Suicidal behaviour and cognition: A systematic review with special focus on prefrontal deficits

Suicide is a major health concern worldwide, thus, identifying risk factors would enable a more comprehensive understanding and prevention of this behaviour. Neuropsychological alterations could lead to difficulties in interpreting and managing life events resulting in a higher risk of suicide.

A systematic literature search from 2000 to 2020 was performed in Medline (Pubmed), Web of Science, SciELO Citation Index, PsycInfo, PsycArticles and Cochrane Library databases regarding studies comparing cognition of attempters versus non-attempters that share same psychiatric diagnosis.

1.885 patients diagnosed with an Affective Disorder (n = 1512) and Schizophrenia/ Schizoaffective Disorder (n = 373) were included. In general comparison, attention was found to be clearly dysfunctional. Regarding diagnosis, patients with Schizophrenia and previous history of suicidal behaviour showed a poorer performance in executive function. Patients with current symptoms of an Affective Disorder and a previous history of suicidal attempt had poorer performance in attention and executive function. Similarly, euthymic affective patients with history of suicidal behaviour had worse decision-making, attention and executive function performance compared to euthymic non-attempters.

The number of papers included in this review is limited to the few studies using non-attempter clinically-matched control group and therefore results regarding diagnosis, symptomatology and time of the attempt are modest and contradictory.

Patients who have attempted suicide have a poorer neuropsychological functioning than non-attempters with a similar psychiatric disorder in attention and executive function. These alterations increase vulnerability for suicide.