Post-traumatic stress Disorder (PTSD)
Post-Traumatic Stress Disorder (PTSD) is a DSM-5-TR Trauma- and Stressor-Related Disorder characterized by intrusive memories, avoidance, negative alterations in cognition and mood, and altered arousal and reactivity, persisting more than one month after exposure to actual or threatened death, serious injury, or sexual violence.
Overview
Post-Traumatic Stress Disorder (PTSD; DSM-5-TR 309.81) is a Trauma- and Stressor-Related Disorder that develops in some individuals following exposure to actual or threatened death, serious injury, or sexual violence. The diagnosis requires exposure to a Criterion A traumatic stressor and the presence of characteristic symptom clusters across four domains — intrusion, avoidance, negative alterations in cognition and mood, and alterations in arousal and reactivity — persisting more than one month and causing significant distress or functional impairment.
Lifetime PTSD prevalence in the U.S. and Canadian general populations is approximately 6-9%, with substantially higher rates in trauma-exposed populations. Approximately 70% of adults will experience a Criterion A trauma in their lifetime; of these, approximately 8-10% develop PTSD. Rates are higher in women than men (10-12% vs 5-6% lifetime), reflecting greater exposure to interpersonal trauma. Among military veterans, refugees, and survivors of intimate partner violence and sexual assault, rates of PTSD are substantially elevated (20-50% in some samples).
The DSM-5-TR distinguishes PTSD from related conditions including Acute Stress Disorder (308.3, when symptoms are present for 3 days to 1 month after exposure), Adjustment Disorder (309.x, when the stressor does not meet Criterion A or symptoms do not meet PTSD criteria), and Other Specified Trauma- and Stressor-Related Disorder (309.89). The ICD-11 includes a separate diagnosis of Complex PTSD (6B41) for presentations involving prolonged or repeated trauma with additional disturbances of self-organization (severe affect dysregulation, persistent negative self-concept, persistent interpersonal difficulties).
PTSD is highly comorbid. Approximately 80-90% of individuals with PTSD have at least one other psychiatric diagnosis — most commonly depression, anxiety disorders, substance use disorders, and personality disorders. Suicide risk is substantially elevated. Physical health consequences are also significant, including elevated rates of cardiovascular disease, autoimmune conditions, chronic pain, and metabolic syndrome.
PTSD is highly treatable. Multiple evidence-based psychotherapies — Cognitive Processing Therapy, Prolonged Exposure, Eye Movement Desensitization and Reprocessing, and others — produce substantial symptom reduction and recovery in most individuals who complete treatment. Recovery is possible regardless of how long ago the trauma occurred or how severe symptoms have been.
Signs and symptoms
- Intrusive memories or flashbacks — Recurrent, involuntary, distressing memories of the traumatic event(s); flashbacks in which the individual feels or acts as if the trauma were recurring.
- Distressing dreams — Recurrent distressing dreams in which the content or affect is related to the traumatic event(s).
- Psychological or physiological reactivity to cues — Intense or prolonged psychological distress and marked physiological reactions at exposure to internal or external cues that symbolize or resemble an aspect of the trauma.
- Avoidance of trauma-related stimuli — Persistent effortful avoidance of distressing trauma-related thoughts, feelings, or external reminders (people, places, conversations, activities, objects, situations).
- Negative beliefs about self, others, or the world — Persistent and exaggerated negative beliefs ("I am bad," "no one can be trusted," "the world is completely dangerous") that emerge or worsen after the trauma.
- Distorted blame — Persistent, distorted cognitions about the cause or consequences of the trauma that lead the individual to blame themselves or others.
- Persistent negative emotional state — Sustained fear, horror, anger, guilt, or shame; inability to experience positive emotions; markedly diminished interest or participation in significant activities.
- Detachment or estrangement from others — Feelings of being permanently changed or fundamentally different from others; relational withdrawal even from previously close relationships.
- Hyperarousal and hypervigilance — Irritable behaviour or angry outbursts, reckless or self-destructive behaviour, hypervigilance, exaggerated startle response, problems with concentration, sleep disturbance.
- Dissociative symptoms — Depersonalization (feeling detached from self) or derealization (feeling the world is unreal); when prominent, qualifies for the dissociative subtype specifier.
