This article is a meta-analysis of several studies investigating neurocognitive deficits linked to suicidal thoughts or suicidal attempts. The aim of this analysis was to state on the presence of a neurocognitive differences between individuals experiencing suicidal thoughts and individuals who actually attempted suicide in the past. The authors emphasise the necessity of this distinction because at the time, most risk factors highlighted by current research about suicide are more linked to suicidal thoughts than suicidal acts. This is an issue because most people who have suicide ideation will not attempt to commit suicide (Fergusson et al., 2003 ; ten Have et al., 2009). Risk factors for suicide ideation might indeed be distinct from risk factors for suicide attempts, but little is known about risk factors in suicidal acts. This article plans to investigate the possibility of neurocognitive abilities differences as a risk factor of suicide attempts, such as executive dysfunction. One of the authors argument is that the fact that impaired executive functions leads to reduced ability to regulate negative emotions, finding alternative solutions to an issue and inhibitate behaviours might explain the transition from suicidal thoughts to suicide attempts. Indeed, a former meta-analysis of 25 studies (Richard-Devantoy et al., 2014) observed that individuals with previous suicidal attempts had worse performance than control subjects on 3 tasks measuring executive functions : Stroop task, categorical verbal fluency and Iowa Gambling Task. Plus, results from individual studies showed that individuals with previous suicide attempts have an attentional bias directed on suicide-related words, a bias able to predict suicide attempts in these individuals (Becker et al. 1999, Nock & Banaji, 2007).
To assess the presence of neurocognitive abilities differences between suicidal attempters and suicidal ideators, a meta-analysis was performed over 13 studies on different neurocognitive abilities : global cognitive functioning, intelligence, executive functions, processing speed and memory. A longitudinal study across army soldiers was also included in the review.
Results showed that ideators and attempters performed similarly on all neurocognitive abilities except for inhibition and decision making : ideators performed better on these tasks than attempters. These process didn’t differ between ideators and nonsuicidal individuals though. Global cognitive functioning was also examined longitudinally in a large sample or Army soldiers : results showed that global cognitive functioning predicted suicide in ideators as much as in attempters.
However, results showed differences between ideators and nonsuicidal individuals on processing speed, global executive functions and global cognitive functioning. Intelligence measures also showed that ideators obtained better scores than nonsuicidal individuals. An explanation may be that sever cognitive impairment could prevent individuals from having suicidal thoughts because thinking about it may require several cognitive abilities (self-awareness, time perspective and planning).
Mains limits to this meta-analysis is the small number of studies on this thematic, and also that methodological variation across the studies selected prevent from definitive conclusions on the relationship between neurocognitive abilities on suicide ideation and suicide attempts. Therefore, future studies should : consider separately risk factors predictors of suicidal ideation and suicide attempts, use larger sample size, use validated and precise neurocognitive functioning measures, and examine longitudinal prediction of death by suicide in addition to cross-sectional design.
Vocabulary learned :
Odds = les chances
Umbrella term = mot parapluie
Overlapping = chevauchement
Source : Saffer, B. Y., & Klonsky, E. D. (2018). Do neurocognitive abilities distinguish suicide attempters from suicide ideators? A systematic review of an emerging research area. Clinical Psychology: Science and Practice, 25(1), Article e12227. https://doi.org/10.1037/h0101751
Author : MERCIER Alice