The document provides an overview of cognitive behavioural therapy (CBT), including its historical background and theoretical foundations. CBT evolved from behavioural and cognitive psychology theories. It integrates cognitive and behavioural techniques to change dysfunctional thoughts and behaviors. The core principles of CBT are that maladaptive thoughts cause emotional and behavioral problems, and that modifying irrational beliefs through cognitive and behavioral techniques can improve symptoms. CBT involves identifying negative automatic thoughts, cognitive distortions, and core beliefs; and using techniques like cognitive restructuring and behavioral experiments to change maladaptive patterns.