Intrusive Thoughts and Anxiety: Why They Happen and What to Do

Most people have had the experience of a thought arriving that they didn't want, didn't invite, and couldn't immediately explain. A sudden image of something terrible happening. An impulse that contradicts everything they value. A fear that lodges itself in the mind and refuses to move despite every effort to dislodge it.

For many people, these thoughts arrive and pass without leaving much of a mark. For others — particularly those living with anxiety — intrusive thoughts become a significant source of distress in their own right, producing shame, confusion, and a level of suffering that often goes unaddressed because the thoughts feel too disturbing to say out loud.

This post is an attempt to explain what intrusive thoughts actually are, why they're so closely connected to anxiety, and what actually helps — including why the most instinctive responses to them tend to make things worse.

What Intrusive Thoughts Actually Are

Intrusive thoughts are unwanted mental content that arrives spontaneously — thoughts, images, impulses, or doubts that the person experiencing them didn't choose and often finds distressing precisely because the content conflicts with who they are and what they value.

Research on intrusive thoughts has consistently found that they are not a clinical phenomenon. They're a universal human experience. Studies across cultures and populations show that the vast majority of people — including people with no anxiety disorder or mental health concern whatsoever — experience intrusive thoughts with content that is violent, sexual, blasphemous, or otherwise disturbing. The thoughts themselves are not the problem.

What distinguishes the ordinary intrusive thought from the clinically significant one isn't the content. It's what happens next.

For most people, an unwanted thought arrives, is recognized as strange or unpleasant, and is allowed to pass. The person doesn't take it seriously as a signal of intent or character. They don't attempt to suppress it. They don't engage in extensive mental argument with it. It moves through the mind the way thoughts move through minds — briefly, without leaving much behind.

For people with anxiety, the thought arrives and gets stuck. Not because of the thought itself, but because of the response to it. The anxiety system treats the thought as a threat — something that needs to be managed, suppressed, analyzed, or neutralized. And the effort to do any of those things is precisely what keeps the thought present and amplifies its apparent significance.

Why Anxiety and Intrusive Thoughts Travel Together

The relationship between anxiety and intrusive thoughts is one of the most important things to understand if you're dealing with both.

Anxiety operates by keeping the threat-detection system in a heightened state of alert. The nervous system is scanning constantly — for danger in the environment, for social threats, for evidence that something might go wrong. That scanning extends to the mind's own content. When an anxious nervous system encounters a thought with disturbing content, it flags it as significant. Something to pay attention to. Something to understand. Something to make sure isn't dangerous.

That flagging is the problem. In treating the intrusive thought as a significant signal — something to be suppressed, analyzed, or guarded against — the anxious mind does the one thing most likely to keep it present. Research on thought suppression is unambiguous on this point: attempting to suppress an unwanted thought reliably increases both its frequency and its perceived importance. The classic demonstration is the instruction not to think of a white bear, which reliably produces an immediate and persistent white bear. The same mechanism applies to intrusive thoughts: the effort to get rid of them keeps them coming back.

The anxiety also distorts the meaning attributed to the thoughts. For people with anxiety, intrusive thoughts don't feel like mental noise. They feel like signals — about character, about danger, about who the person really is underneath. A thought about harm coming to a loved one feels like evidence of dangerous intent. A violent image feels like a glimpse of a dark self. A doubt about a relationship or a decision feels like a truth trying to surface. These interpretations are anxiety's work, not accurate readings of the thoughts' significance.

The Thoughts People Are Most Afraid to Say

The content of intrusive thoughts that produces the most distress tends to fall into a few recognizable categories — and these are often the thoughts people are most afraid to disclose, because the content feels most incompatible with who they believe themselves to be.

Harm-related intrusive thoughts — images or impulses involving causing harm to a loved one, a child, or themselves — are among the most common and most distressing. New parents frequently experience intrusive images of harm coming to their baby, which produces intense shame in people who love their child profoundly. People who care for vulnerable family members sometimes have intrusive thoughts about harming them. These thoughts are not desires. They are the anxiety system generating worst-case scenarios around the most significant attachments the person has.

Relationship and orientation doubts — a persistent, unwanted questioning of whether you love your partner, whether you're attracted to someone you shouldn't be, whether your sexual orientation is different from how you've understood it — can become consuming and destabilizing in ways that have more to do with the anxiety attaching to doubt than with any genuine unresolved question.

Blasphemous or morally offensive thoughts — thoughts that contradict a person's deepest values, religious beliefs, or sense of decency — are particularly distressing for people to whom those values are genuinely important. The content of the thought feels like a betrayal of who they are.

And contamination-related thoughts — fears about illness, germs, harm from touching certain things or being in certain places — that produce avoidance and compulsive behaviour characteristic of OCD presentations, which sit in close relationship with anxiety.

