New ways of understanding the brain   its nature, its capacities, its function, and its dysfunction   hold great promise for human wellbeing. Novel therapeutics spurred by this understanding have important roles addressing many clinical conditions, including Alzheimer Disease, depression, addiction, and obsessive-compulsive disorder. This unique title explores a wide range of groundbreaking sciences and clinical practices for brain-based conditions, including deep brain stimulation, optogenetics, technology-delivered therapies, predictive testing, and new clinical uses of ketamine, cannabis, and other psychoactive substances.