Aaron T. Beck was an American psychiatrist, widely recognized as the father of cognitive therapy. Born in 1921, he developed this therapeutic approach in the 1960s to help patients identify and change negative thought patterns that contribute to emotional distress. His work has significantly influenced the treatment of various mental health disorders, including depression and anxiety. Beck also created the Beck Depression Inventory, a widely used questionnaire that assesses the severity of depression. Throughout his career, he published numerous books and articles, contributing to the understanding of cognitive behavioral therapy (CBT) and its effectiveness in mental health treatment.