Acute Stress Disorder

Etiology

ASD arises as a maladaptive response to experiencing or witnessing a traumatic event involving actual or threatened death, serious injury, or sexual violence. The development of ASD depends on a complex interplay among the severity of trauma exposure, individual vulnerability factors, and the type of event experienced. According to findings from a population-based survey conducted by Perrin et al involving 3691 adults from an urban community, approximately 21% of individuals reported exposure to at least 1 traumatic event during their lifetime, whereas about 5% met criteria for PTSD.[6]

Although exposure to trauma is common, most individuals recover without long-term complications. A smaller subset develops ASD or later progresses to PTSD. The likelihood of developing these conditions varies based on factors such as trauma type, preexisting psychiatric disorders, personality traits, and coping mechanisms. For example, sexual abuse was identified as the trauma associated with the highest risk of PTSD, followed by prior psychiatric illness and maladaptive coping strategies. Perrin et al findings highlight that although trauma exposure is widespread, only a minority of individuals develop clinically significant stress disorders, underscoring the importance of early recognition and targeted intervention for those at highest risk.[6]

The risk of developing a trauma-related disorder increases with specific factors, including sexual assault, violent crime, or severe physical injury. Preexisting psychiatric conditions such as bipolar disorder, anxiety, or alcohol dependence, as well as certain personality traits such as high neuroticism and maladaptive coping strategies, further increase susceptibility. These risk factors underscore that although trauma exposure is nearly universal, individual biological, psychological, and contextual factors determine who develops clinically significant acute stress reactions.

Epidemiology

Because of its short duration and co-occurrence with normal acute stress reactions and PTSD, epidemiologic research on ASD is difficult to conduct. Consequently, data remain insufficient, especially in the general population. Most research is conducted in selected populations of trauma survivors, with ASD rates varying widely depending on the nature and degree of trauma, sample characteristics, and time of evaluation.[7] For example, trauma caused by assault is associated with higher ASD rates than trauma caused by accidents.[8]

Prevalence rates following severe physical injury have been reported to be 24% at 1 week and 11% to 40% at 1 to 2 weeks after injury.[8] Specific prevalence rates include the following:

• Results from a 2018 meta-analysis found an overall ASD prevalence of 15.8% in individuals involved in road traffic accidents.[9] 
• The estimated prevalence of acute stress disorder among children aged 7 to 17 years presenting to emergency departments was approximately 14% when evaluated 2 weeks after experiencing a traumatic event, underscoring the importance of early recognition and intervention in this population.[8] 
• Higher rates, approximately 15%, have been reported in specific populations, such as mothers of preterm infants, compared with those who delivered at term, indicating increased vulnerability in settings involving perinatal stress and neonatal complications.[10] 

Research specifically examining the risk factors for ASD is limited, and much of what is known has been extrapolated from studies on PTSD because of the close clinical and pathophysiologic overlap between the conditions. However, existing evidence indicates that the development of ASD following trauma exposure is multifactorial and influenced by a combination of pretraumatic, peritraumatic, and posttraumatic variables.[11][12][13]

Pretrauma Factors

Pretrauma factors associated with increased vulnerability include female sex, a history of psychiatric disorders such as anxiety or depression, prior traumatic event exposure, lower socioeconomic status or limited education, personality traits such as high neuroticism, genetic predisposition (although less well defined for ASD specifically), and intellectual disability. Pretrauma vulnerability factors may lower resilience or impair coping mechanisms in the aftermath of trauma.

Peritrauma Factors

Peritrauma factors, which are present during the traumatic event, play a critical role in the acute stress response. Greater trauma severity or intensity demonstrates a dose–response effect, with higher risk seen in cases involving interpersonal or assaultive violence (eg, rape, physical assault) compared with nonassaultive events. Additional contributors include perceived threat to life, the presence of severe physical injury, and a sense of helplessness during the incident.

