Cognitive distortions are exaggerated and irrational thoughts, identified in cognitive therapy and its variants, which in theory perpetuate some psychological disorders. The theory of cognitive distortions was presented by David Burns in The Feeling Good Handbook in 1989, after studying under Aaron T. Beck. Eliminating these distortions and negative thoughts is said to improve mood and discourage maladies such as depression and chronic anxiety. The process of learning to refute these distortions is called "cognitive restructuring".