Intrusive thoughts: why you have thoughts that frighten you — and why they are not your character

“Am I a bad person if something like that crosses my mind?”

This question often comes in a whisper, towards the end of a session, after the person has hesitated for a long time over whether to say it at all. Behind it there are usually weeks, sometimes months, of quiet checking: will the thought come back, what does it mean, why me. The thought itself may have lasted only a second. It came while washing the dishes, in the car, just before falling asleep — and left behind a feeling as if someone had briefly opened the door to a room you didn’t know you had.

We call such thoughts intrusive thoughts. They are sudden, unwanted thoughts, images or urges that break into awareness uninvited and often stand in sharp contrast to what you hold dear. In this post I will explain why almost all of us have them, why the people who fear them most find them hardest to shake off, and when it is right to seek professional help. I am deliberately not going to list examples that might frighten anyone — we don’t need them in order to understand.

A thought you didn’t order

The brain is not an editor carefully choosing what gets published. It is more like a generator that produces all sorts of things all day long: memories, plans, songs stuck in your head, odd associations and occasionally something that sends a chill through you. Most of it passes by without you noticing. But some of it gets stuck.

An intrusive thought can be entirely ordinary: “What if I didn’t lock the door?” It can be strange: a sudden urge to shout something in a quiet church, or an image of a cup slipping out of your hands. Or it can be the kind that floods you with shame — a thought that runs straight against your values, against the people you love, or against what you believe.

That last part is crucial. The thought frightens you not because it is dangerous, but because it is foreign. Psychology describes such a thought as ego-dystonic: it doesn’t fit with how you see yourself. And because it doesn’t fit, you experience it as an intruder rather than as part of you. You can read more about the concept in the knowledge base under Intrusive thoughts.

Almost all of us have them — research has shown it

In 1978 the psychologists Stanley Rachman and Padmal de Silva carried out a simple but important study. They asked people without any mental health condition whether they ever had unwanted thoughts that upset them. The great majority said yes. What is more, when the researchers compared these thoughts with those of people with obsessive-compulsive disorder, experts often could not tell whose thought was whose. The content was almost the same. The difference lay in how often the thoughts came, how much they distressed people, and what people did with them afterwards.

A good thirty years later, an international team led by Adam Radomsky tested this finding on six continents. The study, published in 2014, included 777 students from thirteen countries. As many as 94 per cent reported having had at least one intrusive thought in the previous three months. Regardless of country, culture or language. The title of the article put it almost poetically: you can run, but you can’t hide.

If you were to remember just one sentence from this post, let it be this: the content of an intrusive thought says nothing about your character. It only says that you have a working brain that sometimes produces something odd.

Why these thoughts in particular

If thoughts arrive at random, why do the most unpleasant ones get stuck? The answer is surprisingly gentle: they get stuck where you care the most.

A person who deeply values honesty will be frightened by a thought about cheating. A young mother who loves her child more than anything will be frightened by the thought that something could happen to the child through her fault. A person of faith will be frightened by a blasphemous thought. The thought doesn’t get stuck because you secretly want it, but because it collides with something that is sacred to you. Where you don’t care, the same thought drifts past like a cloud.

That is why, in therapy, we often read intrusive thoughts the opposite way to how fear reads them: not as proof of what you really are, but as a sign of what matters to you. Fear says: “If you think that, you are dangerous.” It would be more accurate to say: “If it hurts you this much, you care a great deal.”

Why fighting a thought makes it stronger

The most natural response to an unpleasant thought is to try to drive it away. You think of something else, tell yourself “stop”, push it aside. The trouble is that this works poorly — and often has the opposite effect.

In 1987 the social psychologist Daniel Wegner published his famous white bear experiments. He asked people not to think of a white bear for five minutes and to ring a bell whenever the thought crept in anyway. They rang all the time. Even more interesting was what happened next: when they were allowed to think about the bear again, they thought of it more often than people who had never tried to suppress it. Pushing the thought away created a kind of rebound.

With intrusive thoughts this mechanism gains extra power. When you are frightened of a thought, the brain marks it as important. And important things need to be monitored. So without realising it you start looking out for the thought: “Is it back?” And the question alone summons it. In the 1980s the psychologist Paul Salkovskis described how the problem lies not in the thought itself, but in how the person interprets it — as a sign of danger or personal responsibility — and in everything they then do to calm themselves.

Add to this a phenomenon researchers call thought-action fusion: the belief that thinking something is almost as bad as doing it, or that having a thought makes it more likely to happen. The belief is understandable — many people absorbed it in childhood — but it isn’t true. A thought is not an action. Between them lies the whole space of your will, your values and your choices.

If you would like to know how to notice a thought without having to chase it away, I wrote about that in How to notice a thought instead of following it: an introduction to cognitive defusion. The post A single thought can ruin your whole day — if you believe it is about a different kind of thought: anxious predictions that are easy to believe. Intrusive thoughts differ precisely in that you don’t really believe them — and that is why you fear them.

When it is obsessive-compulsive disorder

Intrusive thoughts in themselves are not a disorder. Obsessive-compulsive disorder (OCD) is something different and considerably rarer: an American epidemiological study published in 2010 by Ayelet Meron Ruscio and colleagues estimated that around two to three per cent of people develop it over their lifetime.

In OCD the thoughts (obsessions) come often, are very distressing and are hard to set aside. Around them, actions (compulsions) develop, through which the person tries to reduce the distress or prevent something terrible from happening. Compulsions are not always visible, like hand-washing or checking the cooker. They can be entirely internal: mentally repeating “good” sentences, checking one’s own feelings, endlessly analysing whether one is really like that, or seeking reassurance from loved ones.