Posttrauma Factors

Posttrauma factors influencing ASD onset and persistence include peritraumatic dissociation, limited or absent social support following the event, the use of avoidant or maladaptive coping strategies, persistent physical pain, intensive care unit stays, traumatic brain injury, new functional disability, and exposure to subsequent life stressors. Posttraumatic stressors can perpetuate physiological hyperarousal and interfere with recovery processes, thereby increasing the likelihood of developing clinically significant acute stress reactions. Understanding these risk factors is essential for clinicians to identify vulnerable individuals early and implement targeted interventions. Risk factor assessment also provides context for interpreting epidemiologic data, because prevalence rates and outcomes vary significantly across populations and trauma types.[11][12][13]

Pathophysiology

The exact processes by which ASD occurs after trauma exposure and the reasons for recovery versus persistence of chronic symptoms are not well understood. However, current models suggest dysregulation of neural circuits that mediate fear learning, memory, and emotion. Fear conditioning is thought to be the primary mechanism involved in acute stress responses. Fear conditioning is a learning process in which previously neutral cues become fear-provoking after being associated with a traumatic event. Under normal circumstances, these conditioned fear responses diminish while the brain learns that the stimulus is no longer threatening, a process known as fear extinction. In trauma- and stressor-related disorders, impaired fear extinction leads to persistent fear responses and ongoing psychological distress.[14]

Results from neurobiological studies, mainly in PTSD, revealed abnormalities in the amygdala, hippocampus, and medial prefrontal cortex. The basolateral amygdala complex is important for the consolidation and expression of fear memories, and the central nucleus of the amygdala regulates fear output. The hippocampus adds contextual information to fear memories and helps with threat and safety discrimination. The medial prefrontal cortex, particularly the ventromedial prefrontal cortex, sends top-down inhibitory signals to the amygdala, a process essential for the retrieval of fear-extinction memories and for emotional regulation.[14][15] Abnormal connectivity between the ventromedial prefrontal cortex and amygdala is often seen in patients with PTSD and is linked to poor fear extinction.[14]

Functional and structural changes are also reported. Decreased hippocampal volume, specifically in CA3 and the dentate gyrus, is reported in PTSD and may be a risk factor. Results from neuroimaging studies showed amygdala hyperresponsivity to threat stimuli and medial prefrontal cortex hypoactivity during tasks involving fear inhibition or retrieval of extinction memories.[15][16] Results from studies of acute trauma survivors linked early hyperactivation in certain cortical areas (eg, superior prefrontal, cingulate cortex, precuneus) with PTSD.[17]

The molecular basis of circuit dysfunction involves alterations in key neurotransmitter systems within the brain’s fear network. Dysregulation of inhibitory γ-aminobutyric acid–mediated and excitatory glutamatergic signaling disrupts the balance of neural activity, whereas changes in neurotrophic factors, particularly brain-derived neurotrophic factor, affect synaptic plasticity, fear memory formation, and extinction learning. Epigenetic modifications are expected to contribute to the observed heterogeneity in posttraumatic vulnerability and resilience.[14]

History and Physical

The diagnosis of ASD is usually made on the patient’s history and the presence of characteristic symptoms after a traumatic event, according to DSM-5-TR criteria, consistent with the DSM-5 diagnostic framework for trauma- and stressor-related disorders.[3][5]

ASD Diagnostic Features 

1. Trauma exposure:  Exposure involved actual or threatened death, serious injury, or sexual violence in 1 or more of the following ways:

• Direct experience of the traumatic event(s)
• Witnessing the event(s) in person as they occurred to others
• Learning that the traumatic event(s) occurred to a close family member or a close friend. 

Repeated or intense exposure to details of the traumatic event(s) (eg, first responders handling human remains, police officers repeatedly exposed to details of child abuse). Exposure through electronic media (television or the internet) does not apply unless the exposure is work-related.

For children 6 or younger: Direct witnessing only; exposure to electronic media is specifically excluded.

2. Symptoms: At least 9 symptoms from any of the 5 categories listed below, occurring or worsening after the traumatic event(s) and lasting from 3 days to 1 month after the traumatic event:

• Intrusion symptoms: 
  • Involuntary, frequent, and distressing memories that occur automatically and outside the individual’s control of the traumatic event(s).
  • In children older than 6 years, repetitive play may occur in which themes or aspects of the traumatic event(s) are expressed. Recurring nightmares are directly linked to the traumatic event(s) and maintain their connection to the traumatic event(s) in both their content and affect. Children may experience frightening nightmares even though they do not remember their contents. 
  • The individual exhibits dissociative reactions (flashbacks) that cause them to relive the traumatic event(s) as if they were currently experiencing them.
  • The individual experiences either intense psychological distress or marked physiological reactions when exposed to internal or external stimuli that symbolize the traumatic event(s).
• Negative mood: A continuous inability to feel positive emotions, such as happiness, satisfaction, or love.
• Dissociative symptoms: 
  • An altered sense of reality (eg, seeing oneself from another’s perspective, being in a daze, or perceiving slowed time).
  • The patient cannot remember an important aspect of the traumatic event; dissociative amnesia is the cause, rather than another factor such as head injury, alcohol, or drugs.
• Avoidance symptoms: 
  • Efforts to avoid memories, thoughts, and feelings that are connected to or arise from the traumatic event(s).
  • Avoidance of external triggers (people, places, activities, objects, or other cues) that trigger distressing memories, thoughts, or feelings associated with or connected to the traumatic event(s).
• Arousal symptoms:
  • Sleep disturbance (eg, trouble falling or staying asleep)
  • Irritability and angry outbursts (with little or no provocation), typically expressed as verbal or physical aggression toward people or objects
  • Hypervigilance
  • Problems with concentration
  • Excessive startle response

