Association between irritability and suicide-related outcomes across the life-course. Systematic review of both community and clinical studies

•Irritability is a promising transdiagnostic predictor for mental health, including suicide-related outcomes.•Community-based studies suggested an association between irritability and suicidality.•Studies in clinical samples reported mixed findings.•Poor evidence linked irritability and suicide mortality.•A major limitation is the heterogeneity in the definition and measurement of irritability.