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Aaron Beck founded cognitive behavioral therapy, building a treatment for depression and anxiety around the idea that changing a patient's distorted thought patterns could relieve the disorder itself — a departure from the psychoanalytic orthodoxy he had trained in. His Beck Depression Inventory became one of the most widely used tools for measuring depression's severity, and CBT itself became a standard treatment worldwide. He published more than 600 papers and 25 books, and in 1994 founded the Beck Institute for Cognitive Behavior Therapy with his daughter, psychologist Judith Beck.