The Neurobiology of Posttraumatic Stress Syndrome – You’re Not Crazy! There’s a reason why you’re feeling the way you are after infidelity.

The Neurobiology of Posttraumatic Stress Syndrome
The Neurobiology of Posttraumatic Stress Syndrome

by Joyce E. Smith, MA, MFT

Licensed Marriage & Family Therapist

Trauma Specialist * EMDR Certified

You’re Not Crazy!  There’s a Physiological Reason Why You’re Feeling the Way You Are.

In my last article “What Does the Betrayal of Infidelity Have to do with Posttraumatic Stress Syndrome?”, I talked about the psychological correlation between your feelings of betrayal and posttraumatic stress syndrome, or PTSD.  In this article, I’m going to deal with the physiological side. Hopefully after reading this, you’ll understand why you’re not crazy!!!

For some of you, it may be several months (or even years!) since discovery day of your partner’s affair.  No matter how hard you try, you just can’t seem to shake the residual anxiety and stress. You keep getting triggered over and over again – sometimes by what appears to be the smallest thing.  At this point you may be beginning to think you’re doomed to be an emotional wreck for the rest of your life.  There IS hope, and you CAN heal from this, which I’ll be discussing in the third article of this series: “Methods to Help You Cope and Heal from Posttraumatic Stress Syndrome Caused by the Betrayal of Infidelity.”

First, let’s first break up and define the words of PTSD.

From the first word, posttraumatic, we get “post”, meaning after, and the word “traumatic”. An easy way to define trauma is something that is either too much too fast, or too little for too long.  In the case of betrayal of infidelity, I’d say it’s a bit of both.  While the infidelity was occurring, something was probably lacking in your relationship, i.e. too little for too long. This was probably (at least in part) due to energy being funneled into the affair, which your partner should have been channeling into their relationship with you.

Usually with the betrayal of infidelity, the much greater part of the trauma is associated with the initial discovery – which is WAY too much, WAY too fast, right?  Even in slow motion, it would still be too fast.  In fact, I’ll bet if you could rewind to that exact moment and delete it, you’d be first in line!

Next, we come to the word “stress.”  

If you’re reading this article, I’m guessing you’ve got a pretty good idea what stress feels like, so let’s move on to “syndrome.”  According to the Merriam-Webster Dictionary, syndrome is “a group of symptoms that consistently occur together, or a condition characterized by a set of associated symptoms.”  So, putting all this together, basically what PTSD is referring to, is a residual feeling of stress (and anxiety) that continues to be triggered long after the discovery of the betrayal.

See also  Post Traumatic Growth After Infidelity: The 3 Ingredients That Make It Possible

So now you’re probably saying “Well, duh – I know the affair is over and I’m still getting triggered, but why??? Let me side step a bit and give you a very brief description of something called our Autonomic Nervous System, or ANS.  As the first part of the word “auto” implies, this is something that happens automatically. Think of it as something akin to breathing – most of the time we don’t give it a second thought.  It’s purely instinctual, and there’s nothing conscious about it.

Contained in our ANS are two branches: the Sympathetic Nervous System or SNS, and the Parasympathetic Nervous System or PNS.  The SNS (think stress) gets our organs ready for action, causing an increase in our breathing rate, blood pressure, heart rate, stress hormones, sweating, and our pupils to dilate.  Our PNS causes a slowing down in the same areas. Under normal circumstances, there’s a gentle ebb and flow between the two, which looks something like this:

sympathetic nervous system

The Impact of Trauma on Our Nervous System: Fight, Flight, and Freeze

When we experience trauma, our SNS kicks into action when we perceive that in order to survive, we must either physically defend ourselves, or get out of there fast!!!  This is referred to as “fight or flight.” There is also a third component which most people are not familiar with called “freeze.” This results when we perceive we’re not able to “fight or flight”.  When this occurs, we’re usually left feeling a tremendous amount of guilt and shame. All those times you find yourself asking “Why didn’t I?”, “I can’t believe I didn’t!”, etc.  It’s because you physiologically couldn’t!  

