Sigmund Freud is considered the founder of psychoanalysis. He developed this therapeutic approach in the late 19th and early 20th centuries, revolutionizing the understanding of the human mind and mental processes. Freud introduced key concepts, such as the unconscious mind, defense mechanisms, and the importance of dreams in understanding behavior and mental health. His methods, including free association and dream analysis, aimed to uncover repressed thoughts and emotions. While many of Freud's theories have been critiqued and evolved over time, his work laid the foundation for modern psychology and psychotherapy, influencing various disciplines and therapeutic practices.