This chapter draws on DSM-5-TR (APA, 2022); the 2023 VA/DoD Clinical Practice Guideline for the Management of PTSD and Acute Stress Disorder; the 2018 American Psychological Association Clinical Practice Guideline for PTSD; the 2018 NICE guideline NG116; the 2020 ISTSS Prevention and Treatment Guidelines; recent Cochrane reviews on psychological and pharmacological treatments; landmark RCTs catalogued in the National Center for PTSD evidence syntheses; and current editions of Stahl's Essential Psychopharmacology and Kaplan & Sadock's Synopsis of Psychiatry. Search terms combined "posttraumatic stress disorder" with "epidemiology," "neurobiology," "prolonged exposure," "cognitive processing therapy," "EMDR," "SSRI," "prazosin," "MDMA-assisted," and "comorbidity." Date of last search: 2026-05-09.

Lifetime prevalence of PTSD in U.S. adults is approximately 6-9%, with 12-month prevalence around 3-4%, based on data from the National Comorbidity Survey Replication and the National Epidemiologic Survey on Alcohol and Related Conditions-III.^3-4 Women carry roughly twice the lifetime risk of men (about 10% versus 4%), driven largely by higher rates of sexual assault and interpersonal violence rather than greater biological vulnerability per se.³ Prevalence varies sharply by population: roughly 10-30% of combat-exposed veterans, 30-50% of refugees from active conflict zones, and up to 50% of women following rape develop PTSD.^2,5

Median age of onset is in the early to mid-twenties, mirroring the age distribution of trauma exposure. Children and adolescents develop PTSD as well; DSM-5-TR includes a developmentally specific subtype for children six years and younger.¹ Comorbidity is the rule. In the NCS-R, more than 80% of adults with lifetime PTSD met criteria for at least one other lifetime disorder, most commonly major depressive disorder (about 50%), alcohol use disorder (about 30-50% in men), generalized anxiety disorder, and panic disorder.³ Suicide attempts are 2-3 times more common in PTSD than in the general population, with risk concentrated in those with comorbid depression and substance use.⁶

Risk factors stratify into pretraumatic, peritraumatic, and posttraumatic. Pretraumatic risks include female sex, prior trauma exposure, childhood adversity, lower educational attainment, prior psychiatric illness, and family history. Peritraumatic risks include trauma severity, perceived life threat, interpersonal (versus impersonal) trauma, and dissociation during the event. Posttraumatic risks — the most modifiable category — include lack of social support, ongoing life stressors, and subsequent trauma exposure.² Genetics contributes meaningfully but not deterministically: twin studies estimate heritability of PTSD risk after exposure at roughly 30-40%.⁷

PTSD is best understood as a disorder of failed extinction and altered fear-memory consolidation rather than a generic stress response. The dominant neurocircuit model implicates a hyperresponsive Amygdala, a hypoactive ventromedial prefrontal cortex, and a hippocampus with reduced volume and impaired contextual processing.^8-9 In healthy fear extinction, the ventromedial prefrontal cortex inhibits amygdala output once a previously dangerous cue is shown to be safe; in PTSD, this top-down brake is weak, and the hippocampus fails to bind fear memories to the original context, so a generalized cue (a backfiring car, a particular cologne) reactivates the original fear circuit as if the trauma were recurring.

Neurochemically, several systems are implicated. Noradrenergic tone is elevated, with increased CSF norepinephrine and exaggerated startle, providing the rationale for alpha-1 antagonism with prazosin for trauma-related nightmares.¹⁰ The hypothalamic-pituitary-adrenal axis shows a paradoxical pattern in chronic PTSD — low or normal basal cortisol with enhanced negative feedback sensitivity — distinguishing it from major depression, where cortisol is typically elevated.⁸ Glutamatergic abnormalities, particularly NMDA receptor function, underlie ongoing interest in d-cycloserine augmentation of exposure therapy and in ketamine for acute symptom relief.¹¹ Endocannabinoid and GABAergic systems contribute to arousal regulation and sleep disturbance.

Genetics and epigenetics matter. Twin studies place heritability at roughly 30-40%, with substantial overlap with the heritability of major depression and other internalizing disorders.⁷ FKBP5 polymorphisms interact with childhood maltreatment to elevate adult PTSD risk in several independent samples, an oft-cited example of gene-environment interaction in psychiatry.¹² Genome-wide association studies through the Psychiatric Genomics Consortium have begun to identify genome-wide significant loci, though effect sizes remain small and clinical utility is limited.

