Psychological and Neurobiological Mechanisms of Suicidal Behaviour: An Integrative Review

Suicide is a complex, multifactorial phenomenon influenced by an interplay of psychological, neurobiological, and socio-environmental factors. Despite its global prevalence and significant public health impact, the underlying mechanisms of suicidal behaviour remain incompletely understood. This review combines established insights into psychological theories and neurobiological factors involved in suicidal behaviours; and highlights potential therapeutic targets. The major psychological models considered include the interpersonal-psychological theory, attachment theory, and cognitive-behavioural theory. Also, their relevance to suicidal ideation and actions were examined. Moreover, neurobiological factors, particularly the roles of serotonin, norepinephrine, dopamine, and neuro-inflammation, were explored. Psychological models elucidate how factors such as perceived burdensomeness, thwarted belongingness, insecure attachment, and maladaptive cognitive patterns contribute to suicide risk. Neurobiological evidence indicates dysregulation in serotonergic, noradrenergic, and dopaminergic systems, as well as neuro-inflammatory processes associated with increased vulnerability. The integrated motivational-volitional (IMV) model further demonstrates how genetic, neurochemical, and psychological factors interact across the trajectory from suicidal ideation to attempts. Due to the significance of certain brain regions in facilitating emotion regulation, decision-making, and stress responses, understanding the dynamic interplay between psychological constructs and neurobiological pathways is essential for developing effective prevention and intervention strategies. Targeting both cognitive-emotional processes and neurochemical imbalances holds promise for reducing suicide risk. Future research should focus on multidimensional approaches to suicide prevention, especially in high-risk populations.