Chapter 6: Post-traumatic Stress Disorder
Over 76% of Canadians report being exposed to a traumatic event at least once in their lifetime. Traumatic events are those that expose someone to actual or threatened death, serious injury, or sexual violence. About 8% of Canadians exposed to a traumatic event will develop post-traumatic stress disorder (PTSD).
Example traumatic events include sexual assault, witnessing domestic or community violence, or military combat.
People with PTSD experience intrusive symptoms such that they re-experience the traumatic event, for example via unwanted memories, nightmares, or flashbacks of the event. These symptoms are not within someone’s control, which can be especially distressing.
PTSD is also marked by avoidance of trauma-related stimuli that might remind the person of the traumatic event(s). People with PTSD engage in this avoidance in order to stay away from the overwhelming fear response that arises when they are around trauma-related stimuli.
Another type of symptom is the negative changes in mood or cognition related to the traumatic event such as an inability to remember important parts of the event, exaggerated negative beliefs about it, negative emotions, and the inability to experience positive emotions.
People with PTSD also experience significant changes in arousal and behaviour such as irritability, hypervigilance, and sleep disturbances. This overarousal sometimes results in them feeling tense, “keyed up,” or on edge. It is also common for people with PTSD to have exaggerated startle responses, for example to loud unexpected noises.
The DSM-5 has separate diagnostic criteria for children younger than 6. Some important differences are that in young children intrusive memories might be expressed through repetitive play.
Event centrality refers to how central we come to see a traumatic event to our lives, memories, and identities. The centrality of events scale measures the extent to which a memory for a traumatic event becomes a reference point for one’s identity, life story, and the attribution of meaning to other experiences.
According to the autobiographical memory model of PTSD, symptoms result from the over integration of the trauma into one’s memory, identity, and understanding of the world. Event centrality is positively associated with PTSD.
Interpersonal traumatic events that are purposefully caused by other people are most likely to lead to PTSD. Social support helps people to effectively manage their emotions, and it is central both for preventing the onset of PTSD and for helping with recovery.
The American Psychological Association (APA) has developed a list of empirically supported treatments for PTSD. They divide them into strongly recommended treatments and conditionally recommended treatments, based on how convincing the research is to support them.
Strongly recommended treatments for PTSD include several versions of cognitive behavioural therapy (CBT) including Prolonged Exposure (PE) and Cognitive Processing Therapy (CPT). Conditionally recommended treatments including Eye Movement Desensitization and Reprocessing Therapy (EMDR), Narrative Exposure Therapy, and medication.