What is PTSD?

Post-Traumatic Stress Disorder or PTSD is a term used to describe experiences that can occur after a traumatic event. Traumatic events involve directly experiencing, witnessing or hearing about severe physical or psychological harm, and are often accompanied by an intense emotional and physiological response. Examples of such events include natural disasters, accidents, rape, bullying, and childhood sexual abuse. Not everyone who experiences a traumatic event will develop PTSD. 

People with PTSD often feel anxious, panicked, on edge and angry, particularly when they encounter a reminder of their trauma. There is frequently a strong physical response to these reminders, such as sweating and a racing heart. Often the emotional and physiological response is similar to when the person originally experienced the trauma. People with PTSD may also experience nightmares and flashbacks, in which they re-experience the trauma, so that it feels as though it is happening again in the present. They may avoid certain situations, people and places that they associate with the trauma, and they may block out thoughts, memories and emotions linked to the trauma. People with PTSD often have difficulties with sleep. 

The PCL-5 is a 20-item checklist that can help assess whether someone has PTSD: https://www.ptsd.va.gov/professional/assessment/documents/PCL5_Standard_form.PDF

‘Complex PTSD’ is characterised by the symptoms of PTSD, alongside difficulties in relationships, a negative view of oneself, and the experience of intense and overwhelming emotions. Chronic or repeated trauma, such as prolonged domestic violence, is a risk factor for complex PTSD.

Who does it affect?

A 2014 study of adults in England found that 3.7% of men and 5.1% of women met criteria for PTSD, with the highest prevalence (12.6%) among females aged 16 to 24. Meanwhile, a 2019 study of the general population in the US found that 7.2% met criteria for PTSD or complex PTSD, with 3.4% reporting symptoms consistent with PTSD and 3.8% having difficulties associated with complex PTSD. In the latter study, women were more likely than men to meet criteria for both disorders.

What causes it?

PTSD is caused by experiencing, witnessing or –  less commonly – hearing about one-off, repeated or multiple traumatic events. Research suggests you are more likely to develop PTSD if you have pre-existing depression, lack social support, or are exposed to high levels of stress in your environment. The evidence also suggests that PTSD is more likely when the traumatic event is unexpected, lasts a long time, involves being trapped, is caused by people, results in many deaths, damages the body, or involves children. It appears that experiential avoidance – attempts to block unwanted thoughts, emotions, memories and sensations – prior to a traumatic event, and dissociation –being detached from one’s body or the world around – during a traumatic event, are risk factors for developing PTSD. According to a number of trauma theories, the overwhelming nature of traumatic events interferes with processing the experience and encoding it in memory. There is evidence that principally processing sensory information, rather than the meaning and context of the event, during a traumatic experience increases the risk of PTSD. Studies have shown that genes influence susceptibility to developing PTSD. It has also been established that the brains of those with PTSD differ from those without PTSD; however, it is not clear if these differences – such as those with PTSD having a smaller ‘hippocampus’, on average – are risk factors for, or consequences of, PTSD. 

How can I help myself?

If you are living with PTSD, it can be helpful to identify the situations, people and places that trigger your flashbacks or nightmares because this can empower you to plan ahead and look after yourself. 

Grounding strategies, which help people connect to the present and increase their sense of safety, include having a cold drink of water, looking at a recent photo of yourself, counting objects in the room around you, and touching something nearby  such as the arms of a chair.

It is also helpful to try to look after your physical health, including ensuring you are eating a well-balanced diet, getting enough exercise, attending medical appointments, and avoiding illicit drugs and alcohol. Maintaining your usual routine and activities, and having social contact, is likely to improve your wellbeing and reduce your vulnerability to anxiety and depression following a traumatic experience.

Further information, including self-help advice, can be accessed via the following links:

What if I need more help?

There are a number of evidence-based treatments for PTSD, including Trauma-Focused Cognitive Behavioural Therapy (CBT) and Eye Movement Desensitisation and Reprocessing therapy (EMDR). Trauma-focused therapies often have a stabilisation stage and then a trauma-processing stage. The purpose of the stabilisation stage is to ensure the person is equipped to manage the difficult process of revisiting their trauma. The purpose of revisiting the trauma is to assist in the processing of the memories and thereby reduce the experience of flashbacks, nightmares, and other symptoms. The most appropriate therapy depends on the individual’s presenting needs and goals, and would be explored in an initial assessment.

If you feel that you have PTSD or complex PTSD and would like to access support, you can speak to your GP about local options within the NHS. You may also be able to self-refer to your local Improving Access to Psychological Therapy (IAPT) service; these services often provide trauma-focused therapy and are free to access. Trauma-focused therapy is also offered privately at a cost, with fees determined by individual practitioners.

You may be eligible to register with AnonyMind for access to free sessions with clinicians trained to treat PTSD.


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Cloitre, M. (2019). WHO ICD-11 Complex PTSD foundations and diagnosis. Complex Trauma Conference.

Cloitre, M., Hyland, P., Bisson, J. I., Brewin, C. R., Roberts, N. P., Karatzias, T., & Shevlin, M. (2019). ICD‐11 posttraumatic stress disorder and complex posttraumatic stress disorder in the United States: A population‐based study. Journal of Traumatic Stress, 32(6), 833-842.

Halligan, S. L., Clark, D. M., & Ehlers, A. (2002). Cognitive processing, memory, and the development of PTSD symptoms: Two experimental analogue studies. Journal of Behavior therapy and experimental Psychiatry, 33(2), 73-89.

Kumpula, M. J., Orcutt, H. K., Bardeen, J. R., & Varkovitzky, R. L. (2011). Peritraumatic dissociation and experiential avoidance as prospective predictors of posttraumatic stress symptoms. Journal of abnormal psychology, 120(3), 617.

NICE (2020). Post-Traumatic Stress Disorder: How common is it? Retrieved from https://cks.nice.org.uk/topics/post-traumatic-stress-disorder/background-information/prevalence/ on 21/11/2021. 

Pitman, R. K., Rasmusson, A. M., Koenen, K. C., Shin, L. M., Orr, S. P., Gilbertson, M. W., ... & Liberzon, I. (2012). Biological studies of post-traumatic stress disorder. Nature Reviews neuroscience, 13(11), 769-787.

Rethink Mental Illness (2019). Post-Traumatic Stress Disorder factsheet. Retrieved from https://www.rethink.org/advice-and-information/about-mental-illness/learn-more-about-conditions/post-traumatic-stress-disorder-ptsd/?gclid=Cj0KCQiA-eeMBhCpARIsAAZfxZB8_dqn4iiCpcg2mxnbiao2JiwXzDbWn9bglT3w8pUNrSIn4jXwS6IaAtbNEALw_wcB on 21/11/2021.