Trauma and PTSD

Definitions and Core Concepts

Trauma refers to an event, series of events, or set of circumstances that is experienced as physically or emotionally harmful or life-threatening and that has lasting adverse effects on the individual’s functioning and mental, physical, social, emotional, or spiritual well-being (SAMHSA).

Trauma Types

Type	Description	Examples
Acute trauma	Single, time-limited event	Accident, assault, natural disaster, witnessing violence
Chronic trauma	Repeated, prolonged events	Ongoing abuse, domestic violence, war, captivity
Complex trauma	Multiple, varied events, usually interpersonal and early-life	Childhood abuse and neglect, prolonged maltreatment
Vicarious/secondary trauma	Exposure to others’ trauma (professional or personal)	First responders, therapists, family of trauma survivor
Historical/intergenerational	Trauma transmitted across generations through systemic oppression	Genocide, slavery, colonization, forced displacement
Developmental	Trauma occurring during critical developmental periods	Childhood trauma affecting brain development, attachment

Prevalence of Trauma Exposure

Population	Lifetime Trauma Exposure
General population	~50-80%
Refugees	~90%+
Military veterans	~70-90% (combat exposure)
Survivors of interpersonal violence	Variable (higher in certain populations)
First responders	~70-90% (repeated exposure)

Post-Traumatic Stress Disorder (PTSD)

PTSD is a psychiatric disorder that may occur in individuals who have experienced or witnessed a traumatic event involving actual or threatened death, serious injury, or sexual violence.

Epidemiology

Metric	Value
Lifetime prevalence (US)	~6-8%
12-month prevalence (US)	~3-5%
Female:male ratio	2:1
Median age of onset	~23 years
Course	Chronic in ~40% of cases
Remission rate (within 10 years)	~50%
Comorbidity rate	~80% have at least one comorbid disorder

DSM-5 Diagnostic Criteria

Criterion A: Exposure to actual or threatened death, serious injury, or sexual violence in one or more of the following ways:

1. Directly experiencing the traumatic event(s)
2. Witnessing, in person, the event(s) as it occurred to others
3. Learning that the traumatic event(s) occurred to a close family member or close friend (violent or accidental)
4. Experiencing repeated or extreme exposure to aversive details of the traumatic event(s) (professional exposure)

Criteria B-E (Symptoms):

Cluster	Symptom Group	Examples	Number Required
B. Intrusion	Recurrent, involuntary, intrusive memories; traumatic nightmares; flashbacks; intense distress at reminders; physiological reactivity	“I can’t stop seeing it in my mind”	1+
C. Avoidance	Avoidance of trauma-related thoughts, feelings, or external reminders (people, places, activities)	“I don’t go anywhere that reminds me”	1+
D. Negative alterations in cognition and mood	Inability to recall important aspects of trauma; persistent negative beliefs (world is dangerous, self is worthless); distorted blame; persistent negative emotions; loss of interest; detachment; inability to feel positive emotions	“Nothing matters anymore; I feel dead inside”	2+
E. Alterations in arousal and reactivity	Irritable/angry outbursts; reckless/self-destructive behavior; hypervigilance; exaggerated startle; concentration problems; sleep disturbance	“I’m always on guard; every sound makes me jump”	2+

Additional criteria:

• Duration: Symptoms persist for more than 1 month
• Functional impairment: Symptoms cause clinically significant distress or impairment
• Exclusion: Not attributable to substance use or another medical condition

Specifiers

Specifier	Description
With dissociative symptoms (depersonalization)	Experiences of feeling detached from one’s own body, thoughts, or feelings
With dissociative symptoms (derealization)	Experiences of unreality, distance, or distortion of surroundings
With delayed expression	Full diagnostic criteria not met until at least 6 months after the event

PTSD Symptom Subtypes

Phenotypic variation:

Subtype	Dominant Symptoms	Common Characteristics
Externalizing	Anger, irritability, reckless behavior	More common in males; substance use common
Internalizing	Depression, numbing, avoidance	More common in females; comorbid depression
Dissociative	Depersonalization, derealization	Higher trauma severity; early-life trauma
Complex	Affect dysregulation, negative self-concept, relationship difficulties	Chronic, early interpersonal trauma

Acute Stress Disorder (ASD)

Acute stress disorder describes trauma reactions occurring within the first month after exposure.

