Because cognitive behavioural therapy is designed to help people think about the problems they face and to adjust their behaviours accordingly, it can be used successfully in the treatment of anxiety. When people start to feel anxious, it is usually not something that comes out of the blue. Rather, there are stimuli that lead to a certain habituated thought process that, in turn, lead to excessive amounts of worry and concern. The idea is to use the therapy to address the thought processes which have become such an unhelpful habit. Therefore, most therapists will expose their patients to the sort of things they become anxious over while encouraging them to remain mindful of their internal thought processes in reaction to them. In theory, over time, more mental control can be gained, which will dissipate feelings of anxiety. In this way, CBT can be deployed as a way of dealing with both irrational fears. Indeed, it can help people who have suffered severe trauma, which may have resulted in conditions like post-traumatic stress disorder.