This textbook presents an innovative educational and training protocol for treating mental health patients in primary care: the Multimodal Brief Systemic Training (MBSTP). Blending theory with practice, this manual offers a rigorous, versatile, and integrative approach, grounded in research, that can be easily adopted by primary care professionals—including general practitioners, nurses, social workers, and psychologists. It is not only invaluable for psychotherapy students but also serves as a vital resource for physicians and other non-mental health professionals seeking to support individuals facing cancer, chronic pain, palliative care, and other conditions that intertwine emotional, mental, and behavioural challenges within their close relational systems. The MBSTP is a compelling alternative to existing evidence-based training programs, which often centre on Cognitive Behavioural Therapy. Designed as a continuing education course led by a team of mental health specialists, this training provides a structured pathway for professional development. This book will help to reignite practitioners' interest in systemic thinking, encouraging them to revisit its significance in their work, or, for those new to the concept, to embrace it as a crucial aspect of their professional growth and contribute meaningfully to their evolution in the field.