When there’s a traumatic event (like discovery of your partner’s infidelity), or any trigger of that event, our ANS goes nuts, ping-ponging out of control. In addition, sometimes you might become “stuck on high”, filled with rage, anxiety or always feeling on edge. Other times you might become “stuck on low”, better known as depression.  This can happen when you burn out from being “stuck on high” for too long.  Below is an illustration of what all of this might look like.

See also  There is No Quick Fix to Healing and Recovering from an Affair

bumped out resilient zone

Are you starting to feel a little less crazy? 

Let me explain some more about the circus of our neurobiological hijacking.

Tucked inside our brain is a little area called the amygdala which registers fear. It’s also in cahoots with our inherent survival mechanism. In order to survive in the world, it’s important to stay away from anything that threatens our existence.  So……., when there’s a perception of something endangering our sense of safety, our inherent survival mechanism kicks into action with a laser like quality.  Its sole task is to make sure we recognize and avoid anything remotely related to the original trauma so we never have that experience again.

In order to educate our own personal mental swat team, in the moment of trauma, our brain takes a snapshot-like photo of everything thing related to it – and I mean everything! It could be a color, a smell, the time of day, a specific word, a blond woman, or any woman for that matter. Oh yeah, and what about your partner.  Do you think they just might be a trigger too??? You get the idea.  Much like shards of broken glass, each individual trigger is filed away in a separate compartment of our brain, in the “to deal with later” section, all tied together by the word “danger.”   

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Regaining Control:
Dealing With Obsessive Thoughts, Triggers and Memories of the Affair

Arm yourself with a variety of techniques, practical strategies and  knowledge to help you to manage those intrusive thoughts, triggers and memories of your partner’s affair.

If this is getting a bit too technical, hang with me just a little bit longer.  I’m about to tie this all together. 

The left side of our brain contains our rational and logical functions.  This part has a timeline.  It’s also able to correctly put things that have occurred in the past, in the past. Now the right side is a different story. This side ties into your emotions and your inherent survival mechanism. When you’re triggered, this side takes over before you can blink.  Your rational thinking instantaneously goes into shut down mode and is temporarily inaccessible.  Think about it. If there’s a tiger staring you in the face, is your first thought going to be “Hmmmm, what should I make for dinner?” or “GET ME OUT OF HERE!!!” (Gee, do you think this just might have something to do with why your memory appears to have gone on strike?)

See also  Methods to Help You Cope and Heal from Posttraumatic Stress Syndrome Caused by the Betrayal of Infidelity

When we’re triggered by something, it’s generally either related to something in the past, or something we’re afraid is going to happen in the future.  Unfortunately the emotional or right side of our brain doesn’t have a sense of time, and reacts as if there’s only NOW!!!!! When we sense any one of those triggers, our brain and nervous system screams DANGER!!! Suddenly, faster than the speed of light, we’re teleported back to the exact moment the trauma occurred, as if frozen in time – like we’re stuck in some vicious time warp. You may not be able to currently see any evidence of the trauma, but you’ll have a tough time trying to convince your nervous system.

Understanding the Lingering Effects of Infidelity and Past Traumas

I hope you’re beginning to understand why the betrayal of infidelity lingers like a nagging mosquito. If you’ve had prior traumatic experiences (e.g., rape, physical or sexual abuse, a car accident, growing up in an alcoholic household), each event has its own triggers. When these triggers overlap with betrayal, all those neural networks light up together, like one giant nuclear explosion. Yikes!!!

At this point you may have forgotten in the beginning of this article I said “there IS hope and you CAN heal!”  Stay tuned for the last article of this series at the beginning of next month, “Methods to Help You Cope and Heal from Posttraumatic Stress Syndrome Caused by the Betrayal of Infidelity.”