Integrative models combine these threads. The traumatic event triggers a fear-conditioning episode that, in the vulnerable brain, fails to extinguish over weeks. Repeated re-experiencing reconsolidates the fear memory in a strengthened form. Avoidance prevents corrective learning. Hyperarousal maintains the system in a state of threat surveillance. Each of the evidence-based treatments — trauma-focused psychotherapies, SSRIs, prazosin — targets one or more of these nodes.

DSM-5-TR Criterion A requires exposure to actual or threatened death, serious injury, or sexual violence by one of four routes: direct experience, witnessing in person, learning that the event occurred to a close family member or friend (with the qualifier that the event was violent or accidental), or repeated or extreme indirect exposure to aversive details (the first-responder and forensic-investigator route).¹ Watching media coverage of a disaster does not satisfy Criterion A unless it is part of work duties.

The remaining criteria require, for at least one month, symptoms across four clusters. Criterion B (intrusion) demands at least one of: recurrent intrusive memories, distressing dreams about the event, dissociative reactions or Flashbacks, intense psychological distress at exposure to trauma cues, or marked physiological reactivity to those cues. Criterion C (avoidance) requires at least one of two: avoidance of internal reminders (memories, thoughts, feelings) or external reminders (people, places, situations). Criterion D (negative alterations in cognitions and mood) requires at least two of seven, including dissociative amnesia for the event, persistent negative beliefs about self or world, distorted blame, persistent negative emotional states, anhedonia, detachment, and inability to experience positive emotions. Criterion E (alterations in arousal and reactivity) requires at least two of six: irritability or aggression, reckless behavior, hypervigilance, exaggerated startle, concentration problems, or sleep disturbance.¹

Criteria F (duration > 1 month), G (clinically significant distress or impairment), and H (not attributable to substance or medical condition) follow the standard structure. Two specifiers carry clinical weight: with dissociative symptoms (depersonalization or derealization, present in roughly 15-30% of cases) and with delayed expression (full criteria not met until at least six months after the event).¹

For children six years and younger, DSM-5-TR provides developmentally adjusted criteria with a lower symptom threshold and fewer required items in the cognition/mood cluster, recognizing that young children express trauma through behavioral re-enactment, regression, and somatic complaints rather than introspective reports.¹

The prototypical presentation is a patient who comes to clinic months after an index event with fragmented sleep, intrusive imagery they describe as "like a movie I can't turn off," and a constricted life — they no longer drive on highways, no longer attend family gatherings, no longer leave the house after dark. Affect is often blunted but the patient startles when a door slams in the corridor. The exam is full of behavioral tells: the chair positioned to face the door, the back never to the window, the eye contact that flicks repeatedly to the room's exits.

Symptom course matters. About half of acute responses to trauma resolve within three months without intervention; persistent PTSD beyond a year is far more likely to chronify.² Symptoms typically wax and wane in response to anniversaries, current life stressors, and re-exposure. Sleep disturbance — initial insomnia, frequent awakenings, and trauma-themed nightmares — is nearly universal and a frequent presenting complaint, sometimes years before the underlying trauma history surfaces.

Atypical presentations include the dissociative subtype (depersonalization, derealization, sometimes dissociative fugue), the somatic-predominant presentation (chronic pain, gastrointestinal symptoms, fatigue) common in primary care, and the externalizing presentation (irritability, aggression, reckless driving, substance use) more common in young men. The delayed-expression specifier captures patients — often veterans returning to civilian life or women whose children reach the age the patient was at the time of childhood abuse — whose symptoms emerge months to years after the index trauma.

Red flags during the interview include a history of repeated or prolonged interpersonal trauma (raises suspicion for the dissociative subtype and ICD-11 CPTSD-equivalent presentations), traumatic brain injury with overlapping symptoms (postconcussive syndrome and PTSD share insomnia, irritability, and concentration problems), and active suicidality. A patient who can describe the trauma in vivid detail without distress may be dissociating; a patient who cannot describe it at all may have dissociative amnesia, also a Criterion D feature.