DSM-5 Criteria

• Exposure to traumatic event (same criteria as PTSD)
• Presence of 9 or more symptoms from any of five categories: intrusion, negative mood, dissociation, avoidance, and arousal
• Symptoms begin or worsen after trauma exposure
• Duration: 3 days to 1 month
• Functional impairment

ASD vs. PTSD

Feature	ASD	PTSD
Timeframe	3 days to 1 month	More than 1 month
Dissociative symptoms	Required (3+ of 5 types)	Specifier only
Predictive of PTSD	~50% of ASD → PTSD	N/A
Treatment	Early intervention may prevent PTSD	Treatment for established disorder

Complex PTSD (C-PTSD)

C-PTSD is recognized in ICD-11 but not as a separate diagnosis in DSM-5 (symptoms captured under PTSD with dissociative features or “other specified trauma- and stressor-related disorder”).

ICD-11 Criteria

C-PTSD includes all core PTSD symptoms plus three additional symptom clusters:

Cluster	Description
1. Affect dysregulation	Difficulty regulating emotions; extreme emotional responses; emotional numbing
2. Negative self-concept	Feelings of worthlessness, shame, guilt; belief of being different or damaged
3. Disturbances in relationships	Difficulty sustaining relationships; distrust; difficulty feeling close to others

Risk Factors for C-PTSD

• Early-onset, prolonged, or repeated trauma
• Interpersonal trauma (especially by caregivers)
• Enmeshment in traumatic relationships (captivity, abuse)
• Lack of protective factors (social support, resources)

Risk and Protective Factors

Pretraumatic Factors

Domain	Risk Factors	Protective Factors
Demographic	Female sex, younger age, lower socioeconomic status	Higher education, stable resources
Psychiatric	Prior trauma, prior mental disorder, family history	Good prior functioning, adaptive coping
Personality	Neuroticism, negative affectivity, external locus of control	Resilience, optimism, self-efficacy
Cognitive	Lower IQ, lower cognitive flexibility	Higher cognitive reserve
Developmental	Childhood adversity, insecure attachment	Secure attachment, supportive family

Peritraumatic Factors

Factor	Description
Trauma severity	Dose-response relationship: more severe trauma → higher PTSD risk
Perceived threat	Higher perceived life threat → increased risk
Peritraumatic dissociation	During-trauma dissociation predicts later PTSD
Nature of trauma	Interpersonal violence > accidents > natural disasters
Moral injury	Events violating moral beliefs increase complexity
Physical injury	Traumatic brain injury, severe injury increase risk
Lack of social support	Not having support available after trauma increases risk

Posttraumatic Factors

Factor	Effect on PTSD
Social support	Strong protective factor; predicts recovery
Ongoing life stress	Increases risk of chronic PTSD
Maladaptive coping	Avoidance, substance use → worse outcomes
Adaptive coping	Approach-oriented coping → better outcomes
Secondary stressors	Legal, medical, financial stressors compound trauma
Negative social reactions	Blame, disbelief from others worsens outcomes

Neurobiology of PTSD

Brain Structure and Function

Region	Changes in PTSD	Functional Impact
Amygdala	Hyperreactivity	Increased threat detection; persistent fear
Prefrontal cortex (vmPFC, ACC)	Hypofunction; reduced volume	Impaired extinction; poor emotion regulation
Hippocampus	Reduced volume	Contextual memory deficits; difficulty discriminating threat/safety
Insula	Altered function	Increased interoception; somatic symptoms

Neuroendocrine System

System	Alteration	Effect
HPA axis	Low cortisol (some findings); enhanced negative feedback	Altered stress response; immune changes
Norepinephrine	Elevated levels; increased sensitivity	Hyperarousal; intrusive memories; exaggerated startle
Serotonin	Dysregulation	Mood symptoms; impulsivity
Endogenous opioids	Dysregulation	Emotional numbing; dissociation

Fear Conditioning and Extinction

PTSD can be understood as a disorder of fear learning:

• Fear conditioning: Neutral cues present during trauma become conditioned stimuli that trigger fear
• Fear generalization: Broadening of triggers beyond original trauma cues
• Impaired extinction: Difficulty learning that previously threatening cues are now safe (vmPFC dysfunction)
• Contextual processing deficits: Failure to recognize safety contexts (hippocampal dysfunction)

Evidence-Based Treatments

First-Line Psychological Treatments

Prolonged Exposure (PE):

Component	Description
Psychoeducation	Understanding trauma reactions, treatment rationale
Breathing retraining	Calming skill for managing distress
In vivo exposure	Systematic, repeated confrontation with safe but avoided situations
Imaginal exposure	Repeated recounting of trauma memory
Processing	Discussion of thoughts, feelings following exposure
Duration	8-15 sessions, typically 90 minutes

Cognitive Processing Therapy (CPT):

Component	Description
Psychoeducation	Impact of trauma, the role of beliefs
Identify stuck points	Maladaptive beliefs maintaining PTSD (self-blame, distrust, powerlessness)
Socratic questioning	Examining evidence for and against stuck points
Written accounts	Writing impact statement and full trauma account (some versions)
Cognitive worksheets	Structured practice in challenging maladaptive cognitions
Themes	Safety, trust, power/control, esteem, intimacy
Duration	12 sessions, typically 60 minutes

