Suicide attempts: genetic and environmental risk factors, impact, and healthcare utilization—an analysis of nationwide data

ABSTRACT Background Suicide is a major public health challenge, and a suicide attempt is an indicator of future mortality. This study provides a comprehensive analysis of initial suicide attempts. Methods Using Swedish national registers, we conducted a population-based cohort study of 3.7 million individuals followed from age 10 to a maximum age of 57. Suicide attempts were identified in hospital and death registers using ICD self-harm codes (intentional, with lethal methods, or leading to hospitalization or death). We investigated incidence, risk factors, outcomes, and familial aggregation, heritability, genetic correlations with psychiatric disorders, and healthcare visits in the month before and after initial suicide attempt. Findings The lifetime risk of suicide attempt in the study population was 4.6%, with greater risk in females and highest risk among ages 18-24. Overdose/poisoning were the most common methods. Prior history of psychiatric disorders, general medical diseases, and adverse life events were associated with increased risk of initial suicide attempt, while higher socioeconomic status was protective. Individuals with an initial suicide attempt were at substantially elevated risks of subsequent attempts (hazard ratio, HR, 23.4), suicide mortality (HR 16.4), and all-cause mortality (HR 7.3). One in ten families in Sweden had at least one individual who attempted suicide, and it tended to aggregate within families. The estimate of heritability was 42%, and genetic correlations of suicide attempts with psychiatric disorders ranged 0.48-0.85. At least 60% of those who made an initial suicide attempt had a healthcare contact in the month preceding the attempt. Interpretation The study provides comprehensive insights into suicidal behavior. Suicide attempts are major markers of poor mental health and risk for subsequent morbidity and mortality; indeed, they may carry the greatest mortal risk seen in clinical psychiatry. Our results underscore the need for systematic prevention efforts for individuals who have recently attempted suicide.