Acute stress disorder shares the symptom architecture but is diagnosed within the first month after trauma; symptoms persisting beyond one month are reclassified as PTSD if criteria are met.¹ Adjustment disorders apply when the stressor does not meet Criterion A or when the symptom profile does not fit PTSD's four-cluster structure. Major depressive disorder shares anhedonia, sleep disturbance, concentration problems, and negative cognitions — the distinguishing features are intrusion, avoidance of trauma reminders, and physiological reactivity to cues. Roughly half of patients carry both diagnoses; both should be named when both are present.³

Panic disorder shares hyperarousal and physiological reactivity but lacks the trauma-cued specificity and the intrusion cluster. Generalized anxiety disorder shares hypervigilance and sleep disturbance but features pervasive worry across domains rather than trauma-cued reactivity. Obsessive-compulsive disorder can include intrusive thoughts about trauma, but those thoughts are ego-dystonic and ritualized rather than re-experiential. Specific phobia is narrower in scope and lacks the negative-cognition and arousal clusters.

Psychotic disorders enter the differential when flashbacks present as full perceptual experiences. The distinction rests on context: PTSD flashbacks are trauma-themed, cue-triggered, and the patient retains insight that they are reliving rather than perceiving. Borderline personality disorder shares affective instability, dissociation, and self-destructive behavior, and frequently coexists with PTSD given the high rate of childhood trauma in BPD; the distinguishing features are PTSD's discrete index trauma and trauma-cued symptom triggering versus BPD's pervasive instability of identity and interpersonal relationships across contexts.

Medical and substance-induced mimics demand a workup. Hyperthyroidism produces hyperarousal, insomnia, and irritability. Pheochromocytoma produces episodic catecholaminergic surges that can mimic flashbacks. Temporal lobe epilepsy can produce dissociative phenomena, déjà vu, and fear auras. Traumatic brain injury and postconcussive syndrome overlap heavily with PTSD; in combat veterans and assault survivors, both diagnoses commonly coexist.¹³ Stimulant intoxication, alcohol withdrawal, and benzodiazepine withdrawal can each produce hyperarousal and sleep disturbance. Cannabis withdrawal, increasingly common, can mimic the irritability and sleep components.

The trauma interview deserves more deliberation than most other psychiatric interviews. Ask about trauma exposure in every patient presenting with mood, anxiety, sleep, or substance complaints — not because every such patient has PTSD, but because the diagnosis is missed when the question is not asked. Frame the inquiry: "Many people experience events that are upsetting in a lasting way — combat, accidents, assaults, abuse in childhood, the sudden death of someone close. Have you experienced anything like that?" Avoid pressing for graphic detail in the first encounter; establishing the existence and approximate timing of trauma is enough to confirm Criterion A.

Mandatory history elements include a trauma timeline (developmental, military, occupational, interpersonal), a symptom timeline by cluster, a sleep and nightmare history, a substance use history (alcohol and cannabis especially), a suicide and self-harm history, a TBI screen for combat veterans and assault survivors, and a corroborative collateral history when feasible. Ask specifically about military sexual trauma in veterans regardless of gender; reporting rates are low and the question is rarely volunteered.¹⁴

Validated rating scales structure assessment. The Clinician-Administered PTSD Scale (CAPS-5) is the gold-standard structured interview for diagnosis and severity, used in most clinical trials.¹⁵ The PTSD Checklist for DSM-5 (PCL-5) is a 20-item self-report screen with a provisional diagnostic cutoff of 31-33; it is the workhorse instrument for primary care and routine outcome monitoring.¹⁶ The Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) is a 5-item screen used in VA and primary care settings, with positive screens prompting full evaluation. Comorbidity screens (PHQ-9, GAD-7, AUDIT, suicide risk assessment) should accompany every PTSD evaluation.

Physical examination and labs serve to rule out medical mimics and establish baseline function for treatment. A focused exam with vitals (resting tachycardia, hypertension), neurologic screen (TBI sequelae), and thyroid exam is reasonable. Baseline labs typically include CBC, comprehensive metabolic panel, TSH, urine drug screen, and pregnancy test in women of reproductive age. Imaging is not routinely indicated; obtain MRI when seizure, mass, or focal neurologic findings are suspected. Polysomnography is reserved for cases where obstructive sleep apnea is suspected to be driving the sleep complaint, which is common in veterans with combat exposure and weight gain.¹⁷

Two pillars carry the strongest evidence: trauma-focused psychotherapy and SSRIs/SNRIs. Major guidelines diverge on which to recommend first. The 2023 VA/DoD guideline and the 2018 APA guideline give a strong recommendation for trauma-focused psychotherapy over pharmacotherapy when both are accessible, on the basis of larger and more durable effect sizes; pharmacotherapy is recommended when psychotherapy is unavailable, refused, or insufficient.^18-19 NICE NG116 takes a similar position, recommending trauma-focused CBT or EMDR as first-line and reserving SSRIs/venlafaxine for patients who decline psychotherapy or have not responded.²⁰ In practice, combination treatment is common, particularly in patients with significant comorbid depression.

