This chapter contains section titled: Overview The Cognitive Model Evidence for the Cognitive Model What is the evidence regarding the existence of negative distortions in the thoughts of depressed individuals? Are these cognitive distortions related to environmental stimuli, and do these distortions have an impact on emotion and behaviour? What is the evidence that there are different levels of cognition, and that the presence of the different types of cognitions is important to the experience of depression? What is the evidence that early life experiences influence the development of negative cognitive structures? Conclusion References Overview The Cognitive Model Evidence for the Cognitive Model What is the evidence regarding the existence of negative distortions in the thoughts of depressed individuals? Are these cognitive distortions related to environmental stimuli, and do these distortions have an impact on emotion and behaviour? What is the evidence that there are different levels of cognition, and that the presence of the different types of cognitions is important to the experience of depression? What is the evidence that early life experiences influence the development of negative cognitive structures? Conclusion References