in this cohort and because the results reached just the nominal significance, they suggest that a combination of genetic markers and early life stress might indeed be used to identify patients at risk for suicide attempt.