*This is the second in a series of three articles pertaining to Betrayal and PTSD.  To read the first article in the series, click here.  For the third and final article in the series, you can go here.

**Additionally, we spoke with Joyce by phone and recorded it.  You can access this interview from here.


Joyce E. Smith, MA, MFT, is a licensed marriage and family therapist, trauma specialist and certified EMDR practitioner. In addition she is trained in somatic therapy, expressive art therapy, sandtray therapy and child centered play therapy. She has a private therapy practice in Hollywood, CA. You can find more information about Joyce on her website:



    7 replies to "The Neurobiology of Posttraumatic Stress Syndrome"

    • Teresa

      Thank you Joyce for explaining all of that, and making it so easy to understand…even today, over 20 months since Dday, I had another trigger…now I understand why…
      I think every person who finds themself in this awful place should read these articles first, they explain so much the thoughts and feelings of those that are betrayed!

      Doug, maybe you should make these articles the headliner for this site! The first thing people see…or send them out in an email as a sort of “welcome” package! :/

      • Doug

        Good idea Teresa. I’ll think of a way to do just that once the final article has been posted – you may need to remind me! 😉

    • Natalia

      Thank you Joyce, I needed to read this today. I feel better knowing why I feel the way I do when I’m confronted with triggers. It’s been 2.5 years since Dday and even though my life is better it’s still not where I want it to be. Waiting to find out how to manage this mess I’ve got in my head.

    • CookieMomster

      Almost seven months post D-Day I really need to see that there is hope, even if it is 2-4 years off. I was starting to think this was forever! Triggers make me physically ill on an almost daily basis and I vacillate between anger and depression constantly, even though intellectually I know the EA is over.

    • Hopeful

      CookieMonster, I hear you. The 7th month mark was still really hard but things did seem to begin turning around for me then, in part (for us) because my H had finally told the WHOLE story or at least as close as it was coming and needed to come. Now it is maybe month 14th and I still think about it everyday but more in a passing way now. Triggers happen but tend to be easier to diffuse. IT was important for my partner to understand PTSD and how triggers worked, so that he helped comfort me and reassure me, rather than become defense or behave as though I am consciously trying to stick it to him, which I think was happening on some level. When I was triggered it was on this biological level and he was trying to ask me to rationalize what was happening in the middle of the storm, and it led to no good. But, I think we both have better tools and understanding and he has to set aside his guilt to help and I have to dig deep as well. Seeing someone who works with trauma has helped provide relief and tools.

      And, I am ‘hopeful’.

    • ralph

      I was betrayed by my wife of 18 years . We just had a baby one year old when I found out she was having a 6 month affair with a man she worked with, that was divorcing his wife.
      We stayed married but I had varying degrees of PTSD over the 40 + years we have been married. We have had mostly good times over the 40 years but she now has had dementia for about 10 yrs and I am her care taker.
      With the dementia there is loss of communication, affection and work like I have never done. I am just telling this because I thought people should know an extraordinary passage of time and things can still hurt almost as much as they did 40 years ago, even when you have them under control most of the time.

      • Sam

        My wife’s affair was 20 years ago and sometimes I am still triggered, like when a friend of ours recently flirted with her, telling how much he liked being physically close to her and another time how he thought she was sexy, and she said nothing back to him. Just to me that it made her very uncomfortable. Why not tell him? Why not tell him he was being inappropriate and crossing the line. She says there is no threat and I know this is true rationally, but my subconscious brain does not know this. He IS a threat to my subconscious brain, even though I know he is not. He is a very unattractive, and I think, a happily married man. We are friends with both he and his wife. I’ve gone into therapy and am doing EMDR because even though the affair was 20 years ago, there is still immense pain buried somewhere in my subconscious. She dragged me though hell for over a year, first an EA, then ending it on a monthly basis and finally moving out to be with her affair partner. It wasn’t until I got involved with someone else that she finally dumped her affair partner.

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