Cortisol reactivity and suicidal behaviour: the role of hypothalamic-pituitary-adrenal axis responses to stress in suicide

Abstract

Background. Suicide is a major cause of death worldwide. The causes of suicidal behaviour are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. Recent evidence has indicated that cortisol reactivity to stress may be associated with suicidal behaviour. The current study investigated whether cortisol reactivity to laboratory stress differed between individuals who had previously made a suicide attempt compared to suicide ideators and controls. Methods: One hundred and sixty participants were recruited to a previous attempt, suicidal ideation and a control. Participants completed background questionnaires before completing a stress task known as the Maastricht Acute Stress Test (MAST). Cortisol, cytokines, blood pressure and heart rate were assessed throughout. Measures of suicide ideation and attempt were measured at 1 month and 6 month follow-up. Findings: Participants who had made a previous suicide attempt exhibited significantly lower levels of cortisol in response to the MAST compared to participants in the ideator and control groups. Moreover, participants who made an attempt within the past year exhibited significantly lower levels of cortisol compared to participants with a lifetime history of attempt. In addition, lower levels of cortisol in response to the MAST were associated with higher levels of suicidal ideation at 1-month follow-up. Conclusion: These findings confirm that HPA axis activity is associated with suicidal behaviour. Moreover, cortisol reactivity may represent an important biomarker of a trait-diathesis following serious stressful and traumatic events and it may be an additional useful predictor of suicide risk.