The Difference Between Single Episode Trauma and Complex Trauma

There is a difference between single episode trauma and complex trauma and whether you are a therapist, a client, or someone who is interested in learning about trauma it’s helpful to understand the difference, here is why: 

In order to effectively treat trauma we have to understand what type of trauma we are working with; this in turn helps us understand how the event(s) impact the stress response systems and what type of events may cause either 

Post Traumatic Stress Disorder or 

Complex Post Traumatic Stress Disorder. 

Trauma has been hard for the world to define, this is because whether or not an event was traumatic depends on how the individual experiences the event. What may be traumatic for one person may not be traumatic for another. This depends on many factors including the timing of the event, the way the event is perceived by an individual, and whether or not the individual’s stress response system was activated in an extreme or prolonged way.   To help with defining trauma SAMHSA (The Substance Abuse and Mental Health Services Administration) convened a group of academics and clinicians and conceptualized the 3 E’s definition of trauma.  The 3 Es are 3 main components:

  1. Event (For example an accident, natural disaster, a break up)

  2. Experience (For example it was experienced as overwhelming, induced panic, possible dissociation)

  3. Effects (these are the symptoms that exist after the event such as nightmares, panic attacks, changes in mood, avoidance etc.)

To determine whether an event was traumatic you would need to identify a specific event, understand how the person experienced the event, and explore what the effects were-if you’ve got something in all 3 categories then you’ve got trauma.

So let’s say that a person has a single episode event such as a car accident and up until this point in their life things have been stable. For this person there haven’t been any other traumatic events, they’ve had minimal significant life transitions, they have healthy relationships, and we assume they have a pretty healthy stress response system. Then after the accident they develop:

  • Flashbacks

  • Nightmares

  • Avoidance symptoms

  • Panic Attacks

  • AND their symptoms persist past 1 month

We would say that this person has Post Traumatic Stress Disorder and we would likely treat the person’s symptoms with combination of:

  • Supportive Counseling

  • Psycho-education

  • CBT

  • EMDR

  • Med Referral

We would expect that although the person would never be exactly the same again that with time and treatment they would be able to recover and that they would return to a regulated state that was baseline for them before the accident and that this baseline of a regulated state is a familiar place for them to return to.

Now let’s say that a person has experienced Complex Trauma.  For example, a baby who experienced high levels of stress while in utero, exposure to toxins while in utero or it’s mother was in an unsafe environment, perhaps there was domestic violence.  Then the baby is born and the parents are distracted by food insecurity and are living in poverty.  All of these events and experiences are happening when the brain is having it’s most rapid development and so this baby’s stress response systems are developing in response to stressors in the environment.  The baby is experiencing trauma during developmental periods that will impact that way that the brain continues to develop. 

Unfortunately, this was very misunderstood for a long time and people believed that it didn’t matter what happened to children because they wouldn’t be able to “remember”; that children were “resilient.” Now we know this couldn’t be further from the truth.  As Dr. Bruce Perry says, “children are not resilient, children are malleable.” Complex Trauma is trauma that is:

  • Unpredictable

  • Prolonged/ongoing (such as in the case of abuse or neglect)

  • Within the context of important relationships

  • Occuring during key developmental period of life 

When a person experiences complex trauma they are at high risk for developing a sensitized stress response system, which is one that is very sensitive to stress.  

When there is a sensitized stress response system it is possible to develop Complex Post Traumatic Stress Disorder (CPTSD). This can be very confusing because CPTSD can look like a myriad of many familiar diagnoses, if it is often said that trauma can mirror any mental health diagnosis.  A complex trauma survivor might say something like, “I don’t have memories, I have symptoms.” Because of this,  the treatment for Complex Trauma is different from treatment for Single Episode Trauma and often involves working around themes of attachment, self-regulation, self-esteem, relationship building, attunement, empathy, and acceptance.

No matter the kind of trauma you have experienced 

post traumatic healing and growth is possible. 


In health and healing,

Dana