DSM-5: PTSD
PTSD first appeared as an official diagnosis in DSM III (1980) => Prior to this: DSM I: “Gross Stress Reaction”, DSM II: “Transient Situation Disturbances”
Emerged in DSM as a response from social movements in the 1970s => Women’s movement, War veterans, Holocaust survivors
Departure from other DSM categories:
- Trauma is the presumed common etiological factor
- Disorder is organized around it *Highly controversial
Criteria:
- Need exposure to a traumatic event
- Intrusion symptoms ex: intrusive memories, dreams, flashbacks
- Avoidance symptoms ex: trauma-related thoughts and external reminders
- Negative alterations of cognitions and mood ex: memory impairment, negative beliefs and emotions, detachment from others
- Arousal and reactivity ex: angry outbursts, hypervigilance, exaggerated startle response
- Duration: > 1 month
Other DSM-5 Dx
Acute Stress Disorder
- Same symptoms as PTSD BUT duration of symptoms is
less than one month
Course:
- Can be transient (i.e., remit after one month)
- Or can progress into PTSD (or other diagnosis)
Adjustment Disorder
- Emotional and behavioral disturbance occurring within 3 months of onset of the stressor
- More common stressors (e.g., business or marriage problems) => Should this even be a disorder?
Controversies
1- No Longer An Anxiety Disorder => PTSD was relocated out of the Anxiety Disorders chapter and into a to a new diagnostic category
- Argued that PTSD has non-anxiety symptoms: Dissociative experiences, Anger, guilt, shame
- But fear conditioning seems to be similar underlying process
2- What constitutes a trauma?
Normal response to abnormal event? Abnormal response to normal, stressful event?
- In DSM III – event had to be outside the range of “usual human experience” => Emphasis on nature of stressor
- What events are outside the range of normal human experience? Focused on rape, earthquakes, torture, military combat => But these can be common in some places
- Can PTSD result from events in normal range? ex: car accident
- DSM IV got rid of “normal human experience” concept => Shift toward abnormal response to a normal event (“Conceptual bracket creep”)
- DSM 5 focused on tightening criteria ex: Need “in person” experience (not through electronic media), Need actual/threatened death/injury (Not stressful life event ex: divorce)
3- Normal vs Abnormal Event?
Recent studies have looked at rates of PTSD following: Traumas (meeting DSM Criterion A), Stressful life events (not necessarily traumatic)
- Do you need a full-blown trauma for PTSD? => Rates of PTSD symptoms were higher after life stressors than for traumas
4- PTSD and Depression
- Depression is as likely an outcome following a trauma as PTSD => Stress is a risk factor for depression too
- Close relationship between PTSD and
depression: High comorbidity, Predict one another - Are they separate disorders, or do they have a common diathesis?
5- Political and Financial Interests
- Controversy that PTSD diagnosis services political and financial purpose, rather than clinical one => Veterans Administration now required to provide services
- Methodological Issue: Research on PTSD is often done on people with a vested interest in being diagnosed with PTSD ex: Study found lower PTSD rates among war veterans when assessed via clinical interview (4%) rather than questionnaire (21%)
- Some studies have tried to verify trauma histories of people => 93% of Vietnam vets with PTSD had actually been in Vietnam and from those Over 1⁄2 had no documented combat exposure
- 7% had never been in Vietnam or never been in the military
Epidemio
Prevalence rates following trauma
DSM-III: PTSD thought to be rare (3%) vs Now: Lifetime prevalence: 6.8% => But traumatic events are relatively common
- Study found that 85% of undergrad students experienced a traumatic event in their lifetime => following trauma, 9% develop PTSD
*Traumatic event is necessary but not sufficient cause of PTSD
Gender diff => 2F: 1M
Are women more likely to experience traumatic event? => No men report more trauma (1st criterion) vs women
So, why are women less likely to have trauma but more likely to develop PTSD?
Difference in types of traumatic experiences
- Men: accidents, nonsexual assault, combat/war, disaster, fire, serious illness, witnessing death/injury
- Women: sexual assault, child sexual abuse => These events are more likely to contribute to the development to PTSD *Implication of human intent
BUT
- Higher prevalence of PTSD among women is not solely attributed to differences in event types
- Even when exposed to the same traumatic event, PTSD rates are higher in women ex: Oklahoma City bombing with 45% women vs. 23% men reported PTSD symptoms
Cross-Cultural Studies
Variability in PTSD rates across cultures => Highest in Canada
Why? Violation of expectations of safety
But, symptoms vary across cultures => “Flashbacks” may be a Western phenomenon, More somatic presentation in other cultures
Risk Factors
Pre-Trauma Risk Factors => Who is more likely to experience trauma?