Diagnostic context
The DSM-5-TR criteria for Post-Traumatic Stress Disorder (309.81) require the following:
Criterion A — Stressor exposure: exposure to actual or threatened death, serious injury, or sexual violence in one or more of: directly experiencing the event(s); witnessing the event(s) in person as it occurred to others; learning that the event(s) occurred to a close family member or close friend (in cases of actual or threatened death, the event must have been violent or accidental); experiencing repeated or extreme exposure to aversive details of the traumatic event(s) (e.g., first responders, professionals).
Criterion B — Intrusion symptoms (1+ required): intrusive distressing memories; distressing dreams; dissociative reactions/flashbacks; intense or prolonged psychological distress at exposure to cues; marked physiological reactions to cues.
Criterion C — Avoidance (1+ required): avoidance of distressing trauma-related thoughts/feelings; avoidance of external trauma-related reminders.
Criterion D — Negative alterations in cognitions and mood (2+ required): inability to remember important aspects of the trauma; persistent exaggerated negative beliefs; persistent distorted blame; persistent negative emotional state; markedly diminished interest in significant activities; feelings of detachment from others; persistent inability to experience positive emotions.
Criterion E — Alterations in arousal and reactivity (2+ required): irritable behaviour or angry outbursts; reckless or self-destructive behaviour; hypervigilance; exaggerated startle; problems with concentration; sleep disturbance.
Criterion F — Duration: more than 1 month.
Criterion G — Functional significance: clinically significant distress or impairment.
Criterion H: not attributable to substance use or another medical condition.
Specifiers: with dissociative symptoms (depersonalization or derealization), with delayed expression (full criteria not met until at least 6 months after the event). Differential diagnosis includes Acute Stress Disorder, Adjustment Disorder, anxiety disorders, depressive disorders, dissociative disorders, conversion disorder, psychotic disorders, and traumatic brain injury. Validated assessment instruments include the Clinician-Administered PTSD Scale (CAPS-5; gold standard), PTSD Checklist for DSM-5 (PCL-5), and structured clinical interview.
Causes and risk factors
PTSD development depends on the trauma exposure, individual vulnerability, and post-trauma factors:
Trauma characteristics: severity, duration, proximity, and interpersonal nature of the trauma all matter. Interpersonal traumas (assault, abuse, combat) generally produce higher PTSD rates than impersonal traumas (natural disasters, accidents). Sexual assault and torture have among the highest conditional probabilities of producing PTSD (35-50%+).
Individual pre-trauma factors: female sex, prior psychiatric history, prior trauma exposure (especially in childhood), genetic factors (heritability ~30-40%), neuroticism, low socioeconomic status, lower education, and certain genetic polymorphisms (e.g., FKBP5, COMT, SLC6A4) all elevate risk.
Peritraumatic factors: dissociation during the trauma, perceived life threat, intense fear/helplessness/horror, and lack of social support immediately after are associated with elevated PTSD risk.
Post-trauma factors: ongoing life stress, lack of social support, additional traumatic events, secondary adversities (financial, legal, medical), and cultural/structural barriers to help-seeking all influence trajectory.
Neurobiological factors: PTSD is associated with hyperreactive amygdala, hypoactive ventromedial prefrontal cortex, reduced hippocampal volume, dysregulated HPA axis (typically blunted cortisol response), elevated noradrenergic activity, and altered fear-extinction learning.
Comorbidity: approximately 80-90% of individuals with PTSD have at least one comorbid condition. Most common: major depressive disorder (~50%), substance use disorders (30-50%), other anxiety disorders, traumatic brain injury (in military and accident populations), and chronic pain. Suicide risk is substantially elevated.
Typical treatments
Multiple evidence-based psychotherapies are first-line for PTSD. International guidelines (ISTSS, NICE, APA, VA/DoD) consistently recommend:
Cognitive Processing Therapy (CPT): 12-session structured CBT focused on identifying and modifying “stuck points” — beliefs that prevent recovery (e.g., “it was my fault,” “the world is completely dangerous”). Strong evidence base across trauma types.
Prolonged Exposure (PE): 8-15 session structured protocol involving repeated imaginal exposure to the trauma memory and in vivo exposure to avoided situations. Strong evidence base; one of the most extensively studied PTSD treatments.
Eye Movement Desensitization and Reprocessing (EMDR): trauma-processing modality using bilateral stimulation. Strong evidence base; recommended by WHO, APA, and other major guideline bodies as first-line PTSD treatment.
