This volume builds on the idea, developed by psychiatrist Harry Stack Sullivan in the first half of the 20th century, that the social experiences between people, particularly those close to them, determine their sense of self and guide their behavior. The authors seek to update this theory with an eye toward clinical applications for 21st-century conditions. Examples include treatment of individuals with LGBTQIA+ identities, changing views of so-called mental disorders, and changing household environments. The theory and its associated "talk" therapies are counters to the prevalent psychiatric perspectives that the authors claim are wrongly couched in short-term drug fixes and guided by pressures from insurance companies rather than by evidence of long-term changes in behavioral patterns. Related to classical psychoanalytic thought, the theory builds on concepts of developmental eras and particularly the formative experiences one has during childhood. Considering rapidly changing notions of adolescence in the 21st century, the authors provide intriguing insights into the influence of the "juvenile era" and preadolescence on personality and behavior. Recommended. Advanced undergraduates through faculty; professionals.