Features of suicidal ideation that predict subsequent suicide attempt in three longitudinal cohorts.

Objective: Although suicidal ideation (SI) precedes suicide attempt (SA), most people who experience SI do not attempt suicide. There may be distinct profiles of SI that are differentially associated with SA. The current study aimed to identify whether specific attributes of SI were prospectively associated with SA across three longitudinal cohorts. Method: Three Australian cohorts were examined: a population-based cohort of adults with SI (n=836, Mage=36 years, 67% women), a school-based cohort of Australian adolescents with SI (n=916, Mage=14 years, 58% women) and a clinical sample (psychological outpatients, n=103, Mage=29 years, 68% women). All participants completed the Suicidal Ideation Attributes Scale (SIDAS), assessing: frequency, controllability, closeness to making an attempt, distress and functional impairment associated with SI. Participants were followed for 12 months in the population samples and approximately 6 months in the clinical sample to assess occurrences of SA. Results: Significant associations between each of the SI attributes and subsequent SA were observed, although these associations were non-significant in logistic regression models that included all five attributes. Total SIDAS scores, indicating severity of suicidal ideation, were consistently associated with later SA (p≤0.001), and findings were largely consistent across the three cohorts. Conclusion: Different attributes of SI significantly predicted subsequent attempts, although no single attribute had a consistently significant independent association. There was evidence that total severity scores were more robustly associated with subsequent SA than individual attributes. Consequently, assessment of SI severity may be preferable over single-item indicators when providing clinical care for people at risk of suicide.