Creating Space for What's Difficult to Say

Daniel Burgoyne, Registered Psychotherapist at Reset Counselling & Psychotherapy, understands that the most significant therapeutic work often happens in exactly the territory that feels most difficult to approach: "Sometimes we're getting into pretty uncomfortable topics, but I like to create a safe, open environment where those things can be addressed. Sometimes it's something the client has never really allowed themselves to feel. So opening up that space to be themself — and then we can dig into underlying core beliefs, values, experiences and understanding of what they can control and what they can't control."

That description captures something essential about why intrusive thoughts respond so well to therapy — and specifically to a therapeutic relationship in which nothing is too disturbing to bring into the room.

Many people carry intrusive thoughts for years without ever saying them out loud to anyone, because the content feels too shameful, too frightening, or too likely to produce alarm. They manage them privately — through distraction, suppression, ritual, or the exhausting effort of keeping their inner life hidden from everyone around them. The relief of finally saying a thought out loud to someone who receives it without alarm — who recognizes it as an anxiety symptom rather than a character revelation — is often one of the most significant experiences early in therapy.

That reception changes the thought's relationship to the person carrying it. The thought that has been kept in the dark, surrounded by shame and secrecy, tends to lose some of its power when brought into a safe, non-judgmental space. Not because it disappears, but because the fear around it begins to change.

What Actually Helps

Understanding what actually helps with intrusive thoughts requires understanding what makes them worse — because most people's instinctive responses are the ones that maintain and amplify the thoughts rather than reducing them.

Suppression makes them worse. The research is clear: trying not to think a thought increases its frequency and its perceived significance. The effort to push the thought away is precisely what keeps it present.

Reassurance-seeking makes them worse. Checking with a partner, a friend, or the internet to confirm that the thought doesn't mean something terrible about you brings temporary relief and long-term maintenance — because the relief teaches the anxiety that reassurance-seeking is the appropriate response to the thought, which keeps the anxiety generating the thought in order to produce the seeking.

Engagement and analysis make them worse. Attempting to understand the thought, to determine what it means, to assess whether it reflects something real about your character or intentions — this is treating the thought as a significant signal that warrants investigation. The investigation confirms the thought's apparent significance and keeps it present.

What actually helps operates on a fundamentally different principle: rather than responding to the thought as a threat that requires management, learning to relate to it as mental noise that doesn't require a response.

Defusion — a concept from Acceptance and Commitment Therapy — involves creating distance between the thought and the thinker. Rather than "I want to harm my child," the shift is to "I'm having the thought that I want to harm my child." That linguistic distance is small and experientially significant. It locates the thought as a thought — something the mind produces — rather than as a truth or an intention.

Mindful observation — watching thoughts arrive and pass without engaging with them, without trying to change them, without attributing significance to their content — builds the capacity over time to relate to intrusive thoughts the way a person with no anxiety disorder does: as mental noise that doesn't warrant a response.

Exposure and response prevention, the core approach in OCD treatment which also applies to intrusive thought presentations more broadly, involves deliberately allowing the thought to be present without engaging in the management behaviours — the suppression, the reassurance-seeking, the avoidance — that have been maintaining the anxiety. Over time, the thought loses its charge. The nervous system learns that the thought doesn't require a response and that tolerating it is survivable.

When Intrusive Thoughts Are Part of OCD

Intrusive thoughts are the hallmark feature of OCD, and it's worth noting the distinction between intrusive thoughts driven primarily by anxiety and the more specific OCD presentation where intrusive thoughts are accompanied by compulsions — the ritualistic behaviours or mental acts performed to neutralize the anxiety the thought produces.

Many people with OCD don't recognize their experience as OCD because their compulsions are mental rather than behavioural — internal reassurance-seeking, reviewing and analyzing, mentally replaying events to check for evidence of wrongdoing. The absence of visible rituals doesn't mean OCD isn't present.

OCD presentations respond specifically to ERP — Exposure and Response Prevention — which is distinct from general anxiety treatment and requires specific clinical training to deliver effectively. When intrusive thoughts are accompanied by the compulsive pattern, finding a therapist with specific OCD training is important.

Anxiety and Intrusive Thought Therapy in Barrie

At Reset Counselling & Psychotherapy, Daniel Burgoyne and members of our team offer anxiety counselling for people navigating intrusive thoughts, the shame they produce, and the anxiety patterns that maintain them. We use CBT, ACT, EFT, and mindfulness-based approaches, in a space where nothing is too difficult to bring into the conversation.

In person at our Barrie location and virtually across Ontario. No referral needed.

Book a session with our Barrie anxiety counselling team →



Reset Counselling & Psychotherapy is located at Unit 201-151 Essa Road, Barrie, ON. We offer anxiety counselling, individual therapy, and a full range of mental health services, in person and virtually across Ontario.