- Gender (male)
- Occupations (ex: first responders)
- Familial psychopathology
- Pre-existing psychopathology (ex: depression)
- Childhood adversity (ex: abuse)
- Low SES
- Low education
- Race (Black > White)
Post-Trauma Risk Factors => Who is more likely to develop PTSD after experiencing a trauma?
Individual Differences:
- Gender (female)
- Pre-existing psychopathology
- Lack of social support
- Lower IQ => can make meaning in adapting way
Nature of Trauma
- Proximity (to you or sme else)
- Duration
- Level of life risk
- Human involvement
- Intention ex: assault vs. accident
- Psychological processes occurring during and after trauma
- Dissociation
Biological Factors
Vietnam twin registry
- Among twins who both served, 33% of variance due to genetics (controlling for combat exposure)
- Same registry: Identical twins, one served and one didn’t => Twin who served in Vietnam much more likely to have PTSD than those who did not
*Evidence for genetic factors as well as environmental events
Hippocampus: Involved in explicit memory processes and encoding of context during fear conditioning
- Hippocampal volumes are reduced in size in brains of people with PTSD => Smaller hippocampal volume associated with greater symptom severity (e.g., chronic, unremitting PTSD)
Scar => Most of this research is cross-sectional (correlational)
- Are brain abnormalities observed in PTSD caused by the trauma? If so, represents a “scar” of the trauma on the brain
=> Ample evidence from animal research that severe stress can damage the hippocampus
BUT correlation does not equal causation *Not everyone who experiences even severe acute stressors goes on to develop PTSD *In fact, majority do not (Also, evidence that hippocampal volume is heritable)
=> Possible alternative explanation: Brain abnormality might be vulnerability factor to developing PTSD?
*Prospective Designs: To tackle cause/effect questions, measure biological factor in individuals prior to traumatic event and again afterwards BUT, difficult to do this
Twins Discordant Study
Identify surrogates for what the trauma- exposed person would be like if they didn’t have the experience of the traumatic event
Non-trauma exposed, identical (MZ) twin => Shares all the genes of the trauma-exposed twin, shares a lot of twin’s early developmental environment (ex: same family, community, school) BUT Non-shared environment = trauma experience (unique to exposed twin)
Study: All male; in their early 50s
- 17 combat-exposed Vietnam veterans with PTSD (ExP+)
- 17 non-combat-exposed co-twins of ExP+ (UxP+)
- 23 combat-exposed Vietnam veterans with no PTSD (ExP-)
- 23 non-combat-exposed co-twins of ExP- (UxP-)
=> Examined hippocampal volumes in each of the four groups
If HC volume is a “scar” of trauma, we would expect differences between ExP+ and UxP+
If HC volume is a vulnerability factor for PTSD, we would expect NO difference between ExP+ and UxP+
Results brain volume correl with PTSD Sx:
- ExP+ subjects have a negative relationship between HC volume and PTSD symptom severity
- UxP+ subjects’ HC volume ALSO predicts the severity of their exposed co- twins symptoms (twin didn’t combat able to predict their co-twin sx)
- Combat severity not associated with HC volume
Results brain volume diff in twin pair gr:
- PTSD group has less HC volume compared to those without PTSD (10% difference)
- But HC volumes are smaller in BOTH ExP+ and UxP+ twins (no difference!)
CONCLUSIONS:
- Smaller hippocampal volume in PTSD may represent a pre-existing, familial vulnerability* Doesn’t seem to be a “scar” of trauma
- Combat exposure and hippocampal volume may represent independent risk factors
Psychological Factors
Traumatic Memories
Differences in the way that memories may be stored and retrieved
- Traumatic: non-verbal, sensory-form
- Non-traumatic: verbal form
=> Sensory impressions are experienced as if they are happening in the here-and- now, rather than memories from past (Can explain why talking about trauma in therapy is beneficial)
Cognitive Theory
PTSD becomes persistent when individuals process the trauma in a way that leads to a sense of serious, current threat
- Negative appraisals about the traumatic event
- Disturbance in autobiographical memory =>
PTSD patients have difficulty intentionally retrieving memory BUT, have high frequency of involuntarily triggered intrusive memories
- Poor memory elaboration: Memory is not adequately integrated into context => Hypothesized to be related to dissociation
- Strong associative memory for traumatic stimuli (conditioned stimulus strong) => Also, strong link with stimuli presented before/during traumatic event
- Strong perceptual priming for stimuli temporally associated with the traumatic event ex: tall man
Treatment
Prevention-focused strategies
- Reduce likelihood of trauma
- Increase coping skills (ex: stress inoculation training)
Crisis Intervention
- Psychological first aid
- Debriefing (ex: listening, engage, connect )
Cognitive-Behavioral Therapies*
- Prolonged exposure
- Cognitive reprocessing therapy