3. Duration: The duration of the disturbance (Criterion B symptoms) is 3 to 30 days after trauma exposure.

4. Functional impact: The disturbance creates clinically significant distress and leads to impairment in social, occupational, or other important areas of life.

5. Exclusions: The disturbance is not the result of substance-related effects or other medical conditions, and it is not better explained by a brief psychotic disorder.

Accurate diagnosis requires careful assessment of trauma exposure, symptom configuration, functional impact, and exclusion of alternative explanations.

Evaluation

Diagnosis relies on clinical judgment based on a full history and mental status examination. Observational data, coupled with empathetic elicitation of the patient’s narrative, are central to the assessment. Patients may initially find it difficult to describe their experiences, and more than 1 assessment may be needed.

Several rapid and validated psychometric instruments are available to help evaluate ASD in children and adults. The Child Stress Disorders Checklist provides a brief assessment of ASD and PTSD symptoms in children.[18] The Acute Stress Disorder Scale is a validated adult self-report measure for ASD symptoms.[19] Structured interviews, including the Acute Stress Disorder Interview, may also assist clinicians in high-volume settings, although the diagnosis remains clinical.

The evaluation of ASD relies primarily on a thorough clinical assessment. ASD is a psychiatric condition, but its presentation may include physiologic manifestations such as tachycardia and measurable neurobiological correlates in fear and stress circuits. No laboratory test, biomarker, or imaging findings confirm ASD; testing should be guided by the need to rule out medical, neurologic, or substance-related mimics.

Key Components of Evaluation

• Clinical interview: Verify the qualifying traumatic event and systematically evaluate intrusion, negative mood, dissociation, avoidance, and arousal symptoms. Determine symptom duration, distress, and functional impairment.
• Differential diagnosis: Exclude alternative explanations such as normal stress reactions, adjustment disorder, panic disorder, brief psychotic disorder, substance-related effects, traumatic brain injury, and other medical conditions.
• Psychometric measures: Validated measures can support symptom assessment and monitoring, but do not replace clinical diagnosis. The Acute Stress Disorder Scale may be used for adult ASD symptoms.[19] The Child Stress Disorders Checklist is available for pediatric populations.[18] PTSD-focused instruments such as the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) or Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) may help identify patients who need more comprehensive trauma-focused assessment during follow-up.
• Safety assessment: Trauma exposure and severe acute stress symptoms warrant assessment of suicidal ideation, intent, plan, prior self-harm, agitation, severe insomnia, substance use, and available supports, especially when depression, anxiety, or later PTSD symptoms are present.[11]

Treatment / Management

Management after trauma is stepped and time-sensitive. In the first hours to days, the priorities are physical safety, urgent medical and psychiatric risk assessment, stabilization, practical support, and connection with family, clinicians, or community resources. Most people exposed to trauma improve without formal psychotherapy, so early care should not pathologize every normal acute reaction. Patients with persistent, impairing ASD symptoms need planned follow-up and, when available, trauma-focused psychotherapy rather than routine medication prophylaxis.[20](A1)

General Measures and Early Support 

Interventions in the immediate posttrauma period should follow these principles: ensure safety and comfort, reduce intense arousal, support connection with family or trusted community resources, provide practical help, offer clear psychoeducation about common stress reactions, and encourage a gradual return to safe routines. Scheduled follow-up is useful because symptoms may change over the first month. Single-session psychological debriefing that requires a detailed trauma narrative should be avoided; Veterans Affairs and Department of Defense (VA/DoD) guidance do not support it as a preventive intervention, and it may worsen outcomes in some patients.[20][National Child Traumatic Stress Network. Psychological First Aid Field Operations Guide][WHO. Guidelines for the Management of Conditions Specifically Related to Stress].(A1)

