Given the complexity of scientific developments inside and outside the psychoanalytic field, traditional definitions of basic psychoanalytic notions are no longer sufficiently comprehensive. We need conceptualizations that encompass new clinical phenomena observed in present-day patients and that take into account contributions inside, outside, and on the boundaries of our practice. This book discusses theoretical concepts which explain current clinical expressions that are as ineffable as they are commonplace. Our patients resort to these expressions when they feel distressed by their perception of themselves as unreal, empty, fragile, non-existent, non-desiring, doubtful about their identity, beset by feelings of futility and apathy, and emotionally numb. The book aims at contrasting the ideas of Winnicott and Kohut, which are connected with a clinical practice that sees each patient as unique and are moreover in direct contact with empirical facts, and applies them to the benefit of complex patients. These ideas facilitate the expansion of paths in both the theory and the practice of our profession. Uniquely contrasting the works of two seminal thinkers with a Latin American perspective, Winnicott and Kohut on Intersubjectivity and Complex Disorders will be invaluable to clinicians and psychoanalysts.