The intolerance of uncertainty model helps explain why not knowing can feel so difficult and why worry may become the mind’s way of trying to find an answer.
Imagine sending an important email and not hearing back. Nothing has necessarily gone wrong, but the gap in information can quickly fill with possible explanations. You may start wondering whether the message was misunderstood, whether you made a mistake or whether you should send another email.
For someone who finds uncertainty particularly difficult, the unanswered question can start to feel like something that needs to be solved. Worry, checking and mental preparation may follow, even though no new information is available.
Our guide to worry and generalised anxiety disorder explains the wider worry cycle. Here, we look more closely at why uncertainty itself can become such an important part of that pattern.
Uncertainty is part of everyday life, but not knowing can feel especially difficult when the mind treats uncertainty as threatening.
Worry may feel useful because it creates a sense of preparation, responsibility or control.
Checking, reassurance and over-preparing can briefly reduce anxiety without resolving the underlying uncertainty.
The subject of worry may change while the same need to know or prepare stays underneath.
Some problems have a practical action available, while other questions simply cannot be answered yet.
CBT looks at what uncertainty means to the person and what responses may be keeping the worry cycle active.
The model was developed to help explain some of the processes involved in persistent worry and generalised anxiety disorder.
Early research by J Dugas and colleagues identified four closely related areas: intolerance of uncertainty, beliefs about worry, negative problem orientation and cognitive avoidance. Intolerance of uncertainty appeared to play a particularly important role in distinguishing the people with GAD in that original study.
In everyday language, the model helps explain what can happen when not knowing begins to feel difficult enough that the mind repeatedly tries to remove the uncertainty.
| Part of the model | What it may look like |
| Intolerance of uncertainty | Not knowing feels difficult to leave unresolved |
| Beliefs about worry | Worry feels useful, responsible or protective |
| Negative problem orientation | Problems can feel threatening or difficult to manage |
| Cognitive avoidance | Worry keeps attention focused on possible future problems |
The model was originally developed around worry and GAD. More recent research has shown that intolerance of uncertainty can also appear across other mental health difficulties. A 2026 review by Dugas, Koerner and Freeston describes it as a broader process while still recognising its particularly strong history within worry and GAD research.
For this article, we are focusing specifically on how it can help make sense of persistent worry.
Sometimes the hardest part of a situation is waiting to find out what will happen.
Someone waiting for an important decision may even feel that they would rather receive a disappointing answer than continue not knowing. Once the outcome is known, there is at least something definite to respond to.
Uncertainty offers no such answer.
The mind may therefore keep returning to the situation, looking for clues or trying to predict what will happen next.
This does not necessarily mean the person believes something bad will happen. The difficulty may be that they cannot confidently rule it out.
Persistent worry often moves between areas of life.
One day it may focus on work. Another day it may be money, family, health or an upcoming decision.
The details change, but the underlying process may be similar.
Something is uncertain; the uncertainty feels difficult to leave alone, and worry begins trying to create an answer.
This is why CBT often looks beyond the topic of each individual worry and towards the process connecting them.
Worry often begins with something unresolved.
It might be an email without a reply, an upcoming meeting, a decision that has not been made or simply not knowing how something will turn out.
For many people, that uncertainty comes and goes without taking up much mental space. When uncertainty feels harder to tolerate, the mind may stay focused on it.
When there is missing information, worry can begin generating possible explanations.
If someone has not replied to an email, you may start reviewing what you wrote, considering whether it sounded wrong or wondering whether the lack of response means something negative.
More possibilities can appear the longer you think.
The difficulty is that thinking does not necessarily bring you any closer to knowing what has actually happened.
The uncertainty remains.
Thinking through several outcomes may seem sensible.
You may feel better prepared if you have already imagined what could go wrong and decided what you would do.
This can make worry difficult to stop because stopping may feel as though you are lowering your guard.
The worry is uncomfortable, but part of you may still believe it is helping.
Worry is often followed by attempts to find more certainty.
You may check your inbox again, reread the message, ask someone else what they think or mentally review the situation from several angles.
Sometimes this settles the anxiety briefly.
The problem is that the unanswered question is still unanswered. When the doubt returns, another check or another round of thinking may feel necessary.
The intolerance of uncertainty model helps explain why this short-term relief can become part of a repeated worry pattern rather than bringing lasting resolution.
It can seem strange that someone continues worrying when worry is exhausting.
One reason is that worry may have started to feel as though it serves an important purpose.
Our article on positive beliefs about worry explores this pattern in more detail.
Thinking ahead can create the sense that you are getting ready for possible problems.
If you have considered several outcomes, you may believe you will be less surprised if something difficult happens.
This can make relaxing feel risky. Worry may begin to seem like part of being prepared.
For some people, worry is closely connected with responsibility.
If something matters, worrying about it can feel like evidence that you care.
Not worrying may therefore feel careless, particularly when the concern involves family, work or an important decision.
Uncertainty involves accepting that some information is unavailable.
Worry gives the mind something active to do.
Thinking, reviewing, and planning may therefore feel more manageable than simply waiting, even when none of those processes can change the outcome.
This can create a sense of control without creating genuine certainty.
Imagine you send an important proposal by email.
You expect a reply later that day, but none arrives.
At first, you simply notice that you are waiting. As more time passes, the lack of response starts to feel more significant.