Pharmacotherapy

Sertraline (Zoloft) and paroxetine (Paxil) are the only agents with FDA approval for PTSD, both based on placebo-controlled RCTs in mixed-trauma populations.^21-22 Strong evidence supports SSRIs as the first-line drug class. Venlafaxine extended-release (Effexor XR) has comparable efficacy in head-to-head trials and is recommended at the same tier by the VA/DoD and NICE guidelines despite its off-label status for this indication.^18,20,23 Typical target doses are sertraline 50-200 mg/day, paroxetine 20-60 mg/day, and venlafaxine XR 75-300 mg/day, with response often requiring 8-12 weeks at therapeutic dose.

Fluoxetine has supportive but more modest evidence. Mirtazapine has small RCT support and is often chosen when sleep disturbance and weight loss dominate the picture, though evidence quality is limited. Tricyclic antidepressants (amitriptyline, imipramine) and the MAOI phenelzine have older positive RCTs but are rarely used first-line given tolerability and overdose-toxicity concerns.²⁴

Prazosin, an alpha-1 adrenergic antagonist, has historical support for trauma-related nightmares and sleep disturbance. The picture became more complex after the 2018 PACT trial, a multisite VA RCT, found no benefit over placebo for combat-related PTSD nightmares in chronic, stable veterans.²⁵ Earlier and subsequent meta-analyses still suggest benefit in selected populations, particularly those with prominent autonomic features and active nightmares; major guidelines have downgraded prazosin from a strong to a conditional recommendation.^18,26 Typical dosing starts at 1 mg at bedtime and titrates to 5-15 mg at bedtime as tolerated, watching for orthostatic hypotension.

Several agents are commonly used but poorly supported. Benzodiazepines have no demonstrated efficacy for PTSD, may interfere with extinction learning during exposure-based therapy, and carry meaningful risks of dependence and impaired arousal regulation; major guidelines recommend against their use as monotherapy or first-line.^18,27 Atypical antipsychotics — risperidone in particular — were tested in the VA Cooperative Study #504 as adjuncts in SSRI partial responders and failed to demonstrate efficacy; quetiapine has limited supportive data and is sometimes used adjunctively for sleep, but evidence is low quality and metabolic risks are real.²⁸ Topiramate, lamotrigine, and other anticonvulsants have inconsistent results.

Psychotherapy

Three trauma-focused psychotherapies share strong, consistent evidence and are the recommended first-line treatments by every major guideline: prolonged exposure (PE), cognitive processing therapy (CPT), and eye movement desensitization and reprocessing (EMDR).^18-20 Effect sizes versus waitlist or supportive therapy are large; head-to-head comparisons among the three generally show equivalence, allowing patient preference and therapist availability to drive selection.

Prolonged exposure, developed by Foa and colleagues, combines repeated imaginal exposure to the trauma memory with in vivo exposure to avoided situations and psychoeducation. A typical course is 8-15 weekly 90-minute sessions. The mechanism is straightforward in extinction-learning terms: repeated activation of the fear memory in a safe context allows new safety learning to inhibit the original conditioned response.²⁹ Cognitive processing therapy, developed by Resick, focuses on identifying and modifying "stuck points" — distorted beliefs about the trauma's meaning, particularly around trust, safety, power, esteem, and intimacy — over 12 weekly sessions, with or without a written trauma account.³⁰ EMDR, developed by Shapiro, pairs brief activation of the trauma memory with bilateral stimulation (eye movements, taps, or tones); the mechanism remains debated, but trial-level efficacy is established.³¹

Trauma-focused cognitive behavioral therapy (TF-CBT) for children and adolescents adapts these principles for younger patients with caregiver involvement.³² Brief eclectic psychotherapy and narrative exposure therapy have supportive evidence and are used selectively. Stress inoculation training, present-centered therapy, and supportive counseling are non-trauma-focused alternatives with smaller effect sizes; they are reasonable second-line options for patients who decline trauma-focused work but should not displace it as first-line.

