Background: Emotion-related impulsivity – difficulty controlling impulses when emotionally distressed – is implicated in both suicidal and self-injurious behaviour and ideation, however, the extent of this association is yet to be determined longitudinally. This systematic review and meta-analysis addressed the following question: What is the association between emotion-related impulsivity and later suicidal and self-injurious thoughts and behaviour?
Method: A systematic review was conducted in accordance with PRISMA guidance (registered protocol on Prospero CRD42024505066). Seven relevant databases were searched on January 29, 2024. Studies had to be original peer reviewed research, published in English, with a quantitative prospective design, and included suicidal and/or self-injurious behaviour or ideation as an outcome and emotion-related impulsivity as a predictor, moderator or mediator. Titles, abstracts and full texts were screened in full by one reviewer, 20% of which were blindly screened by a second reviewer. Narrative synthesis was used to summarise study trends in relation to socio-demographic characteristics. A random effects model was used for the meta-analysis to obtain an overall estimate of the association between emotional impulsivity and later suicide outcomes.
Results: Twelve papers were eligible for inclusion. Based on preliminary analysis, out of the 12 studies, eight were eligible for inclusion in a meta-correlation. The pooled sample size was 7778 participants with an average follow-up time of seven months. A significant small, pooled effect size was found (r = 0.16, CI = 0.04, 0.28), with significant heterogeneity indicated between the studies included in the meta-analysis. The narrative synthesis is ongoing however studies were exclusively based in high-income countries and participants were on average 21.8 years (SD = 7.1) years old.
Conclusions: There is some consistency with how emotion-related impulsivity is operationalised and measured. Most studies focussed on non-suicidal self-injury as the outcome variable. Overall, the results are consistent with models of suicidal behaviour that emotional impulsivity is a significant risk factor for later suicide-related outcomes. With the average follow-up time, it is possible that we did not capture the proximal effects of emotional impulsivity on suicide outcomes. Future research would benefit from establishing the individuals’ intended outcome of their self-injurious behaviour.