Psychotherapy for diagnosed ASD

For patients who meet ASD criteria from 3 days to 1 month after trauma and have clinically significant distress or impairment, the 2023 VA/DoD guideline suggests trauma-focused cognitive behavioral psychotherapy to reduce the risk of later PTSD (weak recommendation).[20] The evidence base is most consistent for brief, multisession trauma-focused cognitive behavioral therapy (CBT) that includes psychoeducation, arousal management, cognitive restructuring, imaginal or narrative work, and graded in vivo exposure. The same broad family of trauma-focused treatments is central to established PTSD care, but the evidence for each approach in the acute ASD window is not equally developed.(A1)

• Trauma-focused cognitive behavioral therapy: Trauma-focused CBT is the most supported early intervention for diagnosed ASD. Clinicians trained in trauma-focused CBT should pace exposure and cognitive work safely while monitoring sleep, suicidality, substance use, pain, and other factors that can interfere with treatment engagement.[20] This intervention can be integrated with follow-up care, psychoeducation, and safety planning when symptoms persist or impair functioning.
• Prolonged exposure-based approaches: Prolonged exposure involves repeated, structured contact with trauma memories and avoided but safe reminders. Modified early prolonged exposure protocols are being studied after recent trauma, including rape and physical injury, but recent publications include protocol, feasibility, and qualitative reports rather than completed efficacy trials. These protocols support careful study and selective use within trauma-focused CBT expertise, not a blanket claim that early prolonged exposure prevents PTSD in all patients.[21]
• Cognitive processing therapy: Cognitive processing therapy (CPT) targets maladaptive trauma-related beliefs, including guilt and self-blame. CPT has an established role in PTSD treatment and may be clinically relevant when guilt or distorted responsibility dominates the presentation. However, ASD-specific evidence is more limited.[22]
• Eye movement desensitization and reprocessing: Eye movement desensitization and reprocessing (EMDR) is an established PTSD treatment. For early intervention following recent trauma, results from systematic reviews suggest short-term symptom benefit, but study quality, sample size, and safety reporting remain limitations. EMDR can be considered when delivered by trained clinicians, but it should not replace the better-established trauma-focused CBT recommendation for diagnosed ASD.[23]
(A1)

Pharmacotherapy

No medication has established efficacy for treating ASD or preventing progression from ASD or acute stress reactions to PTSD. The 2023 VA/DoD guideline found insufficient evidence to recommend for or against pharmacotherapy for PTSD prevention in patients with acute stress reaction or ASD. Reviewed agents included propranolol, hydrocortisone, oxytocin, docosahexaenoic acid, gabapentin, paroxetine, and escitalopram; the available studies do not justify routine posttrauma medication prophylaxis.[20](A1)

Medication may still be appropriate for a separate indication or a severe target symptom, such as major depression, psychosis, alcohol or sedative-hypnotic withdrawal, dangerous agitation, or persistent insomnia that prevents recovery. In those situations, the medication treats the comorbid condition or symptom burden, not ASD itself. Antipsychotics should not be used routinely for ASD; VA/DoD guidance also suggests against antipsychotic augmentation for PTSD because benefits are uncertain, and metabolic, neurologic, and cardiac adverse effects can be clinically significant.[20](A1)

• Benzodiazepines: Benzodiazepines should be avoided in ASD and PTSD care. World Health Organization guidance advises against benzodiazepines for acute traumatic stress symptoms or acute posttrauma insomnia in the first month. Additionally, VA/DoD guidance strongly recommends against benzodiazepines for PTSD because of limited benefit, misuse risk, cognitive adverse effects, and possible interference with trauma-focused psychotherapy.[20]
• Cannabis and cannabinoid-based products: Cannabis and cannabinoid products should not be used to treat ASD or PTSD. Evidence does not support routine benefit for core trauma symptoms, and potential harms include worsening anxiety, cognitive impairment, psychosis risk in vulnerable patients, and substance use disorder.[20][24]
• Prazosin may be used off-label for PTSD-related nightmares in selected patients, but it has no established role in ASD prevention or routine ASD treatment. Symptom-targeted medication should therefore be brief, closely monitored, and paired with follow-up, psychoeducation, safety planning, and referral for trauma-focused psychotherapy when ASD symptoms persist.[20]
(A1)

Differential Diagnosis

The differential diagnosis of ASD requires careful review of symptom duration, trauma exposure, dominant symptom pattern, and alternative medical or toxic causes. ASD should be diagnosed only when symptoms follow a qualifying traumatic event, last at least 3 days but less than 1 month, cause clinically significant distress or impairment, and are not better explained by a substance, a medical condition, or another mental disorder. The principal differential diagnoses include:

Normal Acute Stress Reactions

Transient distress, sleep disturbance, heightened startle, or intrusive thoughts are common in the first days after trauma. These reactions do not meet criteria for ASD unless the patient has at least 9 qualifying symptoms, clinically significant impairment or distress, and symptoms persist for 3 days or longer.