Eye Movement Desensitization and Reprocessing (EMDR):

Component	Description
History taking	Assessment, treatment planning
Preparation	Stabilization, resource development, informed consent
Assessment	Identify target memory, negative cognition, positive cognition
Desensitization	Bilateral stimulation (eye movements, taps, tones) while focusing on trauma memory
Installation	Strengthening positive cognition
Body scan	Processing residual physical tension
Closure	Stabilization at end of each session
Reevaluation	Assessing progress at subsequent sessions
Duration	Variable, typically 8-12 sessions

Trauma-Focused Cognitive Behavioral Therapy (TF-CBT):

• Primarily for children and adolescents
• Components (PRACTICE): Psychoeducation, Parenting skills, Relaxation, Affect regulation, Cognitive processing, Trauma narrative, In vivo exposure, Conjoint sessions, Enhancing safety

Other Psychological Treatments

Treatment	Evidence	Description
Brief Eclectic Psychotherapy	Moderate	Psychodynamic + CBT + creative therapy
Narrative Exposure Therapy	Strong (refugees)	Short-term for survivors of organized violence
STAIR Narrative Therapy	Moderate	Skills training + trauma narrative (complex trauma)
Dialectical Behavior Therapy (DBT)	Moderate (C-PTSD)	Emotion regulation, distress tolerance, interpersonal skills + trauma processing
Present-Centered Therapy	Moderate	Focus on current life problems rather than trauma
Acceptance and Commitment Therapy	Emerging	Values-based action, defusion from trauma-related thoughts

Pharmacotherapy

Medication	Recommendation Level	Notes
Sertraline (SSRI)	First-line	FDA-approved
Paroxetine (SSRI)	First-line	FDA-approved
Fluoxetine (SSRI)	First-line	Strong evidence
Venlafaxine (SNRI)	First-line	FDA-approved
Prazosin	Second-line	Trauma nightmares, sleep disturbance (mixed evidence)
Quetiapine (atypical antipsychotic)	Second-line	Adjunctive; sleep, re-experiencing
Topiramate (anticonvulsant)	Second-line (limited)	May reduce re-experiencing
Benzodiazepines	Not recommended (or caution)	May worsen or interfere with recovery
Propranolol (beta-blocker)	Investigational	Early post-trauma to prevent consolidation (mixed)

Treatment Guidelines Summary

Organization	First-Line	Second-Line	Not Recommended
APA (2023)	PE, CPT, EMDR, TF-CBT	Brief eclectic, narrative exposure	Benzodiazepines
ISTSS (2018)	PE, CPT, EMDR, TF-CBT	SSRIs/SNRIs	Benzodiazepines
VA/DoD (2017)	PE, CPT, EMDR	SSRIs, SNRIs; present-centered therapy	Benzodiazepines
NICE (2018)	TF-CBT, EMDR	SSRIs, SNRIs	Benzodiazepines

Post-Traumatic Growth (PTG)

Post-traumatic growth is the experience of positive psychological change following trauma. Domains include:

Domain	Description	Examples
Greater appreciation of life	Enhanced valuing of each day	Reordered priorities; savoring
New possibilities	New paths, interests, activities	Career change; advocacy; new hobbies
Deeper relationships	Closer connections with others	Increased empathy; reaching out
Increased personal strength	Recognition of one’s resilience	“If I survived this, I can survive anything”
Spiritual/existential growth	Deepened meaning, faith, or philosophical perspective	Greater understanding of suffering, purpose

PTG and PTSD can coexist; growth does not mean absence of distress.

References

1. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.). Arlington, VA: APA.
2. Bisson, J. I., et al. (2021). Psychological therapies for chronic post-traumatic stress disorder. Lancet Psychiatry, 8(2), 181-191.
3. Foa, E. B., et al. (2019). Prolonged Exposure Therapy for PTSD. Oxford University Press.
4. Resick, P. A., et al. (2017). Cognitive Processing Therapy for PTSD. Guilford Press.
5. Shapiro, F. (2018). Eye Movement Desensitization and Reprocessing (EMDR) Therapy (3rd ed.). Guilford Press.
6. Yehuda, R., et al. (2015). Post-traumatic stress disorder. Nature Reviews Disease Primers, 1, 15057.
7. National Institute of Mental Health. (2023). Post-Traumatic Stress Disorder. NIMH.
8. Tedeschi, R. G., & Calhoun, L. G. (2004). Posttraumatic growth. Psychological Inquiry, 15(1), 1-18.