The way that we think about things has an impact on our mood, anxiety and stress levels. Many of these thoughts occur outside of our control, and can be negative or unhelpful. It is therefore important to remember that they are just thoughts, without any real basis, and are not necessarily facts. Even though we may believe a lot of our unhelpful thoughts when we are feeling low, anxious or stressed, it is good to remember that they should be questioned as they are often based on wrong assumptions.
So, to challenge thoughts, you can ask yourself the following questions:
What evidence for, or in favour, of this thought is there?
What evidence against this thought is there?
Is this thought a fact or an opinion?
Is this thought helpful, is it productive?
What would a friend tell me about this thought?
What would I tell a friend who was having this thought?
Will this matter a month from now? Six months from now? A year from now? Five years from now?
Adapted from: http://www.moodjuice.scot.nhs.uk/challengingthoughts.asp