Cults have captivated public imagination, gained visibility in the media, and become a popular topic of discourse. While anecdotal and journalistic accounts offer compelling insights, systematic study on the structure, psychological predispositions, and relevance to clinical and legal settings are comparatively scarce. This disparity highlights a crucial need for rigorous scholarly inquiry, moving beyond media portrayals to uncover the foundational mechanisms that sustain and shape these enigmatic groups. Authored by experts in forensic psychiatry and psychology, this book consolidates the extant literature in reviewing the theoretical, sociocultural, clinical, and forensic issues surrounding cultist groups. This text applies evidence-based study to identify group subtypes and explore mediators and moderators that may be relevant in clinical and legal contexts. Authors address issues as they relate to a variety of subpopulations, comorbid mental disorders, mind-altering substances, treatment, and the and legal implications inherent to cults and persuasive leadership. This book may be especially pertinent to mental health professionals and those working in the criminal justice system.