Glucocorticoids are hormones that the body releases into the bloodstream in response to stress, protecting our bodies in the short term against the damaging effects of stress. Chronic oversecretion of these stress hormones can lead to various mental health disorders such as anxiety and depression. Humans show extreme differences in how they adapt or succumb to the pathological effects of stress. Sex steroids play a critical role in individual and gender-based differences in stress-induced pathology, but the basis for this in the central nervous system is not understood. Independent studies in rodents and humans show that testosterone can regulate the magnitude of the glucocorticoid and behavioural responses to stress. With this data, Dr. Victor Viau is working to determine how testosterone operates on stress-related pathways in the brain, from a physiological and chemical perspective. He is investigating how early-life exposure to testosterone determines the brain’s response to stress during adulthood, and providing insights about the underlying factors that allow the individual to manage stress in different ways. Viau’s research program is unique as it aims to determine how, where, and when stress and testosterone interact in the nervous system and at the hormonal and behavioural levels. The research will ultimately provide a fundamental framework for understanding why some individuals succumb to the psychopathological effects of stress and others persevere in the face of it.