Stress is an adaptive response that has developed throughout evolution, and is associated with multiple changes in the biochemistry, histology and physiology of an organism. As stress may induce or contribute to multiple neuropsychiatric disorders, the rigorous investigation of the neural substrates of stress has become a critical endeavour of contemporary biomedical science. This book explores the physiological responses that researchers have attempted to assess in stress-evoked behavioural changes, using both human and animal "experimental" models in clinical and non-clinical research. Though all aspects of the field have their challenges, animal experimental research of stress is a particularly difficult but meaningful task. This book provides succinct and relevant summaries of progress in the area of assessing stress response and the conditions contributing to it.