Intrusive thoughts: Why do we get them?

Intrusive thoughts

Did you know that the average person has around 12-60 thousand thoughts per day? A study by the National Science Foundation found that 80% of those can be negative thoughts. Let that sink in for a moment.

If we are having that many thoughts per day, and a big chunk of them are not positive, is it any surprise that some of us struggle with intrusive thoughts that can affect our day to day lives? Probably not. Unfortunately, the brain is wired towards negative thinking, this goes back to the human response of fight or flight and the need for survival. As environments and people change, the brain often gets left behind. Understanding how and why our brain processes thoughts is fundamental in any mental health condition, and intrusive thoughts are no different.

Intrusive thoughts can take any form, but they are usually formed around concerns for yourself or someone you care about. The truth is every single person on the planet experiences intrusive thoughts. The content of these thoughts may be alien, scary or confusing but can pass after a few moments. Sometimes though, these thoughts can alarm us so much that they stick around for longer, which can result in conditions such as Obsessive-Compulsive Disorder, but that is not to say if you have intrusive thoughts that you have OCD.

These thoughts that can stick with us are unwanted, often disturbing thoughts that cause us deep anxiety and distress. It’s our anxious response to them that fuels the intrusive thought cycle and therefore, we are not capable of brushing them aside and labelling them as meaningless.

We feel like we have to find out more about the origin of the thought and what it means about us as a person.

So why do we get intrusive thoughts?

As mentioned above, our brain is wired more towards negative thinking, and with that, some intrusive thoughts are inevitable. But why do they stick with some people when others can let them flow in and out? There is no clear answer to this, but a good analysis would be that it’s down to the response to the initial thought, which can form the path in how the thoughts grow or dissolve. How some can let them come and go and how others latch onto them.

For example, an individual with a naturally overactive brain, or anxious tendencies could react to an intrusive thought from a feeling of fear, meaning there is something to be scared of. This reaction often occurs if the theme of the thought targets something very important in that person’s life. This reaction then makes the individual think that because they have had the thought, that they may act on it. This, in turn, makes the thought more threatening and can spiral into a confusing and scary place, showing the brain that there is something to be concerned about. But so often there is not, it’s merely our immediate reaction to the thought (increased heart rate, questioning the validity, digging for answers) and not a reflection of our life or values, that fuels the anxious cycle.

Examples of unwanted intrusive thoughts that can cause distress:

  • Pushing someone in front of a train, or jumping in front of a train yourself
  • Hurting a child
  • Questioning your relationship
  • Shouting out unpleasant comments in public
  • Questioning your sexuality
  • Thoughts about suicide
  • Crashing into a wall when driving


The examples above are all disturbing to people in one way or another, and what they all have in common is that these thoughts go against what the person knows themselves to be. Either in terms of their behaviour or their beliefs and values about themselves and their lives.

People bothered by intrusive thoughts need to form a new relationship with them—that their content is irrelevant and unimportant.

That’s where CBT comes in. Cognitive behavioural therapy looks at the connection between how you think, how you feel and how you behave. How you approach these unhelpful thoughts and self-talk can help you work out different ways of thinking and behaving so you can cope better; whatever life may bring.

Some tips for overcoming unwanted intrusive thoughts:

  • Label these thoughts as “intrusive.”
  • Accept and allow the thoughts into your mind.
  • Educate yourself on the brain and how it works.
  • Do not try to push the thoughts away – but gently move your attention on to something else.
  • Practice allowing time to pass.
  • Do not engage and search for the meaning of them.
  • Expect the thoughts to come back again.
  • Continue whatever you were doing prior to the intrusive thought while allowing the anxiety to be present.


Cognitive behavioural therapy is a way for you to discuss distressing thoughts with a mental health expert.

If you would like to talk to a professional about your intrusive thoughts, we are here to help.

Which condition do you require support with?

Learn which conditions are treatable with CBT therapy.
Book an Appointment
We offer online, phone or face to face therapy. Contact us to get matched to the right therapist for you.
Book appointment