Cognitive-behavioural therapy is a method of treating emotional and behavioural disorders that is scientifically proven to be effective. It is used to reduce symptoms and difficulties in adults, children and adolescents experiencing mood and anxiety disorders, including obsessive-compulsive disorder, PTSD, tics, eating disorders, but also impulsive and aggressive behaviour.

Cognitive-behavioural therapy effectively combines methods involving behaviour change and thought modification.

At the heart of cognitive-behavioural therapy is the theory that by changing maladaptive (erroneous, dysfunctional) thinking, mood and behavioural change can be achieved. The therapist uses CBT techniques to help the patient/client revise their own thinking patterns and their own beliefs and replace "thinking errors" with more realistic and effective thoughts. This reduces discomfort and curbs self-limiting behaviour as a result. Cognitive-behavioural therapy allows replacing unhelpful ways of coping, thinking, feeling, and behaving with more useful, more adaptive ones. CBT assumes that the dysfunctional ways of reacting with thoughts, feelings and behaviours have been learnt during an individual's development, and therefore it is possible to unlearn them (under favourable circumstances) or learn new ways of functioning. Overall, everyone can learn to think about themselves, the world, other people in a way that is more conducive to healthy daily functioning.