Clinical and neurocognitive markers of suicidality in young adults

Background: Suicide represents a leading cause of death in young people, yet relatively little is known regarding the neurobiological sequelae of preceding suicidal thoughts and behaviours. Although some studies have reported cognitive deficits associated with suicidality, very few studies have been undertaken in young people, especially from non-clinical contexts. Aims: To quantify cognitive deficits associated with suicidality using a representative sample of young people, recruited from the general community using media advertisements. Method: 304 adults (18-29 years) undertook the Mini-International Neuropsychiatric Inventory (MINI) suicidality module, along with Cambridge Gamble and Stop-Signal tasks. Suicidality was defined as non-zero MINI scores (broad definition) and a past history of suicide attempt(s) (narrow definition). Clinical features and cognitive performance were compared between those with and those without suicidality, using analysis of variance/chi-square; findings were further explored using linear regression. Results: Suicidality was relatively common (broad definition: 14.8%; narrow definition: 5.3%) in young people and was associated with impaired decision-making on the Cambridge Gamble task (p < 0.05, Bonferroni corrected at the analysis level of each suicidality definition). Linear regression demonstrated that decision-making performance was associated with a significant incremental benefit with respect to predicting suicidality, over and above the utility of demographic and clinical variables considered (p < 0.05 uncorrected). Conclusions: Impaired decision-making exists in young people with suicidality, and may thereby predispose towards a range of suicidal thoughts and behaviours. Further work is needed to clarify the chain of progression from such thoughts/behaviours, which are relatively common, through to actual suicide, which is not.