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.

PFS is a paid advisor and shareholder for Neumora Therapeutics. CMB received royalties from Pearson Education, Inc. HL received grants from Shire Pharmaceuticals; personal fees and serving as a speaker for Medice, Shire/Takeda Pharmaceuticals and Evolan Pharma AB; all outside the submitted work. HL is editor-in-chief of JCPP Advances. Co-authors declare no conflict of interest.

This study was supported by: The Suicide Prevention Institute at the University of North Carolina, Chapel Hill, NC, USA; the Swedish Research Council (award D0886501 to PFS); US National Institutes of Mental Health (R01 MH123724 to PFS); and the European Research Council (grant 101042183 to YL). CMB is supported by NIMH (R56MH129437; R01MH120170; R01MH124871; R01MH119084; R01MH118278; R01 MH124871); Brain and Behavior Research Foundation Distinguished Investigator Grant; Swedish Research Council (award: 538-2013-8864); and Lundbeck Foundation (Grant no. R276-2018-4581). AB is supported by the Swedish Research Council for Health, Working life and Welfare (Grant: 2022-00126) and Nordforsk (Grant: 147386). BMD is supported by the American Foundation for Suicide Prevention.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study was approved by the Swedish Ethical Review Authority (No. 2020-06540).

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The raw data are protected and are not available for sharing due to data privacy laws. For the Swedish register data, researchers can apply for data access at Statistics Sweden (SCB, https://www.scb.se/en/) and The National Board of Health and Welfare (Socialstyrelsen, https://www.socialstyrelsen.se/)