The short answer
PTSD usually follows one event or a short run of events: an accident, an assault, a disaster. Complex PTSD (CPTSD) usually follows trauma that went on for a long time and was hard or impossible to escape, most often within relationships, and often in childhood.
CPTSD includes everything that belongs to PTSD, plus three more areas of difficulty. The World Health Organization recognises both as separate diagnoses in ICD-11.
What PTSD and CPTSD share
Both have the same three core groups of symptoms.
- Reliving it
- The trauma comes back as if it were happening now: flashbacks, nightmares, or a sudden rush of fear or body sensations when something reminds you.
- Avoidance
- Steering clear of thoughts, feelings, places or people linked to what happened.
- A sense of threat
- Feeling on guard, jumpy and scanning for danger, even when part of you knows you're safe.
What CPTSD adds
With complex PTSD, three more areas are affected. ICD-11 calls them disturbances in self-organisation. In my experience they're usually what brings people to therapy, more than the flashbacks.
- Emotions
- Feelings that are too much or too little: overwhelm, rage and panic, or numbness and shutting down.
- Self-worth
- A deep and lasting sense of being worthless, defective, guilty or ashamed.
- Relationships
- Difficulty feeling close to people, or staying close. Wanting connection and fearing it at the same time.
Research supports the split. In a study of people seeking help after interpersonal trauma, those whose trauma had gone on for a long time were more likely to show the CPTSD pattern, and it went with more difficulty in daily life (Cloitre et al., 2013).
“PTSD asks what happened to you. CPTSD also asks who you had to become to get through it.”
CPTSD symptoms in adults
In adults, complex PTSD rarely looks like it does in films. It can look like being very capable at work and falling apart in close relationships. Like going numb when someone is kind to you. Like an inner critic that never switches off, or the feeling of watching your own life from the outside.
Many of the people I see have collected several diagnoses over the years, depression, anxiety, sometimes borderline personality disorder, before anyone asked about the long stretch of trauma underneath.
Why the difference matters
The difference isn't academic. It changes how I work. With PTSD after a single event, we can often go to the memory fairly soon, and EMDR or another trauma-focused therapy can bring relief in a limited number of sessions.
With CPTSD there's rarely one memory. There's a climate: years of fear, neglect or unpredictability. The emotional and relational difficulties need attention in their own right, alongside the memories. So we build enough stability and trust first, then work through what still feels present at a pace your system can hold. That doesn't mean waiting forever. Many people with CPTSD do very well with trauma-focused therapy when it's paced well, including in intensive formats.
Can PTSD turn into CPTSD?
Not exactly. They're different patterns rather than stages of one illness. But it's common for someone to come to therapy with PTSD after one recent event, and for a much longer history to appear once we look more closely. A car accident or an assault in adulthood can wake up far older experiences of being unsafe or alone. When that happens, the picture is often closer to CPTSD, and the treatment plan changes with it.
Is CPTSD in the DSM-5?
No. The American diagnostic manual doesn't list complex PTSD separately, so clinicians who use it may diagnose PTSD and describe the other difficulties alongside. ICD-11, used in many countries, recognises CPTSD as its own diagnosis.
You don't need a diagnosis to start therapy. What matters more is that the person working with you understands both the memories and the patterns they left. If a formal assessment would help, the International Trauma Questionnaire is a short, validated measure for both, and we can use it in the first sessions.
References: Cloitre, M., Garvert, D. W., Brewin, C. R., Bryant, R. A. and Maercker, A. (2013). Evidence for proposed ICD-11 PTSD and complex PTSD: a latent profile analysis. European Journal of Psychotraumatology, 4. World Health Organization (2019). International Classification of Diseases, 11th revision (ICD-11).
