Genomic Studies of Suicidal Thoughts and Behaviors in Latin American Populations: A Systematic Review

Suicide is a leading cause of death globally, with disproportionately rising rates in Latin America. Despite increasing global interest in the biology of suicidal behavior, Latin American and Hispanic/Latinx populations remain underrepresented in genomic research. In this systematic review, we synthesized current evidence on genomic studies of suicidality in these populations.

We reviewed molecular studies of suicidal ideation, suicide attempt, nonsuicidal self-injury, or suicide death among Latin American or Hispanic/Latinx individuals (PROSPERO registration: CRD42023416616). Eligible studies examined family risk, genetic, epigenetic, or transcriptomic markers. Searches were conducted in PubMed, SciELO, REDALyC, and regional journals. Synthesis used a narrative approach and random-effects meta-analyses when feasible. Risk of bias was assessed using the Newcastle-Ottawa Scale and the Q-Genie tool. A coauthorship network analysis was performed to characterize collaboration patterns.

Fifty-nine studies met inclusion criteria: 3 family, 50 genetic, 6 transcriptomic, and 3 epigenetic studies (categories not mutually exclusive). Candidate gene studies mainly examined serotonergic and stress-response pathways but yielded inconsistent results. Meta-analyses for TPH1 (rs1800532), HTR2A rs6313 (T102C), and 5-HTTLPR (rs25531) showed no significant associations. Recent genome-wide and polygenic score studies identified ancestry-specific loci, although small samples and limited functional annotation resources hindered follow-up. Transcriptomic and epigenetic studies have implicated neurodevelopmental and immune-related processes. Collaboration networks were dominated by a single hub, with limited cross-group integration.

Genomic research on suicidality in Latin America is growing but remains fragmented and underpowered. Increasing representative sampling, implementing ancestry-aware methods, and fostering collaborations are essential to advance research and inform prevention strategies in these populations.