Dr Albert Ellis was an icon in the world of psychology and psychotherapy. He credited Adler for being an influence in his development of rational emotive behavior therapy (REBT), the approach that heralded the cognitive revolution in psychotherapy. His work influenced the rise of cognitive-behavioral approaches that followed his, including CBT, DBT, ACT, Positive Psychology, and others. According to a survey in the 1980s of professional psychologists, Ellis was ranked as the most influential psychotherapist, with Carl Rogers and Sigmund Freud following, and in 2005 he was named as one of the Icons of the twentieth century.