How to challenge negative thoughts: catch it, check it, change it
2 min read · 7 steps · Updated 3 October 2026
Catch the thought: notice when you are expecting the worst, seeing only the bad, thinking in all or nothing, or blaming yourself for everything. Check it: ask how likely it really is, what the evidence is, and what you would say to a friend who thought this. Change it: put a fairer, more balanced thought in its place.
How we feel depends less on what happens than on what we tell ourselves about it. Some thoughts are automatic, harsh and simply inaccurate, and we believe them because they are ours. Catch it, check it, change it is the core technique of cognitive behavioural therapy, as taught in the self-help programme of the UK's National Health Service. It is a skill, and it gets easier with practice.
This is general information, not medical advice. If worry or low mood lasts for more than two weeks or affects your daily life, speak to a doctor.
Step by step
Learn the four patterns
Expecting the worst outcome from any situation. Ignoring the good sides and seeing only the bad. Seeing things as all good or all bad, with nothing in between. Seeing yourself as the only cause when something goes wrong.
Catch it
When your mood drops suddenly, stop and ask: what just went through my mind? Write the thought down word for word, for example: I made a mistake in the meeting, so everyone thinks I am useless. Note which of the four patterns it fits.
Check it: how likely is it?
Step back and look at the thought as a claim, not a fact. How likely is the outcome you fear? Has it happened before? What actually happened last time?
Check it: what is the evidence?
Write down the evidence for the thought and the evidence against it. Are there other explanations? In the example: one mistake, in a meeting where you also made three useful points, and nobody said anything.
Check it: what would you tell a friend?
If a friend told you this thought about themselves, what would you say? Most people are far fairer to a friend than to themselves. Say the same to yourself.
Change it
Write a new thought that fits the evidence. It does not have to be cheerful, only accurate: I made one mistake. It was noticed and corrected. It says nothing about my worth, and next time I will check the figure first.
Keep a thought record
For a few weeks, write it down each time: the situation, the feeling and how strong it was, the thought, the evidence for and against, the balanced thought, and how you feel afterwards. On paper the technique works much better than in your head.
Good to know
If a thought cannot be changed because it is partly true, you can still change what you do about it, and how much room you give it.
Do not argue with yourself in the middle of the night. Write the thought down and check it in daylight.
This is a self-help tool. If dark thoughts are constant, or you feel hopeless, see a doctor. The same technique is taught in therapy with someone who guides you.
Related: how to build self-confidence, how to stop comparing yourself to others and how to stop worrying all day.
If you are in immediate danger or thinking of harming yourself, call the emergency number now (112 in the EU). In Germany the Telefonseelsorge is free and open around the clock on 0800 111 0 111.
In short: Catch the thought and its pattern, check it with likelihood, evidence and what you would tell a friend, change it into a balanced one. Write it down in a thought record.
- NHS Every Mind Matters: Reframing unhelpful thoughts
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