Trauma-Focused Cognitive behavioural Therapy (TF-CBT): developed for children and adolescents who have experienced trauma. Strong evidence base; involves caregiver participation.
Narrative Exposure Therapy (NET): developed for survivors of multiple traumatic events (refugees, war survivors). Growing evidence base.
Phase-oriented treatment for complex trauma: three-phase approach (stabilization, processing, integration) recommended by ISTSS for individuals with complex PTSD or substantial dissociative features.
Sensorimotor Psychotherapy and Somatic Experiencing: body-oriented approaches that target trauma-related dysregulation through interoceptive awareness and structured movement. Growing evidence base.
Pharmacotherapy: SSRIs paroxetine and sertraline are FDA- and Health Canada-approved for PTSD. Other agents with evidence include venlafaxine (SNRI), prazosin (for trauma-related nightmares), and topiramate. Benzodiazepines are generally avoided due to evidence of poorer long-term outcomes. MDMA-assisted therapy is in late-stage clinical trials and may receive regulatory approval in coming years.
Stellate ganglion block and other emerging interventions are being studied with promising preliminary results in some military and first-responder populations.
Treatment of comorbidity — substance use, depression, traumatic brain injury, chronic pain — is essential for sustained recovery. Integrated dual-diagnosis approaches are appropriate when substance use disorder is co-occurring.
When to seek help
If you are in immediate danger now, contact emergency services: dial 911.
If you are experiencing PTSD symptoms following a trauma, free 24-hour Canadian crisis resources include:
- 9-8-8 — Suicide Crisis Helpline (call or text). Free, 24/7, available across Canada.
- 1-833-456-4566 — Talk Suicide Canada (call); text 45645, 4 PM–midnight ET.
- 1-866-863-0511 — Assaulted Women’s Helpline (Ontario; multilingual; 24/7).
- 1-800-668-6868 — Kids Help Phone (under 20; call or text CONNECT to 686868; 24/7).
- 1-855-242-3310 — Hope for Wellness Helpline (Indigenous-led; counselling in English, French, Cree, Ojibway, and Inuktitut; 24/7).
- 1-800-883-6094 — Veterans Affairs Canada Assistance Service (24/7; for veterans, RCMP, and their families).
- 211 — connects to local social services across Canada.
- 811 — Health Link (Alberta and most provinces) for non-emergency mental-health support.
Professional evaluation is indicated when:
- You have experienced a traumatic event (recently or historically) and are noticing persistent intrusive memories, avoidance, negative changes in mood or thinking, or hyperarousal.
- Symptoms have persisted more than one month after the event and are interfering with relationships, work, or daily life.
- You are using alcohol, drugs, or other strategies to manage symptoms.
- You are experiencing depression, suicidal thoughts, or self-harm urges.
- You are an adult with childhood trauma history that has begun to surface.
- You are a first responder, military member, healthcare worker, or other occupational-trauma-exposed professional and are noticing accumulating impact.
Frequently asked questions
How is PTSD different from a normal stress reaction?
Can PTSD develop years after the trauma?
Is it too late to treat PTSD if the trauma was years ago?
Will I have to talk about all the details of the trauma?
Can I do PTSD treatment without medication?
What is Complex PTSD?
References
- American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.). APA.
- World Health Organization. (2022). International Classification of Diseases, Eleventh Revision (ICD-11). 6B40 PTSD; 6B41 Complex PTSD.
- International Society for Traumatic Stress Studies. (2018). Posttraumatic Stress Disorder Prevention and Treatment Guidelines.
- Bisson, J. I., et al. (2013). Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. Cochrane Database of Systematic Reviews, 12, CD003388.
- van der Kolk, B. (2014). The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Viking.
- Foa, E. B., Hembree, E. A., Rothbaum, B. O., & Rauch, S. (2019). Prolonged Exposure Therapy for PTSD: Emotional Processing of Traumatic Experiences (2nd ed.). Oxford University Press.
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ShiftGrit Psychology & Counselling is professionally regulated, certified, and recognized by leading psychology and mental-health organizations across Alberta and Canada. These associations reflect our commitment to ethical practice, clinical standards, and evidence-informed therapy through Identity-Level Therapy and Reconditioning.
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