A genome-wide association study of suicidal behavior

Area of Science:

• Genetics
• Neuroscience
• Psychiatry

Background:

• Genome-wide association studies (GWAS) have had limited success in identifying genetic risk factors for suicidal behavior (SB).
• Previous study designs may have focused on outcomes other than SB, potentially obscuring relevant genetic associations.

Purpose of the Study:

• To conduct a GWAS specifically on suicidal behavior, including completed suicides and nonfatal suicide attempts, to identify associated genetic markers.
• To compare genetic associations between suicide attempts and completed suicides using psychiatric and healthy controls.

Main Methods:

• A consortium of researchers analyzed data from 577 cases (suicide attempters and suicides) and 1,233 controls (psychiatric and healthy).
• Logistic regression was employed to test genotype-suicidal behavior associations, with separate analyses for suicide attempts and completed suicides.
• Pathway analysis was performed to explore biological pathways implicated in suicidal behavior.

Main Results:

• No single nucleotide polymorphisms (SNPs) reached genome-wide significance for SB.
• Several SNPs within the STK3, ADAMTS14, PSME2, and TBX20 genes showed suggestive significance (P < 1 × 10⁻⁵).
• Top candidate genes identified include ADAMTS14 and PSME2 (inflammatory response), STK3 (neuronal cell death), and TBX20 (motor neuron development), with no overlap with ideation analysis.

Conclusions:

• The genetic architecture of suicidal behavior likely involves numerous genes with small effect sizes.
• ADAMTS14, PSME2, STK3, and TBX20 represent novel candidate genes for suicidal behavior that require further validation.
• Future research should focus on these candidate genes and pathways to better understand the genetic underpinnings of SB.