What's so good about CBT? Harry Potter author J K Rowling revealed last week that she recovered from serious depression with the help of cognitive behavioural therapy (CBT). This "talking therapy" is now widely used to help people with a range of mental health problems.

What is CBT?
It is a way of discussing how you think about yourself, other people and the world generally (the cognitive part) and how this affects how you feel and what you do (the behaviour bit). It can help you change these things, which can improve your symptoms. Importantly, unlike some other talking treatments, it focuses on "now" and how to improve the way you're currently thinking and feeling, rather than looking back at causes of distress in the past.

Who benefits from it?
The Royal College of Psychiatrists says CBT is "as effective as antidepressants for many types of depression" and "one of the most effective treatments for conditions where anxiety or depression is the main problem". CBT can reportedly help alleviate many conditions, including anxiety, depression, phobias, obsessive compulsive disorder, schizophrenia and bulimia.

How does it work?
It involves breaking your thought patterns and behaviour down into smaller bits to help you understand how they're connected. Broadly speaking, these parts are: a situation, thoughts, emotions, physical feelings and actions.

Give an example.
OK: you've had a bad day, so you go shopping. As you walk down the road, you pass someone you know who, apparently, ignores you. How do you react? There are unhelpful ways, which will tend to make you feel worse, and helpful ways. In the first scenario, your first thought might be: "He ignored me - he obviously doesn't like me." Then negative emotions would follow: feelings of sadness and rejection. They might in turn lead to physical symptoms such as feeling sick and low on energy. All that would influence your behaviour.

You have no actual evidence that the person doesn't like you. But you've ended up feeling bad about yourself and behaving unhelpfully.

What would be the helpful reaction?
You could start by thinking: "He looks a bit wrapped up in himself. I wonder if something's wrong?" You would be concerned, in a friendly way, but have no adverse physical feeling. You would continue your shopping trip, making a mental note to get in touch to make sure your acquaintance was OK. That in turn would give you the chance to correct any lingering misconceptions you might have - and you'd probably feel better about yourself.

And that's it?
Well, it's not quite as simple as that. If you're thinking negatively, your thoughts, emotions and actions can start to reinforce each other, and your behaviour can even prompt new situations that leave you feeling worse. Ultimately, as the Royal College points out, "you can start to believe quite unrealistic (and unpleasant) things about yourself". When we are distressed, it explains, we are more likely to jump to conclusions and interpret things in extreme and unhelpful ways. CBT helps you see the individual parts of the process and change them.

So how is it done?
Either individually or in groups, or even with books or a computer programme. For more information on CBT, start at www.mind.org.uk/information .