Post-Traumatic Stress Disorder

Definition

PTSD requires exposure to a qualifying event plus symptoms across four clusters in DSM-5:

• Intrusion: involuntary memories, nightmares, flashbacks.
• Avoidance of reminders, internal or external.
• Negative alterations in cognition and mood: persistent negative beliefs, distorted blame, detachment.
• Alterations in arousal and reactivity: hypervigilance, startle, sleep disturbance, irritability.

Symptoms must last more than a month and cause impairment. ICD-11 takes a narrower approach, requiring only re-experiencing in the present, avoidance and sense of current threat, and adds a separate Complex PTSD diagnosis.

History

The condition has been described repeatedly under different names — soldier's heart, shell shock, combat fatigue — and repeatedly forgotten between wars.

It entered DSM-III in 1980, driven substantially by advocacy around Vietnam veterans, and its criteria have been revised in every edition since. The DSM-5 revision removed the requirement that the person respond with fear, helplessness or horror, which had excluded people who responded with numbness or nothing at all.

Theory

Two frameworks dominate.

Emotional processing / fear network accounts hold that the traumatic memory is stored as a network of stimulus, response and meaning elements that is easily activated and resists modification, and that treatment works by activating and modifying it.

Cognitive models, particularly Ehlers and Clark, hold that PTSD persists when the person processes the trauma in a way that produces a sense of current threat: an unelaborated, poorly contextualised memory plus negative appraisals plus maintaining behaviours such as rumination, thought suppression and safety behaviours.

The cognitive model has the advantage of explaining why the disorder persists rather than only why it starts.

Research

Most people exposed to trauma do not develop PTSD. Lifetime prevalence in the general population is commonly estimated around 4 to 8 percent, with higher rates after interpersonal and sexual violence than after accidents or disasters.

Trauma-focused psychological treatments — prolonged exposure, cognitive processing therapy, cognitive therapy for PTSD, EMDR — have the strongest evidence and are recommended ahead of medication in most guidelines.

Psychological debriefing immediately after trauma does not help and may cause harm. This is one of the clearest negative findings in clinical psychology and it took a long time to change practice.

Applications

Assessment usually combines a structured interview with a self-report measure. Trauma-focused treatment is first line; SSRIs have evidence but smaller effects.

Comorbidity is the norm rather than the exception, particularly depression and substance use, and treating PTSD often improves both.

Criticism

• The criterion A problem. What counts as a qualifying trauma has expanded and contracted across editions, and the boundary is not principled. Similar symptom profiles follow events that do not qualify.
• Symptom combinations. The DSM-5 criteria can be met by a very large number of different symptom combinations, so two people with the same diagnosis may share almost nothing.
• Complex PTSD is contested. ICD-11 recognises it, DSM-5 does not, and whether it is a distinct condition or PTSD plus comorbidity remains argued.
• Cultural specificity. The construct was developed in Western clinical settings, and expressions of post-traumatic distress elsewhere do not always map onto it.

References

• Ehlers, A., & Clark, D. M. (2000). A cognitive model of posttraumatic stress disorder. Behaviour Research and Therapy, 38(4), 319-345.
• Foa, E. B., & Kozak, M. J. (1986). Emotional processing of fear. Psychological Bulletin, 99(1), 20-35.
• Rose, S., et al. (2002). Psychological debriefing for preventing PTSD. Cochrane Database of Systematic Reviews.
• Galatzer-Levy, I. R., & Bryant, R. A. (2013). 636,120 ways to have posttraumatic stress disorder. Perspectives on Psychological Science, 8(6), 651-662.