Illness, Injury or Assault Linked to Higher Suicide Attempt Risk in Adults With Suicidal Thoughts

A serious illness, injury or assault in the preceding six months was associated with a 68 percent higher hazard of a suicide attempt over the following two years among Australian adults who were already experiencing suicidal thoughts, according to a three-year longitudinal cohort study published in SSM – Mental Health. The association, however, did not survive statistical adjustment for the strongest predictors of future attempts: a lifetime history of suicide attempt and the severity of current suicidal ideation.

The study, led by Monica Gendi and Philip J. Batterham at the University of New South Wales and the Australian National University, drew on the LifeTrack Project, an online cohort of Australian adults recruited largely through social media advertising between July and November 2023. All participants reported suicidal ideation within the past 30 days at baseline and had made no suicide attempt in that period. After data-quality screening removed potentially fraudulent responses, the baseline sample stood at 792 people, and the analytic sample for the main models comprised 700 adults with a mean age of 37.46 years.

Participants completed online surveys every six months for three years, covering sociodemographics, suicidal ideation and attempts, mental and physical health, stressful and traumatic events, support seeking and cognitive styles. Stressful life events were measured with a modified version of the Life Events Checklist, in which respondents ticked events experienced in the past six months. Categories included serious personal illness, injury or assault; serious illness or injury to a close relative or friend; death of a parent, child, partner or close friend; the end of a steady relationship or a serious relationship problem; work-related crises or job loss; a major financial crisis; unstable housing or homelessness; discrimination; and other events.

Suicide attempts during follow-up were assessed with items adapted from the Youth Risk Behavior Survey, asking whether participants had tried to kill themselves in the past six months and, if so, how many times and how recently. Survival time was calculated from baseline to the first reported attempt. Cox proportional hazard regression models then tested whether baseline life events predicted the hazard of a first attempt during the 24 months after baseline, with age and gender controlled in the first step and baseline ideation severity, lifetime suicide attempt and lifetime trauma added in a second step.

Over 24 months, 104 participants, or 15 percent of the analytic sample, reported at least one suicide attempt. Fifty reported an attempt within the first six months, 40 between six and 12 months, 44 between 12 and 18 months, and 39 between 18 and 24 months. In unadjusted bivariate comparisons, younger age, more severe baseline suicidal ideation, a lifetime history of suicide attempt and lifetime trauma were all significantly associated with reporting an attempt during the study, as were baseline reports of serious illness, injury or assault and of experiencing discrimination.

In the first Cox model, which controlled only for age and gender, experiencing a serious illness, injury or assault in the preceding six months was associated with a 68 percent increased hazard of suicide attempt over the following 24 months compared with those who did not report such an event (hazard ratio 1.68, 95 percent confidence interval 1.08 to 2.60, p = 0.021). Younger age also carried higher hazard, with a 3 percent decrease in hazard for each additional year of age (hazard ratio 0.97, 95 percent confidence interval 0.95 to 0.99, p < 0.001), and gender was not significant. When baseline suicidal ideation severity, lifetime suicide attempt and lifetime trauma were added, the illness, injury or assault effect fell to a hazard ratio of 1.52 (95 percent confidence interval 0.97 to 2.36) and became non-significant at p = 0.066.

The strongest predictor in the adjusted models was a lifetime history of suicide attempt, which carried 4.53 times the hazard of a subsequent attempt during follow-up (95 percent confidence interval 2.59 to 7.90, p < 0.001). Each unit increase on the five-item Suicidal Ideation Attributes Scale, which ranges from 0 to 50, was associated with a 4 percent increase in hazard (hazard ratio 1.04, 95 percent confidence interval 1.02 to 1.06, p < 0.001). Lifetime trauma alone was not significantly associated with attempts after these adjustments, and age remained significant with the same 3 percent per-year reduction in hazard.

A second analysis summed the number of life-event categories each participant endorsed and found a dose-response pattern: each additional category was associated with a 14 percent increase in the hazard of a subsequent attempt (hazard ratio 1.14, 95 percent confidence interval 1.03 to 1.25, p = 0.011), again before adjustment for ideation severity and prior attempt. Once those clinical variables entered the model, the cumulative life-event effect was attenuated to non-significance (hazard ratio 1.03, 95 percent confidence interval 0.93 to 1.14, p = 0.568). Sensitivity analyses using multiple imputation to account for missing baseline data, with 20 imputed datasets and a sample of 740, reproduced the same pattern of results.

The authors interpret the findings through established theoretical frameworks, including the Interpersonal Theory of Suicide and the Integrated Motivational-Volitional Model, which propose that painful and provocative experiences may raise acquired capability for suicide and thereby increase the likelihood that suicidal ideation progresses to an attempt. The observed association between personal illness, injury or assault and later attempts is consistent with that prediction, the researchers note, but they caution that the study did not measure suicide capability directly, so the results cannot be taken as evidence for those specific mechanisms. They also distinguish stressful life events from traumatic events, arguing that the two are conceptually separate and that life events explained variance in suicidality beyond trauma in prior work, although in this cohort those associations did not persist after adjustment for prior attempt.

Several limitations temper the conclusions. The cohort was self-selected through social media advertising, with more than half of participants reporting a previous suicide attempt and about two-thirds reporting previous trauma, so the sample may not represent all Australian adults with recent suicidal ideation. The life events checklist assigns equal weight to the same event type regardless of context or severity, cannot distinguish a single acute episode from a chronic condition, and did not assess the distress each event caused. Some event categories were endorsed too rarely to test their associations with adequate statistical power, the identified effects were small and could have been attenuated further under correction for multiple comparisons, and attrition before the first follow-up was itself linked to relationship breakdown, unstable housing and discrimination, which may have unpredictably biased estimates for those events. The authors conclude that serious illness, injury or assault appears to be a prospective risk factor for subsequent attempts among people with existing suicidal ideation, but one that is not robust once previous attempts and ideation severity are accounted for, and they call for research into whether contact with health services after such events could offer opportunities for targeted suicide prevention among people not otherwise receiving mental health care.

Subject of Research: Prospective associations between specific stressful life events and the transition from suicidal ideation to suicide attempt in Australian adults

Article Title: The association of specific stressful life events with subsequent suicide attempts: Longitudinal cohort study

Article References: Gendi, M., Varley, D., Leach, L. S., Farrer, L. M., Borschmann, R., Calear, A. L., & Batterham, P. J. (2026). The association of specific stressful life events with subsequent suicide attempts: Longitudinal cohort study. SSM – Mental Health, 10, Article 100725. https://doi.org/10.1016/j.ssmmh.2026.100725

Image Credits: AI Generated

DOI: 10.1016/j.ssmmh.2026.100725

Keywords: suicide attempt, suicidal ideation, stressful life events, longitudinal cohort study, Cox proportional hazards, LifeTrack Project, illness and injury, lifetime suicide attempt, mental health, risk prediction, Australia, SSM – Mental Health