Neurosteroids is a comprehensive textbook authored by Etienne-Emile Baulieu, the discoverer of neurosteroids, along with a team of esteemed scientists and clinical researchers. The book provides a detailed and critical analysis of the role of neurosteroids in various areas, including behavior, stress, memory, depression, anxiety, brain aging, and neurodegenerative diseases. The authors highlight the significance of neurosteroids for brain development and plasticity, explaining their neuromodulatory influences on various receptors and channels in the nervous system. This work serves as a valuable resource for professionals in the fields of neurobiology, psychiatry, neurosurgery, pharmacology, and geriatrics, offering a comprehensive overview of these important bioactive molecules and their potential therapeutic applications, particularly concerning cognitive functions in aging.