Compare two explanations for your difficulties — the threat-based explanation (Theory A) and the anxiety-based explanation (Theory B) — to guide treatment focus.
Theory A vs Theory B
PreviewWe all use explanations to make sense of what happens. Sometimes a frightening explanation feels true, but an alternative one fits the facts at least as well - and is far less distressing. This worksheet sets your current explanation (Theory A) alongside an alternative (Theory B) so you can weigh them up.
What is the problem or worry you want to understand?
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This is the frightening explanation: that the danger is real.
Theory A: 'The problem is that...'
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Right now, how much do you believe Theory A? (0-100%)
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What evidence seems to support Theory A?
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If Theory A is true, what do you have to do to cope or stay safe?
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If you keep living as if Theory A is true, what will it mean for you and your future? What is it costing you?
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This is the less frightening alternative: that the problem is the worry itself, not the threat.
Theory B: 'An alternative is that the problem is...'
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Right now, how much do you believe Theory B? (0-100%)
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What evidence fits Theory B?
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If Theory B is true, what would you do differently?
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Step back and compare the two.
Which theory best fits ALL the evidence, taken together?
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Which theory is more helpful to act on right now, and why?
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What would it look like to act as if Theory B were true for a set period - say the next week or two?
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The fairest way to tell the theories apart is to act on Theory B and see what happens. Acting on Theory B means easing off worry-driven checking and reassurance - it does not mean ignoring your body. If you have a new or changed physical symptom you have not had looked at, it is sensible to get it checked once in the normal way, and then practise letting the worry be.
Your experiment: how will you act as if Theory B is true this week?
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After testing - what did you notice?
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Now, how much do you believe Theory A? (0-100%)
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And how much do you believe Theory B? (0-100%)
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This is a read-only preview. Sign up to assign it and let clients complete it on any device.
‘Theory A vs Theory B’ is an interactive cognitive behavioural therapy (CBT) worksheet, most often used in CBT for health anxiety. It is also commonly drawn on when working with obsessive-compulsive disorder (OCD).
It is designed to be used within therapy rather than as a standalone self-help tool: a therapist introduces it, works through it collaboratively, and helps make sense of what it surfaces. You can preview the full worksheet above, then assign it digitally for clients to complete between sessions on any device — or download it as a print-ready PDF.
Most people work through it in around 25 minutes. It moves through five short steps:
Completed on the Formulate platform, your client's answers are saved automatically and shared straight back to you, so you can review them before the next session rather than waiting for a paper copy to come back.
In common with other CBT methods, ‘Theory A vs Theory B’ works by noticing and re-evaluating unhelpful automatic thoughts (cognitive restructuring). The aim is not positive thinking but a clearer, shared understanding of what keeps a difficulty going — and practical, testable ways to change it.
Because it is a CBT tool it stays focused on the here-and-now links between thoughts, feelings, the body and behaviour, and it works best as one part of a wider course of therapy rather than as advice or a diagnosis.
This worksheet is grounded in established cognitive behavioural therapy theory and practice. Key sources include:
Formulate provides educational CBT resources for use with a qualified therapist. They are not a substitute for professional assessment, diagnosis, or crisis care.
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