I wrote last week about how when we get triggered by OCD obsessions (unwanted, intrusive, and distressing thoughts, images, urges, or feelings), it’s a faulty signal from our amygdala (part of the brain responsible for detecting potential threats), if we then give into the compulsion (a repetitive behaviour or mental act) it confirms the threat and fully triggers the fight or flight response in our body. 

Why is this an issue? 

Well, when in fight or flight we don’t tend to think rationally, we’re in survival mode and though this system can be useful at times, when it comes to OCD it’s not the place we want to be. 

It allows the irrational use of compulsions to ‘neutralise’ thoughts seem rational.  We see ourselves doing things we know are senseless, like retracing our steps, washing our hands multiple times, repeating safety phrases in our heads or ruminating endlessly on thoughts, but for whatever reason the brain has convinced us it will help. 

This is wrong, in fact compulsions do nothing but cause us more distress, more uncertainty and less trust in our own ability to cope!

So why does our body do this? 

According to ChapGPT it serves the following purposes:

The brain prioritizes speed over nuance.
In a threat situation, the amygdala, pushes the body to act quickly. Nuanced thinking takes time; survival favours rapid, simple judgments like safe vs. unsafe, friend vs. foe, stay vs. run.

It reduces cognitive load during stress.
Under high stress, the prefrontal cortex (responsible for reasoning and complex thinking) becomes less active. The brain simplifies decisions to conserve resources.

It minimizes hesitation.
Ambivalence can be dangerous during real threats. If you’re being chased, you don’t want to think:
“Well, maybe it’s dangerous, but maybe it’s not, and perhaps I should consider my options…”
You want an immediate, decisive action.

It helps coordinate the body’s physiological response.
Fight-or-flight relies on a clear appraisal: threat = act. Black-and-white thinking helps the brain send a strong, unified signal.

Why is this an issue in OCD?

When we believe our obsessions, which are being prompted by a fault in this system and give into our compulsions, we are triggering our fight or flight response repeatedly, the cascade of issues this causes is as follows:

The brain learns:

• Ambiguity = risk
• Nuance = unsafe
• Only extremes are predictable

So the nervous system keeps simplifying the world into binaries—even when there is no threat!

Our amygdala becomes hyper-reactive

A sensitized amygdala reacts to mild cues, (OCD obsessions) as if they’re major threats. This leads to rapid, black-and-white judgments like:

• “That bump in the road might have been a person”
• “I had a negative thought when I turned on the light, maybe I should turn it off again and make sure I think positive thoughts when I turn it on this time, just in case.”
• “There’s a tiny mark on that apple, I should probably throw it away and get another one, it’s probably poisonous.”

The prefrontal cortex, responsible for reasoning and nuance, gets less access as chronic stress reduces blood flow and connectivity in regions that support:

• Perspective-taking
• Emotional regulation
• Tolerance for uncertainty
• Gray-area thinking
• Long-term planning

In this state, the brain defaults to simple categories because complexity feels overwhelming.

When we have OCD, Fight-or-flight can turn into a trait instead of a temporary state!

When the sympathetic nervous system (fight or flight) stays activated long-term, the cognitive style that evolved for emergencies becomes our everyday thinking. 

This is why giving into OCD compulsions, even one, is only ever going to lead to more distress, more compulsions to try and relive that stress, sending you freefalling down that rabbit hole. 

We need to realise that the compulsion is not keeping us safe and remove it’s usefulness. 

I know from years of experience with OCD that there’s always another ‘what if?’ or ‘maybe?’ and whenever I’ve given into a compulsion all I’ve done is made things worse. I become withdrawn, irritable and irrational, simple tasks get overwhelming and life becomes very challenging. 

I understand it can feel impossible at times not to just do the compulsion, ‘just once more won’t hurt, I’ll sit with it the next time’ – sound familiar?  But I know from experience that it’s never going to feel easy, it’s always going to be challenging.

However knowing that the compulsion is useless, serves no purpose and will only make things worse, helps give me the strength to not give in.

I really hope this information helps you too. Let me know what you think in the comments below.
As always,
Stay Strong xxx