PTSD vs Complex PTSD: What’s The Difference?

Complex PTSD vs PTSD(1)
Complex PTSD vs PTSD(1)

As a qualified mental health professional, you’ll already be familiar with the terms Post Traumatic Stress Disorder (PTSD) and Complex Post Traumatic Stress Disorder (C-PTSD). Some of the children and young people you work with will have experienced an event that made them feel under serious threat from harm and these kinds of events can stay with the child or young person, impacting how they feel and how they cope with everyday life. 

The understanding of PTSD in children and young people has developed over the past decade, which has in turn resulted in better treatment and a better prognosis for those who seek help. 

As a mental health professional working with children and young people, ensuring you have a good understanding of PTSD and C-PTSD – and the differences between them  – can help you to recognise it in the young people you work with, so you can help them to access the right kind of support quicker. 

The PTSD Diagnostic Criteria

PTSD is a mental health disorder that occurs when a child, adult or young person experiences a traumatic event in which they believed that they were at risk of serious harm or death. 

Unlike general trauma, which can occur from distressing and upsetting events, PTSD can occurs from events in which the person perceived that they were in severe or life threatening danger and reacted with horror and shock at the time. In the case of a child, PTSD can also occur when their caregiver is the one at risk. 

Some examples of this include; 

  • Assault or rape
  • Accidents 
  • Natural disasters 
  • Terrorist attacks 
  • War, genocide or other violent events 

In order to make a PTSD diagnosis, the person in question must meet certain criteria, and they must be experiencing all of the key symptoms for more than 1 month. 

According to the DSM-5 the four-point diagnostic criteria for PTSD includes; 

1: Intrusive thoughts – including memories, flashbacks, feelings and nightmares. 

2: Avoidance – including avoidance of certain people, places, circumstances and memories. 

3: Physiological changes – including hypervigilance, emotional dysregulation, poor concentration and angry outbursts. 

4: Mood and behaviour changes – including low mood, loss of interest in activities, poor self-worth and increase in negative emotions. 

The ICD-11, more commonly used in Europe, has a slightly different 3-point diagnostic criteria, omitting the mood and behaviour changes. 

How Does PTSD Present In Children?

PTSD requires a different treatment approach to trauma or other mental health problems, so it’s important to be able to recognise it in the children and young people you work with, so you can ensure they get the treatment they need to make a full recovery. 

Knowing the diagnostic criteria for PTSD is helpful, but understanding how these symptoms present in children and young people can help you to recognise it swiftly. 

Intrusive Memories 

A child or young person with PTSD may find that memories of the event just “pop” into their head with no trigger and no warning. These memories will be persistent and they may find it hard to stop thinking about them. 


Nightmares are a common occurrence in children and young people with PTSD. The nightmares may involve reliving the event, or the content of the nightmares may be different but the feelings are the same feelings associated with the traumatic experience. 


Children and young people may experience flashbacks in which they feel like they are reliving the event again. Flashbacks can present in children as periods of dissociation, angry outbursts or panic and anxiety attacks. 


Avoiding places, people or circumstances that may trigger memories of the traumatic event is common in PTSD. A child or young person may start refusing to attend places in which they were always comfortable before the event or might withdraw from certain people whom they associate with the event. It’s possible for the avoidance to become more generalised too. For example; a child who was involved in a car crash might avoid travelling in cars, or they might start avoiding anywhere with any form of transport. 

Tantrums & Angry Outbursts 

A child experiencing PTSD may start to have angry outbursts, temper tantrums or may start lashing out at the people around them. You might find that a child who was previously calm becomes more aggressive, or a young person who was usually good-natured is now unable to keep their temper under control. 

Loss of Interest  

Loss of interest in activities can be symptoms of PTSD too. You might find a child experiencing PTSD doesn’t want to go out or see their friends or they no longer wish to participate in sports they once loved. 

Low Mood & Increased Negative Feelings 

Low mood, lack of motivation and an increase in negative emotions are all associated with PTSD. A child may start to self-criticise, become anxious, feel sad, guilty or ashamed. This can present in many different ways, including withdrawing from social interactions and activities, negative self-talk or outbursts. 


Hypervigilance is one of the most common symptoms of PTSD. A child with hypervigilance may be unable to “switch off” or relax. They might seem anxious and distracted and appear to be unable to focus on conversations or school work. They might engage in protective behaviours such as sitting with their back to the wall so they can see the door. 

Heightened Startle Response 

The startle response in children with PTSD is often much more sensitive. This results in a child appearing to be more “jumpy” around noises or anything that causes a startle response. 

Complex PTSD vs PTSD(2)

Complex PTSD Diagnostic Criteria

Complex PTSD usually develops when people have experienced traumatic events at key developmental stages in their early life.

For a complex PTSD diagnosis, a person must meet the the 3-point ICD-11 criteria for PTSD and they must also be experiencing persistent difficulties in the following; 

Emotional Dysregulation Difficulties

  • Emotional responses not typical for a given situation
  • Persistent low mood, sadness or depression
  • Irregular anger responses, either inhibited or explosive 

Negative Self Concept 

  • Deep feelings of worthlessness
  • Persistent feelings of guilt or shame 
  • Feeling flawed or damaged 
  • Feeling hopeless, powerless or defeated. 


Difficulties In  Relationships 

  • Difficulty with connecting closely with others
  • Avoiding relationships or being too “full on” in relationships
  • Trust issues 
  • Feeling betrayed or hurt easily 

Treating Children With PTSD or C-PTSD

Working with children and young people, knowing how to recognise the signs of PTSD and C-PTSD can help you to spot when a child might need specialised treatment. Often treating PTSD or C-PTSD first can result in a resolution of other symptoms, which is why it’s recommended that in cases of PTSD that it’s treated first. 

Specialist therapies designed for PTSD specifically, such as CATT, can help bring marked results and lead to a full recovery, especially when treatment begins promptly. 

CATT is a specialist child trauma therapy designed specifically for children with PTSD and complex PTSD. If you’d like to learn more about CATT and how you can use it to enhance your therapeutic practice here…

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I was delighted to attend the CATT online training course after having seen the wonderful impact of CATT on children during one of my clinical psychology training placements. I am extremely interested in the value of play in therapeutic approaches, so CATT fits the bill perfectly. It is a child-centred, non-stigmatising and effective approach. The training I attended was thoughtful, professional and experiential and the trainers were approachable and knowledgeable. I would highly recommend this course.
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Sharon Twigg
The CATT training we excellent! Great resource booklet, fabulous tuition on the theory and practice as well as group work. The pace and level of teaching was perfect. I felt really enabled to try the method out safely online with other colleagues on the course. I have used the method successfully now with young people and teenagers in CAMHS who could not tolerate EMDR or TF-CBT due to the intensity of their symptoms. It has also worked well with kids with Autism, using toy figures or Lego. This method is now one of my top 3 go-to tools for trauma. Thank you :)

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PTSD vs Complex PTSD: What’s The Difference?

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