Sigmund Freud proposed psychoanalysis which focuses on the unconscious mind and repressed desires from childhood influencing behavior. His psychosexual stages, defense mechanisms, and structure of mind including the id, ego and superego have contributed to understanding human behavior but lack scientific evidence and may not apply to all cultures.
Alfred Adler's individual psychology focuses on how life experiences shape one's views and inferiority complexes. His ideas on birth order and striving for perfection provide insights although not all are universally applicable.
Carl Rogers' humanistic theory of self-actualization emphasizes fulfilling needs and developing one's identity through positive regard. His client-centered therapy has been successful although it does not consider unconscious influences and lacks scientific proof