Post Traumatic Stress Disorder Flashcards
• Symptoms and criteria for PTSD • Review of implicated brain areas and neuroimaging studies of PTSD • The role of the HPA – an endocrine system that involves the hypothalamus! • The role of hippocampal volume • Using PTSD as an example of the difficulty disentangling a risk factor vs an acquired effect of having experienced an event/having condition (not a unique issue to PTSD) • Examining neurobiological models for PTSD treatment
When was PTSD originally defined in DSM-III?
1980
What was PTSD originally known as?
“Soldier’s Heart”, “Shell Shock”, “Battle Fatigue”, “Delayed Stress”
What is a key problem surrounding PTSD?
There are many people who experience traumatic events who do not go on to develop PTSD (why do some people respond to trauma in ways that other’s don’t)
It’s normal to experience upsetting/confusing thoughts after a traumatic event… but in most people these improve naturally over a few weeks. However, symptoms/criteria for PTSD include:
▪ A stressor event (the ‘trauma’)
▪ Intrusion symptoms
▪ Alterations in arousal/reactivity
▪ Negative alterations in cognition/mood
▪ Avoidance behaviours
what is ‘complex’ PTSD?
trauma episode is related to multiple events over an extended period of time (i.e. abuse), rather than a single traumatic event/short series of events
What is the criteria for PTSD?
▪ Stressor
▪ Alteration in arousal and reactivity
▪ Intrusion Symptoms
▪ Negative alterations in cognition/mood
▪ Avoidance
What criteria must symptoms hit before it can be diagnosed as PTSD?
Symptoms last for more than a month. Symptoms create distress or functional impairment (e.g. social, occupational). Symptoms are not due to medication, substance use or other illness
What are stressors?
Person exposed to: death, threatened death, actual or threatened serious injury, or actual or threatened sexual violence, via…
▪ Direct exposure (happens to them)
▪ Witnessing the trauma (seeing somebody experience the event)
▪ Learning relative/close friend was exposed to a trauma
▪ Indirect exposure to aversive details of trauma (e.g., first responders, medics) – remember everyone’s meaning of trauma is different
what are alterations in arousal and reactivity?
Trauma-related arousal and reactivity began or worsened after trauma:
▪ Irritability or aggression
▪ Risky or destructive behaviour
▪ Hypervigilance
▪ Heightened startle reaction
▪ Difficulty concentrating
▪ Difficulty sleeping
What are intrusion symptoms?
Traumatic event persistently re-experienced via…
▪ Unwanted upsetting memories
▪ Nightmares
▪ Flashbacks
▪ Emotional distress after exposure to reminders
▪ Physical reactivity after exposure to reminders
What is negative alterations in cognition
Negative thoughts/feelings began or worsened after trauma:
▪ Inability to recall key features of the trauma (issues with recall in trauma)
▪ Overly negative thoughts/assumptions about oneself/the world
▪ Exaggerated blame of self or others for causing the trauma
▪ Negative affect
▪ Decreased interest in activities
▪ Feeling isolated
▪ Difficulty experiencing positive affect
What is avoidance?
Avoidance of trauma-related stimuli after the trauma, in the following way(s):
▪ Trauma-related thoughts or feelings
▪ Trauma-related external reminders
This means they’re avoiding specific traumas in terms of locations but also thoughts and feelings
Complex neurobiology of PTSD:
Prefrontal cortex (Dorsolateral PFC and Orbitofrontal Cortex (/Ventromedial PFC))
Cingulate cortex (Anterior cingulate cortex)
Limbic regions (Thalamus (not specifically PTSD but characterises anxiety disorder more generally), Amygdala (not specifically PTSD but characterises anxiety disorder more generally) and Hippocampus)
Neuroendocrine system (the HPA)
Amygdala:
▪ Part of the limbic system
▪ Involved in emotion processing (of all kinds)
▪ Component of the reward, motivation and learning networks
▪ Stimulates the HPA
The link between the amygdala and PTSD:
▪ PTSD Veterans, Combat Veterans and controls scanned with PET (metabolic measure of blood flow and energy use within the brain)
▪ Played white noise and combat sounds
▪ PTSD veterans showed a greater physiological responses: stress and skin response to combat noise than white noise
▪ PTSD veterans showed a greater response to combat noise in left amygdala
▪ Combat sound more distressing to PTSD sample than non-combat control and regular control
▪ Combat controls show heightened amygdala responses, but only slightly when combat sounds are played
▪ Whereas, those with PTSD showed a much greater response in the left amgdala when combat sounds were played compared to white noise
why can’t you use fMRI scanners with soldiers?
magnets are dangerous when soldiers potentially still have metal in them etc. from previous wombs so instead PET scans are preferred in this circumstance
Cingulate Cortex
▪ ACC = Anterior cingulate cortex
▪ Involved in attention, reward, decision making and emotion
▪ Part of frontal-striatal network
▪ Also part of the “salience network” (sometimes called ventral attention network) à involved in alerting attention to threats/unexpected stimuli/changes to our environment
Heterogeneity in PTSD treatment responses related to ventral attention network (Etkin et al., 2019)
▪ Resting-state fMRI study of PTSD patients and controls
▪ Reports rsfMRI connectivity of brain networks and cognitive testing
▪ Results show PTSD patients with poor verbal memory and weak connectivity in ventral attention network (pink) had poorer treatment response
▪ Shows neural and cognitive factors that impair treatment
▪ Found PTSD patients with poorer connectivity in VAN had poorer response and poor verbal memory - potentially a biomarker for poor treatment response