Mental illness is one of the greatest causes of human suffering, but the reasons we bear this burden, and the nature of these diseases, have remained mysterious. Now, our understanding has reached a tipping point. In Connections, Professor Karl Deisseroth intertwines gripping case studies from his experience as an emergency psychiatry physician, with breakthrough scientific discoveries from astounding new technology. By linking insights from this technology to deeply moving stories of his patients and to our shared evolutionary history, Deisseroth tells a larger story about the origins of human emotion. Addressing some of the most timeless questions about the human condition while illuminating the roots of misunderstood disorders such as depression, psychosis, schizophrenia and sociopathy, Connections transforms the way we understand the brain, and our selves.