PTSD and Complex PTSD

PTSD is considered when trauma-related symptoms persist beyond 1 month. ASD is a risk marker for later PTSD, but it is an imperfect predictor; many patients who later develop PTSD do not meet full ASD criteria during the first month after trauma.[1][4][5][4][8] Complex PTSD is an International Classification of Diseases construct that includes core PTSD symptoms plus persistent disturbances in self-organization, including affect dysregulation, negative self-concept, and interpersonal difficulties. Complex PTSD is not diagnosed during the acute ASD window, but it may become relevant when symptoms persist after prolonged or repeated trauma.

Adjustment Disorder

Adjustment disorder involves emotional or behavioral symptoms in response to an identifiable stressor that may not meet the DSM-5-TR Criterion A trauma threshold. Clinicians should consider adjustment disorder when the symptom profile does not meet full ASD or PTSD criteria.

Panic Disorder

Panic attacks may occur in ASD. Panic disorder is favored when attacks are recurrent and unexpected, followed by persistent concern about future attacks or maladaptive avoidance that is not primarily organized around trauma reminders.

Brief Psychotic Disorder and Primary Psychotic Disorders

Brief psychotic disorder may be precipitated by severe stress and lasts less than 1 month, but the disorder is defined by delusions, hallucinations, disorganized speech, or grossly disorganized or catatonic behavior. These symptoms are not typical of ASD and should prompt evaluation for primary psychotic, mood, substance-induced, or medical causes.

Mood and Anxiety Disorders

Major depressive disorder, generalized anxiety disorder, panic disorder, and substance use disorders may occur after trauma or coexist with trauma-related symptoms. These diagnoses are favored when the clinical picture is not centered on trauma-related intrusions, avoidance, negative mood, dissociation, and arousal, or when symptoms clearly predate the traumatic event.[7][11]

Borderline Personality Disorder

Borderline personality disorder may include affective instability, dissociation under stress, self-harm, and interpersonal instability. A pervasive pattern beginning by early adulthood, identity disturbance, recurrent abandonment fears, and chronic relationship instability favor borderline personality disorder rather than ASD.

Traumatic Brain Injury and Postconcussive Symptoms

Traumatic brain injury may co-occur with ASD after motor vehicle crashes, assault, falls, blasts, or other traumatic events, but a neurologic injury syndrome is not a direct psychiatric mimic of ASD. A history of head impact, loss or alteration of consciousness, posttraumatic amnesia, worsening headache, repeated vomiting, seizure, focal weakness or numbness, unequal pupils, slurred speech, ataxia, confusion, or progressive somnolence should prompt neurologic assessment and urgent evaluation when danger signs are present. ASD is favored when the dominant symptoms are trauma-cued intrusive memories, avoidance, negative mood, dissociation, and hyperarousal after a qualifying traumatic event.

Substance- or Medication-Induced Symptoms

Intoxication or withdrawal can produce anxiety, insomnia, agitation, perceptual disturbance, derealization, depersonalization, or psychosis. Specific substances to consider include alcohol, sedative-hypnotics and benzodiazepines, cannabis or synthetic cannabinoids, hallucinogens, phencyclidine and related dissociatives such as ketamine, dextromethorphan, stimulants including cocaine and methamphetamine, and prescribed or nonprescribed medications with activating or withdrawal effects. The time course of use or withdrawal, medication review, toxicology testing when clinically indicated, and resolution with abstinence or medical management help distinguish these conditions from ASD.

Specific Medical Conditions

Medical disorders that may present with anxiety, autonomic arousal, insomnia, confusion, dissociation-like symptoms, or panic-like episodes include delirium or toxic-metabolic encephalopathy, hypoglycemia, hyperthyroidism or thyrotoxicosis, adrenal disorders, arrhythmia, acute coronary syndrome, pulmonary embolism, asthma or hypoxia, seizures including temporal lobe epilepsy, central nervous system infection or encephalitis, severe pain, sleep deprivation, medication adverse effects, and medication withdrawal. Vital signs, mental status examination, neurologic examination, medication reconciliation, and targeted laboratory or imaging studies should be guided by the presentation.

