Introduction. Suicidal behaviour is a major public-health concern shaped by interacting psychological, interpersonal, social, cultural, and existential factors. Explanations based solely on psychiatric diagnosis or a single adverse event fail to capture the pathways from distress to suicidal ideation and from ideation to action.Aim. This narrative review synthesises selected psychological, psychodynamic, existential, and sociological approaches to suicidal behaviour, identifies clinically relevant protective factors, and examines the bioethical tension between suicide prevention and socially legitimised forms of assisted dying.Materials and methods. A focused narrative search of peer-reviewed literature and citation contexts was conducted and updated in July 2026. Searches addressed the main psychological, interpersonal, social, protective, and end-of-life concepts considered in the review. Systematic reviews, meta-analyses, recent empirical studies, official statistics, and seminal theoretical works were prioritised. Evidence was synthesised thematically without quantitative pooling.Results. Psychological pain, hopelessness, burdensomeness, thwarted belongingness, defeat, and entrapment are important but non-specific correlates of suicidal ideation. Additional volitional factors influence progression to action. Narcissistic vulnerability may increase risk when shame, humiliation, affective dysregulation, and interpersonal rupture converge. Meaning, social support, treatment, physical activity, and some forms of spiritual engagement may be protective, but their effects are context-dependent. Assisted-dying practices must be distinguished by agency, intention, capacity, clinical indication, and safeguards.Conclusions. Effective prevention requires coordinated clinical, relational, and population-level responses that reduce psychological pain, restore connection and realistic hope, and strengthen accessible mental-health, social, and palliative care. End-of-life policy should preserve conceptual clarity and monitor the effects of changing eligibility criteria without replacing empirical scrutiny with either alarmist or dismissive rhetoric.