Neuromodulation

Repetitive transcranial magnetic stimulation (rTMS) has growing evidence in PTSD, with stimulation typically targeted to the right or left dorsolateral prefrontal cortex. Several randomized trials and meta-analyses suggest moderate symptom reduction, though optimal protocols, target site, and durability remain areas of active investigation. The FDA has not granted a specific PTSD indication, but rTMS is offered in some specialty centers, particularly for patients with comorbid major depression where it carries an established indication.³³ Stellate ganglion block, a regional anesthetic procedure targeting cervical sympathetic chain, has gained interest with mixed RCT results; recent VA-funded studies have not consistently replicated early positive findings.³⁴

Adjunctive

Sleep is the most reliably reported persistent symptom and a frequent residual after otherwise successful treatment. CBT for insomnia (CBT-I) and imagery rehearsal therapy for nightmares have supportive evidence and are often added to the core treatment.³⁵ Exercise, mindfulness-based stress reduction, and yoga have small-to-moderate effects on PTSD symptoms in meta-analyses and are reasonable adjuncts, particularly given the cardiovascular and metabolic risks accumulated over a chronic course.³⁶ Treating comorbid alcohol use disorder is essential — concurrent treatment of PTSD and AUD using exposure-based protocols (the COPE protocol, for example) shows benefit comparable to sequential treatment without worsening substance use.³⁷

Adverse effects of trauma-focused psychotherapy are real but generally limited and transient. Patients commonly report symptom worsening in the first 1-3 sessions of exposure-based work as fear memories are reactivated; dropout rates of 20-30% are reported across PE and CPT trials, with comparable figures for EMDR.^29-31 Therapist availability is the major real-world limitation: the supply of clinicians trained in evidence-based trauma protocols falls short of need in most health systems, and adoption rates within the VA and elsewhere have been documented as suboptimal.

Pharmacotherapy harms cluster by class. SSRIs and SNRIs carry the familiar profile: gastrointestinal upset, sexual dysfunction (often persistent and underdiscussed), sleep changes, hyponatremia (particularly in older adults), and discontinuation syndrome with abrupt cessation. Paroxetine adds anticholinergic burden and is the SSRI most associated with weight gain and discontinuation symptoms; it is associated with increased risk of cardiovascular malformations when used in the first trimester of pregnancy and is generally avoided.³⁸ Venlafaxine produces dose-dependent diastolic hypertension at higher doses and prominent discontinuation symptoms.

Prazosin's harms — orthostatic hypotension, syncope, priapism — require careful titration and patient counseling, particularly in older adults and those on other antihypertensives. Atypical antipsychotics, when used adjunctively, expose patients to metabolic syndrome, extrapyramidal effects, and sedation for limited symptomatic gain. Benzodiazepines pose dependence, withdrawal, falls, motor vehicle accident risk, and overdose risk in combination with opioids or alcohol — a particular concern in PTSD given the high rate of comorbid substance use.²⁷

Limitations of the evidence base deserve explicit acknowledgment. Most pharmacotherapy trials enrolled mixed-trauma populations with short follow-up (12 weeks is typical), limiting inference about long-term efficacy and combat-specific or sexual-assault-specific outcomes. Veteran populations show smaller effect sizes than civilian populations across most modalities, for reasons that include chronicity, comorbid TBI, and secondary gain from disability evaluation. Pediatric and adolescent evidence is thinner; geriatric evidence is sparser still. Network meta-analyses can rank interventions but rest on heterogeneous samples and varied control conditions.³⁹

Children and adolescents respond well to TF-CBT and to developmentally adapted CPT and PE. SSRIs in pediatric PTSD have weaker evidence than in adults and carry the FDA black box warning for suicidal ideation in patients under 25; sertraline trials in pediatric PTSD have been largely negative as monotherapy.^32,40 Psychotherapy is the strong first-line.