Pertinent Studies and Ongoing Trials

Current research has 2 clinical targets. One target is early intervention after trauma to reduce persistent PTSD symptoms. The other is the treatment of established, often chronic PTSD. Clinicians should keep these lines of evidence separate: a positive PTSD treatment trial does not establish an ASD treatment, and an early-intervention protocol does not prove prevention until outcome data are available.

Early Psychotherapy and Implementation Studies

The most consistent guideline-supported ASD intervention remains trauma-focused CBT for patients who already meet ASD criteria.[20] Recent work is testing how to deliver early trauma-focused care in real settings. The Early Intervention in Rape program is evaluating modified prolonged exposure after rape; recent publications support protocol development and feasibility, but the efficacy question remains separate from those early reports.[21][25] Other ongoing studies are testing condensed internet-delivered prolonged exposure and other telehealth or trauma-center models for patients soon after trauma exposure, including the Early Support After Exposure to Trauma trial. A 2025 EAST trauma-surgery guideline review also supports screening trauma patients for PTSD risk and using cognitive behavioral therapy to mitigate later PTSD symptoms when indicated.[26][ClinicalTrials.gov. Early Support After Exposure to Trauma Trial]

Eye movement desensitization and reprocessing: Eye movement desensitization and reprocessing (EMDR) continues to be studied for early posttraumatic symptoms and for PTSD. Results from a 2024 systematic review showed a short-term benefit of early EMDR interventions following recent trauma, but the review emphasized low study quality, small sample sizes, and limited safety data.[23] Results from a 2025 adult PTSD systematic review showed EMDR was effective in several treatment contexts, but most included trials still had small samples and a moderate or high risk of bias.[27] These findings support continued research and selected clinical use by trained clinicians, not a conclusion that EMDR has a proven ASD-prevention effect across trauma populations.

3,4-methylenedioxymethamphetamine–assisted therapy: Two phase 3 trials of 3,4-methylenedioxymethamphetamine (MDMA)–assisted therapy for moderate to severe PTSD reported symptom improvement, but this approach remains investigational and is not United States Food and Drug Administration (FDA)–approved for PTSD or ASD.[28][29] The FDA issued a complete response letter for midomafetamine capsules in August 2024, and the public FDA letter released in September 2025 cited concerns about the reliability of safety data, durability of response, functional unblinding, prior MDMA exposure, and the need for another adequate and well-controlled trial.[FDA. Complete Response Letter] Results from a 2026 meta-analysis showed reductions in PTSD symptoms with MDMA-assisted therapy, but rated the overall certainty of evidence as very low because of small samples, heterogeneity, and blinding limitations.[30] MDMA-assisted therapy has no established role in ASD treatment or prevention.

Other psychedelic or rapid-acting investigational treatments: Psilocybin-assisted therapy is being studied for PTSD, including phase 2 and 3 work with COMP360, but psilocybin-assisted therapy is not approved for PTSD or ASD.[31][ClinicalTrials.gov. A Study Evaluating the Efficacy, Safety, and Tolerability of COMP360 in Participants With Posttraumaic Stress Disorder] Ketamine and esketamine have rapid antidepressant effects in other disorders, but the VA/DoD suggests against ketamine as PTSD monotherapy, and no ketamine-based treatment has an established role for ASD prevention.[20]

Medication augmentation and neuroplastogens: Results from a 2025 phase 3 trial showed that brexpiprazole plus sertraline reduced PTSD symptoms more than sertraline plus placebo.[32] However, the FDA later issued a complete response letter for this PTSD indication, stating that the submitted data did not provide substantial evidence of effectiveness; therefore, the combination is not FDA-approved for PTSD. Results from a 2026 phase 2 PTSD trial showed that TSND-201 (methylone), an investigational neuroplastogen, showed benefit over placebo and is now in phase 3 testing through Empathogen Treatment for Posttraumatic Stress Disorder 1 (EMPOWER-1), but TSND-201 remains investigational and has not been studied as an ASD treatment.[33]

Neuromodulation: Repetitive transcranial magnetic stimulation is being studied for PTSD. Results from a 2026 randomized trial of personalized functional MRI–guided transcranial magnetic stimulation showed improvement in longer-term PTSD symptoms, but VA/DoD guidance still concludes that evidence is insufficient to recommend for or against repetitive transcranial magnetic stimulation for PTSD because protocols, targets, and study populations vary.[20][34] Repetitive transcranial magnetic stimulation has no established role in ASD management.

