Many studies have provided important information regarding the anatomy, development and functional organization of the 5-HT system and the alterations in this system that are present within the brain of the suicidal patient. There is also a growing interest in genetic factors associated with suicide, since these may lead to the emergence of personality traits that prove to be long-term predictors of suicidal behaviour. This review will focus on presenting the scientific literature on the role of the serotonergic system in suicidal behaviour as well as dysfunctional attitudes and personality traits associated with the suicidal patient. The association of the serotonin transporter gene, the 5-HT2 receptors and its metabolite 5-hydroxyindoleacetic acid with suicidal behaviour and animal models that may capture the complexity of suicidal behaviour will be discussed. Finally, the relationship between neurobiological models and psychotherapeutic interventions for suicide prevention will be considered with a focus on Schema Therapy (an approach that has shown particular promise in the treatment of suicidal individuals with personality disorders), aiming to invite the reader to integrate some aspects of the neurobiology of human suicidal behaviour into a model of suicide that can be used in a clinical encounter.