The functional capacity of the brain structures that are involved in the integrated circuits that mediate mood and emotion determines stress resilience, and is in turn reflected in an individual's psychological make-up. More adaptive functioning of fear, reward, emotion regulation or social-behaviour circuits is thought to underlie a resilient individual's capacity to face fears, experience positive emotions, search for positive ways to reframe stressful events and derive benefit from supportive friendships. Thus, resilience is an active process, not just the absence of pathology, and it can be promoted by enhancing protective factors. Much more study is required to achieve a deeper understanding of stress resistance — in particular, research in resilient individuals who have recovered from traumatic experiences.