These studies matter, but they do not change the current ASD treatment message: provide early safety and support, avoid routine debriefing and benzodiazepines, monitor risk over the first month, and offer trauma-focused CBT to patients with diagnosed ASD when available.

Treatment Planning

All treatment plans for ASD should be evidence-based and tailored to the patient's specific needs. The 2023 VA/DoD Clinical Practice Guideline for Posttraumatic Stress Disorder and Acute Stress Disorder provides a practical framework for assessment, early support, trauma-focused psychotherapy, and follow-up.[20]

• Assessment: Confirm exposure to a qualifying traumatic event, evaluate ASD symptom clusters, determine the time since trauma exposure, assess functional impairment, and exclude other diagnoses. Standardized scales, such as the Acute Stress Disorder Scale, may support assessment when needed. A complete safety evaluation, including suicide risk assessment, should be performed.
• Psychoeducation and support: Explain common posttrauma reactions, validate the patient's experience, and provide reassurance about the possibility of recovery. Prioritize safety, promote calming strategies, encourage social connection, and strengthen self-efficacy.[20]
• Watchful waiting and monitoring: Mild, nonimpairing acute stress symptoms may be treated with supportive contact, watchful waiting, and scheduled follow-up, often within 1 to 4 weeks, with earlier reassessment if symptoms worsen or safety concerns emerge.[20]
• Shared decision-making: When ASD causes significant distress or impairment, clinicians should discuss trauma-focused psychotherapy options, including trauma-focused CBT, CPT, prolonged exposure therapy, or EMDR. The discussion should include expected benefits, possible transient symptom intensification, time commitment, and patient preference.
• Psychotherapy initiation: Arrange prompt access to evidence-based psychotherapy when indicated. The treatment format should be individualized, including in-person or telehealth delivery when clinically appropriate.
• Pharmacotherapy discussion: Current guidance does not recommend pharmacotherapy as first-line therapy for ASD or as a routine strategy for PTSD prevention. Benzodiazepines and cannabis or cannabinoid products should be avoided. Medication may be considered only for severe target symptoms or comorbid disorders, such as severe insomnia or major depression, with clear documentation that pharmacotherapy is adjunctive rather than primary ASD treatment.[20]
• Comorbidity management: Assess and treat comorbid depression, anxiety, substance use disorders, pain, sleep disturbance, and traumatic brain injury when present. Comorbidity treatment should occur alongside ASD-focused care.[1]
• Continuity of care: A smooth transition to PTSD-focused evaluation and treatment is needed when symptoms persist beyond 1 month and meet PTSD criteria. Follow-up should monitor symptom trajectory, function, safety, and engagement with care.[20]

Toxicity and Adverse Effect Management

Safe use of recommended psychotherapies and investigational agents requires awareness of potential adverse effects and implementation risks. Potential issues arising from trauma-focused psychotherapies, including trauma-focused cognitive behavioral therapy, cognitive processing therapy, prolonged exposure, and eye movement desensitization and reprocessing, include the following:

