Cognitive behavioural therapy is the favoured alternative to drugs as a treatment for common mental health problems. It is based on the principle that certain types of thoughts that we have about ourselves — at its simplest, whether we think we are loved, wanted, despised or boring — have a major effect on the way we perceive the world. If we feel unloved, the world will appear to be unloving, and then every moment of every day our sense of being unloved is confirmed. That, after all, is what depression is all about. These types of thoughts are called "automatic thoughts" because they operate on the margins of our consciousness as a continual sort of internal monologue. If these thoughts can be identified and brought out into the open, then the state of mind they sustain, whether anxiety, depression, or any of the other neuroses, can begin to be resolved. This type of therapy is called "cognitive", because it is primarily about changing our thoughts about ourselves, the world and the future.
Cognitive therapy is linked to a companion branch of therapy known as "behavioural therapy", which aims to deal not with the underlying causes of symptoms such as depression and anxiety but with the symptoms themselves. When practised together as cognitive behavioural therapy, the two approaches have been found to be highly effective in the treatment of depression and anxiety disorders, with the added major benefit that people successfully treated with CBT are less likely to experience later recurrence of their condition than those successfully treated with other forms of therapy.