We usually speak of a disorder when:

• the thoughts and the actions linked to them take up a lot of your time (professional criteria often mention an hour a day or more),
• they cause severe distress,
• they start shaping your daily life: what you no longer do, where you no longer go, what you no longer touch, who you are no longer alone with,
• you feel you have to do something, or you won’t be able to carry on.

If you recognise yourself in this, it is not a reason for shame but for an assessment by a professional. OCD is well researched and very treatable. A diagnosis can be made by a psychiatrist or a clinical psychologist; I wrote about who is allowed to do what in Who may diagnose, who may prescribe, and who leads the process.

What a conversation about it can sound like

The following excerpt is composed and not about a real person — but it captures something that often happens in a similar form.

“When the thought comes, I tell myself three times in my head that I don’t really mean it. Then there’s peace for a while.”
“How long?”
“Sometimes an hour. Sometimes five minutes.”
“And what happens if you don’t say the sentence?”
“I don’t know. I’ve never tried. I’m too scared it would mean that I do mean it.”
“And what if it only meant that you had left it alone?”

A sentence said three times is a small ritual. It calms you for a moment, so you repeat it. But every ritual tells the brain one more thing: “That thought was dangerous — good thing I neutralised it.” So next time the thought is a little more important. Reassurance works like a loan at a high rate of interest.

What really helps

For intrusive thoughts that grow into a disorder, the most researched approach is exposure and response prevention, carried out within cognitive behavioural therapy. Put simply: gradually, in agreement with the therapist and at their own pace, the person approaches the thoughts and situations they fear and refrains from rituals while doing so. This way the brain learns something it cannot learn while constantly avoiding: that the thought comes and goes without anything happening, and that you can bear the distress. The logic is very similar to what I described in Exposure: why panic has to be approached, not avoided.

A different relationship with your thoughts helps too. Approaches based on mindfulness and acceptance don’t try to convince the thought that it is wrong; they take away its power by not answering it. A thought is an event in your head, not a command and not a revelation.

As a therapist in training in relational family therapy, though, I always look at one more layer. Intrusive thoughts and the fear of them are not born in a vacuum. Many people who fear their own thoughts grew up in an environment where certain feelings were forbidden — anger, envy, the wish to be left alone sometimes. If such feelings were dangerous at home, a child learns that simply feeling them is dangerous. As an adult, they then experience every “forbidden” thought as proof that something is wrong with them. So in therapy we work not only with the thought, but also with the story of what one was allowed to feel.

It also often helps to talk about your thoughts with someone who isn’t frightened by them. Shame lives in hiding. Once you say a thought out loud and see that the other person hasn’t pulled away, it loses much of its weight. This is one of the reasons why people often say, after a first conversation about intrusive thoughts, that they feel lighter, even though the thought itself hasn’t changed yet.

Exercise: let the thought sit on a chair

This exercise is no substitute for therapy if your thoughts already shape your day. But it is a good start for anyone who would like to take some power away from their thoughts. You can try it today, the next time the thought appears.

1. Name it. When it comes, say to yourself: “I notice I’m having an intrusive thought.” Not the content, only the type. This lets you take a step back from it.
2. Notice your body. Where do you feel the distress — in your chest, your stomach, your throat? For three breaths just observe, without changing anything. Distress is unpleasant, but it is not dangerous.
3. Don’t answer it. Don’t try to convince yourself you don’t really mean it, don’t check, don’t seek reassurance. Imagine the thought is a guest who has sat down on a chair in the corner of the room. You don’t have to send them away, and you don’t have to entertain them.
4. Return to what you were doing. Carry on with whatever you were doing — washing up, driving, talking. The thought can stay on the chair while you get on with things.
5. Write down what happened. In the evening, write two lines about how long the thought stayed and what happened to the distress. After a few days you will probably notice that the thought fades faster than you expected.

If the exercise makes things worse, or if you find you can’t manage without the ritual, that is valuable information, not a failure. It tells you that you need a companion, not more willpower.

Where this explanation is not enough

Everything I have written applies to thoughts you don’t want — the ones that frighten you precisely because they go against who you are. But there are thoughts that are different, and with them, reassurance would be the wrong response.

If you experience thoughts of harming yourself not as foreign but as relief, as a way out or as a plan, these are not intrusive thoughts in the sense of this post. Then don’t wait: in Slovenia, call the crisis line Klic v duševni stiski on 01 520 99 00 (every day from 7 pm to 7 am), the Samaritans helpline on 116 123 (24 hours a day) or, in an emergency, 112. The same applies if you feel you might actually act on a thought and that possibility doesn’t frighten you.

Intrusive memories after trauma are also different — scenes that keep returning after a terrible experience. They too break in uninvited, but they come from something that really happened and need a different approach, usually with a therapist experienced in trauma.

And finally: exercises and understanding are not enough when OCD is already pronounced. Then it is right to see your GP, who can refer you to a psychiatrist or a clinical psychologist. Alongside psychotherapy, treatment may also include medication; that is a decision you make together with your doctor. For a broader picture of what research says about therapy and medication for anxiety, I wrote Therapy or medication for anxiety: what the research shows.

What to remember

• Almost everyone has intrusive thoughts — 94 per cent of people in an international study. Their content says nothing about your character.
• A thought gets stuck where you care the most, not where you secretly want something.
• Pushing thoughts away, checking and seeking reassurance make them stronger, because they tell the brain the thought is important.
• We speak of obsessive-compulsive disorder when thoughts and rituals take up a lot of time and shape daily life — and then help is effective and worth seeking.
• If you experience a thought of self-harm as a way out rather than as an intruder, don’t wait: in Slovenia, 01 520 99 00, 116 123 or 112.