Cognitive-behaviour therapy (CBT) was developed in the 1960's. Other terms often used for it are cognitive behavioural therapy and cognitive therapy. One of the main developers of CBT was (and still is) Dr Aaron Beck, an American Psychiatrist. Trained in psychiatry and psychoanalysis he conducted some research on depression and found that the psychotherapeutic treatments and the underlying theories at the time were not helpful to people who are depressed. He and many other people who have contributed to CBT over the years shaped a therapy that focuses on how the way we think about a situation interacts with our emotions, our behaviour and our physical experiences.
For example someone who thinks that all dogs are always aggressive, unpredictable and dangerous will exprience anxiety when seeing a dog. He will avoid dogs as much as possible and have a fear reaction when actually encountering one. If that person decides to allow himself to find out more about dogs he will learn and experience that they are not unpredictable and that his previous thought that all dogs are always aggressive and dangerous is an unrealistic generalisation and catastrophisation. As a consequence the anxiety will go down. The aim however is not to simply 'think positive' and in this example to think that all dogs are always sweethearts. The aim is to see situations more realistically, i.e. in the dog-example that the great majority of dogs are friendly and that the behaviour of those who are not is predictable and preceded by certain signs and behaviours.
Equally, in low mood the aim is not to make you think 'Only wonderful things happen and everybody loves me' but to challenge the negative thoughts that go together with low mood and may say 'I have not achieved anything, only bad things happen to me, and noone really cares about me'. A realistic middle-ground may be that some good and some bad things happen, that some people don't like you but there are also many you can really rely on and that you did not succeed in every single thing (who does?) but that you are a valuable person. In order to change the unhelpful way of thinking, CBT uses many different techniques, such as practising to recognise the negative thoughts, challenge them, take new perspectives as well as trying and practising new behaviours. As you can see CBT is an active treatment and self-help tasks are usually part of the treatment programme to bring about greater and faster success. Although the main focus of CBT is on the current situation and on the changes you can make to ensure a better future, CBT may also include looking at experiences that may have contributed to e.g. negative thoughts about yourself or situations or to unhelpful patterns of behaviour. However, the aim is always to only look at the past in order to create a better present and future.
Right from its development emphasis was placed in CBT to measure if it is actually helpful to people. Clearly, it only makes sense for someone going through a rough patch to invest time and effort into a therapy if it actually has a proven effectiveness. This approach also allowed CBT to develop and improve continually. CBT also aims to constantly include new insights from research into how our human emotional, cognitive and memory systems work.
While overall effectiveness for a therapy can only be measured in big studies, CBT also includes formulating clear therapy goals and using feed-back, frequent discussion of progress and questionnaires in individual therapy to ensure that you are actually benefitting from it as much as possible.
In terms of big clinical studies CBT has been demonstrated in over 400 studies to be effective for a wide variety of problems, including depression, anxiety, eating disorders, substance abuse, chronic pain, trauma and even psychotic disorders. There is also good evidence for CBT's effectiveness in preventing relapse after treatment has ended as the skills learned during therapy continue to be helpful. In this important respect it compares especially favourably to medication therapy since the relapse rate after stopping medication is unfortunately very high in many problems. This is why it has been recommended in the UK by the National Institute for Health and Clinical Excellence but also by many other medical organisations worldwide as a treatment of choice for a great number of mental health difficulties. For some mental health problems CBT can also successfully be combined with medication therapy.