The pattern might develop like this:
| What happens | How the worry develops |
| Important email is sent | The outcome is now uncertain |
| No reply arrives | Not knowing starts to feel uncomfortable |
| Worry increases | Possible negative explanations appear |
| Checking begins | Inbox and sent message are reviewed |
| Brief relief | Checking creates a temporary sense of action |
| No new information appears | Uncertainty remains and worry returns |
Nothing in the situation has confirmed that the proposal has been rejected or that something went wrong.
The problem is that the mind is finding the absence of an answer increasingly difficult to leave unresolved.
Someone may then spend far more time trying to understand the silence than the available information allows.
Worry can feel very similar to problem-solving because both involve thinking about difficulties.
The difference is whether there is a useful action available now.
Imagine you receive a bill with the wrong amount.
There is uncertainty about why the amount is incorrect, but there is also something practical you can do. You can check the bill, contact the provider or gather the information needed to query it.
Thinking can lead to an action.
Once that action is taken, there may be little more you can usefully do until you receive a response.
Waiting for someone to decide whether they accept your proposal is different.
You may have sent all the information they need. There may be no sensible action available until they reply.
Thinking for another hour will not produce information that you do not currently have.
The challenge is no longer solving a practical problem. It is living for a period of time without knowing the outcome.
When uncertainty feels urgent, the mind can treat an unanswered question as though it were a problem that should be solvable through enough thought.
This can lead to repeated planning, reviewing and considering possibilities without reaching a usable next step.
The person may feel mentally busy while remaining in exactly the same uncertain situation.
Recognising this distinction is one way CBT can begin making the worry process clearer.
CBT does not aim to remove uncertainty from life.
That would be impossible. Decisions, relationships, work and everyday plans all involve situations where the outcome cannot be known in advance.
Instead, therapy can look at what happens when uncertainty appears and why the person feels such a strong need to resolve it.
NICE includes CBT among the recommended high-intensity psychological treatments for generalised anxiety disorder when this level of treatment is appropriate.
Therapy may look at situations where not knowing feels particularly difficult.
For one person, this may involve unanswered messages. For another, uncertainty around decisions, work performance or family responsibilities may be more difficult.
The important question is not simply what the topic is, but what not knowing comes to mean.
The person may fear being unprepared, making the wrong choice, missing a problem or not being able to cope if something unexpected happens.
CBT also considers the role worry seems to play.
Does worrying feel like preparation?
Does it feel responsible?
Does the person believe they will be more likely to prevent a mistake if they keep thinking?
Understanding these beliefs matters because worry is harder to change when part of the person still sees it as necessary.
The intolerance of uncertainty CBT approach focuses on the wider pattern rather than giving someone certainty about each individual worry.
Therapy may look at repeated checking, reassurance, over-preparing, delaying decisions or mentally reviewing possibilities. These responses can make sense in the moment because they reduce anxiety or create a feeling of control.
The longer-term question is whether they are helping the person become more able to live with uncertainty or teaching them that every doubt needs an answer.
For people looking for professional support, our GAD and worry therapy service explains how we work with persistent worry using CBT.
We have anonymised the following example for privacy reasons. Identifying details have been changed.
One client came to NOSA because worry around work decisions and unanswered messages was taking up a large part of their day.
When something was unresolved, they spent long periods considering different outcomes, checking messages and asking other people what they thought.
The topics changed, but the feeling that they needed to know what would happen remained similar.
In therapy, we looked at what uncertainty meant to the client and why worry felt necessary.
A repeated pattern became clearer. Worry gave the client a sense of preparation, while checking and asking others for their views reduced anxiety briefly.
We then worked on recognising when there was a practical problem to act on and when the client was trying to create certainty about something that could not yet be known.
Over time, the client became more able to notice uncertainty without immediately trying to resolve it.
Unanswered questions could still trigger worry, but they took up less time and were less likely to lead to repeated checking and mental preparation.
The client became more able to continue with everyday activities while waiting for information to become available.
Uncertainty is unavoidable, but it can become exhausting when every unanswered question feels as though it needs to be resolved before you can move on.
Worry may then feel useful because it creates a sense of preparation, responsibility or control. Checking and reassurance can provide temporary relief, but the original uncertainty often remains.
The intolerance of uncertainty model helps explain why this pattern can become so persistent. CBT can help make the relationship between uncertainty, worry and certainty-seeking clearer, so not knowing does not always have to trigger the same cycle.
The intolerance of uncertainty model is a CBT-informed way of understanding persistent worry and GAD. It looks at how difficulty with not knowing, beliefs about worry, views of problems and patterns of thinking can interact to keep worry active.
It can feel as though unanswered questions are difficult to leave alone. You may feel a strong urge to predict what will happen, prepare for several possibilities, check for more information or ask other people for reassurance.
No. Intolerance of uncertainty is not a separate diagnosis and is not the same thing as anxiety itself. It describes a pattern in how someone responds to uncertainty, and research has linked it with worry, GAD and other mental health difficulties.
Worry can feel like a way of reducing the discomfort of not knowing. It may seem to help you prepare, prevent mistakes or stay in control, even when the thinking itself does not produce any new information.
CBT can help identify what uncertainty means to you, what you believe worry is doing and what happens when you check, seek reassurance or over-prepare. The aim is not to guarantee outcomes, but to change the pattern that makes certainty feel necessary before you can move on.
This page is for general information and education. It is not personalised advice, diagnosis, or a substitute for professional assessment.
NOSA CBT offers evidence-based therapy for OCD, hoarding help, phobias, health anxiety, social anxiety, PTSD, panic disorder, and generalised anxiety disorder. We also provide a specialist OCD clinic, professional CBT supervision training, and CBT training and teaching for mental health professionals.
Get in touch today to find out how we can help.