Older adults present challenges of comorbid medical illness, polypharmacy, and a higher burden of trauma exposure across the lifespan that may resurface with retirement, bereavement, or cognitive decline. SSRIs are tolerated but require lower starting doses and attention to hyponatremia, falls, and drug interactions. Trauma-focused therapy is feasible and effective in this population but is underutilized.⁴¹

Perinatal PTSD — both pregnancy-related (after pregnancy loss, traumatic birth, NICU experience) and pre-existing — requires careful risk-benefit balancing. Sertraline has the most reproductive-safety data of the SSRIs and is generally preferred. Paroxetine is generally avoided in the first trimester. Trauma-focused psychotherapy is preferred when feasible, particularly during the first trimester.⁴²

Comorbid traumatic brain injury is common in combat veterans and survivors of motor vehicle accidents and assault. Symptom overlap (insomnia, irritability, concentration problems, headaches) complicates diagnosis. Both diagnoses can be treated concurrently; trauma-focused therapy outcomes are slightly attenuated but still meaningful in mild-to-moderate TBI. Severe TBI with substantial cognitive impairment may require modified approaches.¹³

Comorbid alcohol and substance use disorder is the rule rather than the exception. Concurrent treatment with integrated protocols (Concurrent Treatment of PTSD and Substance Use Disorder Using Prolonged Exposure, COPE; Seeking Safety) is supported by RCTs and is now the standard recommendation; the older sequential model — "abstinence first, trauma later" — is no longer favored.^37,43

Cultural considerations shape both presentation and engagement. Refugees and forced migrants present with high prevalence and often with complex polytrauma. Somatic and idiom-of-distress presentations are common in many non-Western populations. Use of professional interpreters, attention to acculturation status, and adaptation of trauma narratives to cultural meaning are essential. The Cultural Formulation Interview in DSM-5-TR provides a structured aid.^1,5

Natural history is heterogeneous. Roughly half of acute posttraumatic responses remit within three months without formal treatment, particularly when social support is intact and ongoing stressors are limited. Symptoms persisting beyond a year tend to chronify; without treatment, a substantial minority — perhaps a third in community samples — remains symptomatic at a decade.^2-3 Response and remission with evidence-based treatment are meaningful but not uniform: across trauma-focused psychotherapy trials, roughly 40-60% of completers achieve loss of diagnosis at end-of-treatment, with smaller proportions achieving full remission of symptoms.^18,29-31 SSRIs produce response rates around 50-60% and remission in 20-30%; combination treatment offers modest incremental benefit in selected populations.

Suicide risk persists across the course. PTSD is associated with a 2-3 fold increase in suicide attempts and elevated rates of completed suicide, with risk concentrated in those with comorbid depression and alcohol use disorder.⁶ Functional outcomes — work, relationships, physical health — track symptom severity. Cardiovascular morbidity and mortality are elevated, attributable in part to chronic autonomic activation, smoking, and reduced physical activity; this is one reason why exercise and cardiovascular risk-factor management are reasonable adjuncts.⁴⁴

Predictors of poor outcome include early age at index trauma, prolonged or repeated trauma, dissociative symptoms, comorbid depression and substance use, ongoing legal or compensation processes, and limited social support. Predictors of better outcome include shorter duration of illness, single discrete trauma, intact pretrauma functioning, and engagement with evidence-based treatment.

Most PTSD care is outpatient. Inpatient hospitalization is reserved for acute suicide or homicide risk, severe self-neglect, or comorbid conditions (severe depression, substance withdrawal, psychosis) requiring stabilization. Voluntary brief admission is sometimes useful for medication initiation in patients with prior tolerability problems or for crisis stabilization during a high-risk period.

Suicide risk assessment in PTSD requires attention to specific risk markers: prior attempts, command hallucinations or vivid trauma re-experiencing with command-like content, acute substance intoxication, recent loss of social support, access to firearms (a particularly pressing concern in veteran populations and rural communities), and the constellation of insomnia, agitation, and hopelessness. Means restriction counseling — especially around firearms — is among the highest-yield interventions and should be discussed openly.⁴⁵

Acute agitation in the PTSD patient — typically triggered in emergency departments, hospital wards, or detention settings — responds to verbal de-escalation, sensory accommodation (lighting, exit visibility, posture), and short-acting agents when needed. Avoid restraint if at all possible; physical restraint and forced medication can re-traumatize and complicate the therapeutic relationship for years afterward.

