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

BACKGROUND: 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. METHOD: 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. RESULTS: 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. LIMITATIONS: 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. CONCLUSIONS: 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.This work was supported by Carlos III Health Research Institute[grant numbers PI14/02029, PI15/00793, PI15/00789, PI16/01164,PI17/01433 and PI18/01055 (co-financed by the European RegionalDevelopment Fund(FEDER/ERDF)/European Social Fund‘Investing inyour future’ and the Government of the Principality of Asturias PCTI-2018–2022 IDI/2018/235)], Foundation for Health Innovation andResearch (BIOEF); Bioaraba Research Institute; Networking Center forBiomedical Research in Mental Health (CIBERSAM), the BasqueGovernment [grant numbers 2015111024, 2017111104] and theUniversity of the Basque Country [grant number 321212ELBY]. Thepsychiatric research department in Araba University Hospital is sup-portedbytheStanleyResearchFoundation[grantnumber03-RC-003