Longitudinal associations between executive function impairments and suicide risk in patients with major depressive disorder: A 1-year follow-up study

Abstract

Impaired executive function (EF) is a key feature of patients with major depressive disorder (MDD) that several studies have linked to suicidal ideation and suicide attempts. This is the first longitudinal study to examine the association between impaired EF and suicide risk in adult patients with MDD. Longitudinal prospective study with 3 assessment points: baseline, 6 and 12 months. The Columbia-Suicide Severity Rating Scale (C-SSRS) was used to assess suicidality. The Cambridge Neuropsychological Test Automated Battery (CANTAB) was used to assess EF. The association between EF impairments and suicidality was analyzed using mixed-effects models. Out of 167 eligible outpatients, 104 were included in the study. Of these, 72 were re-evaluated at 6 months and 60 at 12 months, obtaining 225 complete observations of the EF. Impaired decision-making and risk-taking behavior were associated with suicidal ideation. Difficulty in impulse control was related to suicidal ideation and to greater severity of suicidal ideation. Impaired spatial planning and working memory was linked to suicide attempts. Our results add to previous literature that the association between EF impairments and suicidality is maintained over the long term, supporting it as a longitudinal risk factor and a possible neurocognitive marker of suicide in patients with MDD.