Acute traumatic exposures present a separate question: should an asymptomatic survivor receive prophylactic intervention? Single-session psychological debriefing has been studied extensively and is not recommended; some trials suggest it may worsen outcomes, possibly by interfering with normal recovery processes.⁴⁶ Watchful waiting with screening at 4-6 weeks, brief skills-based interventions, and timely access to evidence-based care if symptoms persist beyond a month is the current standard. Pharmacological prophylaxis with hydrocortisone or propranolol has limited and inconsistent supportive evidence.⁴⁷

Complex PTSD is recognized in ICD-11 as a separate diagnosis but not in DSM-5-TR. Proponents argue that the additional disturbances in self-organization following prolonged or repeated trauma require distinct treatment approaches; critics note overlap with borderline personality disorder, the dissociative subtype of PTSD, and chronic depression. The clinical reality is that patients meeting ICD-11 CPTSD criteria often have heavier symptom burden, more childhood trauma, and slower treatment response, but evidence that they require fundamentally different interventions remains limited.⁴⁸

MDMA-assisted psychotherapy has accumulated phase 2 and phase 3 RCT evidence with large effect sizes, but the FDA in 2024 declined to approve the application from Lykos Therapeutics, citing concerns about study methodology, blinding, expectancy effects, and adverse-event reporting.⁴⁹ The treatment remains investigational in the United States. The methodological challenges — psychotherapy-augmenting drugs are difficult to blind, and patient-reported outcomes are vulnerable to expectancy effects — apply to ketamine-assisted and psilocybin-assisted approaches as well, all of which are areas of active study.

Ketamine for PTSD has moderate but inconsistent evidence as a short-term symptom-reducing agent, with effects that diminish over weeks. Its role relative to established treatments is unsettled; major guidelines do not yet endorse it as standard care for PTSD specifically, though it is increasingly used in clinical practice for refractory cases, often borrowing protocols from depression treatment.¹¹

Cannabis and cannabinoids — including nabilone for nightmares — are commonly used by patients with PTSD, but RCT evidence is limited and inconsistent. Several jurisdictions have approved medical cannabis for PTSD on the basis of patient demand and limited trial data; major psychiatric guidelines have not endorsed this practice. The evidence base for cannabis worsening, rather than improving, long-term PTSD outcomes is also growing.⁵⁰

Trial-level efficacy of EMDR is established, but mechanistic claims about bilateral stimulation as the active ingredient remain debated. Dismantling studies have not consistently shown that the eye-movement component is necessary; the imaginal exposure and cognitive restructuring shared with PE and CPT may be doing the work. The clinical implication is modest — EMDR works — but the theoretical landscape is unsettled.

• DSM-5-TR moved PTSD out of anxiety disorders into a dedicated chapter on Trauma- and Stressor-Related Disorders.
• Criterion A requires exposure to actual or threatened death, serious injury, or sexual violence; media exposure does not qualify unless work-related.
• The four symptom clusters are intrusion (B), avoidance (C), negative alterations in cognition and mood (D), and alterations in arousal and reactivity (E).
• Symptoms must persist for more than one month for PTSD; less than one month with full criteria is acute stress disorder.
• Lifetime prevalence is approximately 6-9% in U.S. adults, twice as high in women as men.
• Sertraline and paroxetine are the only FDA-approved agents for PTSD; venlafaxine is recommended at the same tier off-label.
• Major guidelines recommend trauma-focused psychotherapy (PE, CPT, EMDR) over pharmacotherapy when both are available.
• Benzodiazepines are not recommended; they may impair extinction learning and worsen long-term outcomes.
• Prazosin's recommendation was downgraded after the negative 2018 PACT trial in chronic combat veterans.
• Single-session psychological debriefing is not recommended after acute trauma and may worsen outcomes.
• The dissociative subtype (depersonalization or derealization) and the with-delayed-expression specifier are the two principal DSM-5-TR specifiers.
• ICD-11 recognizes complex PTSD as a separate diagnosis; DSM-5-TR does not.
• Comorbid alcohol use disorder should be treated concurrently with PTSD, not sequentially.
• The CAPS-5 is the gold-standard structured interview; the PCL-5 is the standard self-report screen.
• Suicide risk in PTSD is elevated 2-3 fold; firearm means restriction counseling is high-yield.

No external funding. No conflicts of interest declared. Drafted with Claude (Anthropic) and human-edited by the Psychpedia editorial team. Peer-review status: pending.