This project arises from the need to better understand the psychobiological factors that increase vulnerability to risk behaviours in a social context marked by rising anxiety, depression and other negative affective states following the pandemic. It focuses on the role of negative affectivity, understood as a stable tendency to experience negative emotions, and its relationship with risk behaviours relevant to mental health, such as drug use or suicidal behaviour. In particular, the project examines how acute stress modulates decision-making in individuals with negative affectivity, with the aim of identifying behavioural risk profiles. To this end, it combines an experimental stress induction paradigm using the Trier Social Stress Test with a risk decision-making task, the Iowa Gambling Task, also incorporating physiological measures such as vagal tone, electrodermal activity and cortisol. The project pays special attention to the role of gender, given its influence on the stress response and decision-making processes, and aims to provide useful knowledge for understanding the neurobiological mechanisms involved and guiding future preventive and therapeutic strategies.