3.9.5 Post-traumatic stress disorder
Post-Traumatic Stress Disorder
Post-Traumatic Stress Disorder (PTSD) is a mental health condition that can occur after a person experiences or witnesses a traumatic event, such as combat, natural disasters, sexual assault, or physical violence. The condition is characterized by a persistent re-experiencing of the traumatic event through flashbacks, intrusive thoughts, or nightmares, as well as avoidance behaviours and emotional numbing, and symptoms of hyperarousal, such as irritability, sleep disturbances, and hypervigilance (APA, 2013).
PTSD has been widely studied and documented in various populations, including veterans, survivors of natural disasters and sexual assault, and individuals who have experienced physical violence. Prevalence rates of PTSD vary depending on the population studied and the methods used for assessment, but it is estimated that approximately 7-8% of the general population will experience PTSD at some point in their lifetime (Kessler, 2005).
The exact causes of PTSD are not well understood, but it is believed to be related to a complex interaction of biological, psychological, and social factors. Neurobiological research has shown that individuals with PTSD have changes in the structure and function of the brain, including alterations in the amygdala, hippocampus, and prefrontal cortex, which are important for regulating emotions and memories (Shin, 2005).
Treatment for PTSD typically involves a combination of psychotherapy and medication. Cognitive behavioural therapy (CBT) and exposure therapy have been shown to be effective in reducing symptoms of PTSD, by helping individuals process the traumatic event and reducing their avoidance of reminders of the event (Foa, 2005). Antidepressant medication, such as selective serotonin reuptake inhibitors (SSRIs), can also be helpful in reducing symptoms of anxiety and depression associated with PTSD (Bryant, 2014).
In summary, PTSD is a debilitating condition that can occur following exposure to a traumatic event. While the exact causes of PTSD are not well understood, research has shown that a combination of biological, psychological, and social factors contribute to the development of the disorder. Effective treatments for PTSD include psychotherapy and medication, with CBT and exposure therapy being among the most widely studied and effective treatments for the condition.
Symptoms:
Post-traumatic stress disorder symptoms can begin as soon as one month after a stressful experience, but they can also take years to manifest. Significant issues are brought on by these symptoms in social, professional, and romantic interactions. They may also make it difficult for you to carry out regular activities as usual.
Intrusive memories, avoidance, unfavourable changes in thought and attitude, and changes in bodily and emotional reactions are the four main categories of PTSD symptoms. The severity of symptoms can change over time or from person to person.
Neurobiology of PTSD
The neurobiological features of PTSD can be broken down into neuroanatomy, neuroendocrine, and neurochemical:
| Neuroanatomy: | Change: | Effect: |
| Amygdala | Increased activity | Increased hypervigilance Decreased discrimination of threat |
| Cortex | i) Decreased prefrontal volume ii) Decreased anterior cingulate volume iii) Decreased medial prefrontal activation | i) Dysregulates executive functions ii) Impairs the extinction of fear responses iii) Unclear |
| Hippocampus | Decreased volume and activity | Alters stress responses and extinction |
| Neuroendocrine: | Change: | Effect: |
| Hypothalamic-pituitary-adrenal axis | Hypocortisolism | Abnormal stress encoding and fear processing Disinhibited CRH/NA and upregulated response to stress |
| Hypothalamic-pituitary-thyroid axis | Abnormal T3:T4 ratio | Increased level of subjective anxiety |
| Neuroendocrine: | Change: | Effect: |
| Catecholamines | Increased dopamine Increased noradrenaline | Interferes with fear conditioning via the mesolimbic system Increased arousal and startle responses Increased physiological responses to memories |
| Serotonin | Decreased serotonin in the raphe nucleus | The disturbed dynamic between the amygdala and hippocampus |
(Sherin, 2011)
DSM vs ICD
The criteria for the diagnosis of Post-Traumatic Stress Disorder (PTSD) in the DSM-5 and ICD-11 are similar but have some differences.
The DSM-5 criteria for PTSD require the presence of a traumatic event, followed by the development of specific symptoms including intrusive thoughts and memories of the traumatic event, avoidance of reminders of the event, negative changes in thoughts and feelings, and symptoms of hyperarousal. The symptoms must persist for more than one month and cause significant distress or impairment in functioning to be considered PTSD (American Psychiatric Association, 2013).
The ICD-11 criteria for PTSD require the presence of a traumatic event and the development of specific symptoms, including re-experiencing the traumatic event through flashbacks or intrusive thoughts, avoidance of reminders of the event, negative changes in mood and cognition, and symptoms of hyperarousal. The symptoms must persist for more than one month and cause significant distress or functional impairment to be considered PTSD (World Health Organization, 2019).
The main difference between the DSM-5 and ICD-11 criteria is the number of symptoms required for diagnosis. The DSM-5 requires the presence of at least one symptom from each of the four symptom clusters (intrusive thoughts, avoidance, negative changes in mood and cognition, and hyperarousal), while the ICD-11 requires the presence of at least one re-experiencing symptom, at least one avoidance symptom, and at least two symptoms from the other two symptom clusters.
A comparison of the DSM-5 and ICD-11 criteria for PTSD is presented in the table below:
| DSM-5 Criteria for PTSD: | ICD-11 Criteria for PTSD: |
|---|---|
| Traumatic event | Traumatic event |
| Intrusive thoughts and memories of the traumatic event | Re-experiencing the traumatic event through flashbacks or intrusive thoughts |
| Avoidance of reminders of the traumatic event | Avoidance of reminders of the traumatic event |
| Negative changes in thoughts and feelings | Negative changes in mood and cognition |
| Symptoms of hyperarousal | Symptoms of hyperarousal |
| Symptoms must persist for more than one month | Symptoms must persist for more than one month |
| Significant distress or impairment in functioning | Significant distress or functional impairment |
| At least one symptom from each of the four symptom clusters | At least one re-experiencing symptom, at least one avoidance symptom, and at least two symptoms from the other two symptom clusters |
References:
(1) American Psychiatric Association (APA). (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.
(2) Bryant, R. A., Sackville, T., Dang, S. T., Moulds, M., & Guthrie, R. (2014). Treating acute stress disorder: An assessment of the evidence. Australian & New Zealand Journal of Psychiatry, 48(3), 187-194.
(3) Foa, E. B., Keane, T. M., & Friedman, M. J. (Eds.). (2000). Effective treatments for PTSD: Practice guidelines from the International Society for Traumatic Stress Studies. New York, NY: Guilford Press.
(4) Kessler, R. C., Chiu, W. T., Demler, O., Merikangas, K. R., & Walters, E. E. (2005). Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62(6), 617-627.
(5) Sherin, J.E. and Nemeroff, C.B. (2011). Post-traumatic stress disorder: the neurobiological impact of psychological trauma. Dialogues in clinical neuroscience, [online] 13(3), pp.263–78. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3182008/.
(6) Shin, L. M., Rauch, S. L., & Pitman, R. K. (2006). Amygdala, medial prefrontal cortex, and hippocampal function in PTSD. Annals of the New York Academy of Sciences, 1071, 67-79.
(7) World Health Organization. (2019). International Classification of Diseases, 11th Revision (ICD-11). Geneva, Switzerland: World Health Organization.