• Transient worsening of symptoms: Exposure-based techniques may briefly intensify distress. Clinicians can usually manage this reaction when treatment is paced appropriately and delivered by trained clinicians.
• Dropout: Premature termination may occur because of overwhelming distress, practical barriers, a weak therapeutic alliance, or lack of support.
• Poor implementation risks: Suboptimal training, poor pacing, protocol deviations, or inadequate attention to safety can reduce effectiveness and, in rare cases, worsen symptoms. Clinicians should use appropriate training, supervision, and evidence-based protocols.[20]
• Pharmacotherapy: Because pharmacotherapy is not recommended as primary treatment for ASD, adverse effect monitoring focuses on medications used for severe target symptoms or comorbid disorders. Clinicians should use these agents cautiously and document the target symptom, expected duration, and monitoring plan.[20]
• Benzodiazepines: Clinicians should avoid benzodiazepines in ASD treatment. Risks include dependence, sedation, cognitive impairment, falls, misuse, and possible interference with trauma-focused recovery.[20]
• Cannabis and cannabinoids: Clinicians should not use cannabis or cannabinoids to treat ASD. Potential risks include cognitive impairment, dependence, worsening anxiety, and interference with recovery.[20][24]
• Selective serotonin reuptake inhibitors and serotoninnorepinephrine reuptake inhibitors: When used for significant co-occurring depression or anxiety, standard adverse effects include gastrointestinal adverse effects, sexual dysfunction, sleep disturbance, activation or initial anxiety, discontinuation symptoms, and the need to monitor suicidality in younger individuals.[11]
• Second-generation antipsychotics: If considered adjunctively for severe agitation, psychosis, or treatment-refractory comorbid symptoms, clinicians should monitor for metabolic syndrome, sedation, extrapyramidal symptoms, akathisia, and drug interactions.[20]
• Investigational agents: No pharmacologic or psychedelic intervention is approved for ASD treatment or prevention. Safety profiles are still being characterized in PTSD and related research settings.
• 3,4-methylenedioxymethamphetamine–assisted psychotherapy: Common acute physiologic effects include increased heart rate and blood pressure, muscle tension, nausea, and bruxism. Serious adverse events were uncommon in phase 3 trials, but careful physiologic and psychological monitoring is essential in research settings.[28][29][35]
• Ketamine: Adverse effects may include transient dissociative or perceptual changes, dizziness, nausea or vomiting, and brief elevations in blood pressure and heart rate. Misuse is possible, and caution is needed in the acute posttrauma period.[36][37]
• Psilocybin and other psychedelics: Potential adverse effects include acute anxiety or panic, dysphoria, perceptual disturbance, headache, nausea, and rare, prolonged psychological distress. Clinicians should administer these interventions only in controlled research or specialty settings with appropriate screening and support.[31][38]

Prognosis

The outlook after a traumatic event is variable. Most people experience some distress that remits without formal treatment, whereas a subset develops ASD and remains at increased risk for later PTSD. ASD significantly increases the risk of subsequent PTSD, with conversion rates reported at 50% to 80% in some studies, but ASD is not required for PTSD; many people who later develop PTSD do not meet full ASD criteria during the first month after trauma.[1][4][5] Early identification and treatment, especially trauma-focused psychotherapy when ASD is present and impairing, can reduce symptom burden and may lower the risk of chronic PTSD.[20][21][39]

For patients whose symptoms persist beyond 1 month and meet PTSD criteria, the longitudinal course is different. Many patients recover within months, but a substantial minority develop chronic symptoms that persist for years. Chronic PTSD is associated with functional impairment and high rates of comorbid psychiatric disorders, including depression, anxiety disorders, and substance use disorders.[11]

Long-term symptoms such as avoidance, negative alterations in cognition or mood, and hyperarousal can interfere with social functioning, occupational or academic performance, and quality of life. Avoidant behaviors can contribute to social isolation, occupational difficulty, financial stress, and other psychosocial complications. Stress-related disorders have also been associated with later medical morbidity, including life-threatening infections in population-based data.[40] Clinicians should perform a suicide risk assessment in the acute phase and during follow-up when patients report severe insomnia, agitation, depression, substance use, hopelessness, prior self-harm, or suicidal ideation.

Complications

Potential complications of ASD include progression to PTSD, functional impairment, psychiatric comorbidity, suicidality, and stress-related medical morbidity. Early recognition and follow-up are important because ASD identifies current distress and impairment, even though it does not identify all patients who will later develop PTSD.

• Progression to PTSD: Persistent trauma-related symptoms beyond 1 month may meet diagnostic criteria for PTSD. ASD is associated with increased risk of later PTSD, but the diagnosis is an imperfect predictor; patients with subthreshold acute symptoms may also progress to PTSD.[1][4][5][8]
• Functional impairment and reduced quality of life: ASD symptoms can interfere with interpersonal relationships, family functioning, occupational or academic performance, and quality of life. Functional impairment should be assessed directly because it is a defining feature of clinically significant acute stress reactions and may persist when symptoms evolve into PTSD.[5][11]
• Psychiatric comorbidities: Depression, panic symptoms, generalized anxiety, and substance use disorders may occur after trauma or emerge with later PTSD. Results from systematic reviews after violence-related injury and broader PTSD literature support monitoring for depression, anxiety, and substance use during follow-up.[7][11]
• Suicidality and safety risk: Severe acute stress symptoms, comorbid depression or substance use, prior self-harm, severe insomnia, agitation, hopelessness, and limited support increase clinical concern for suicidal ideation or behavior. Clinicians should perform suicide risk assessment at initial evaluation and during follow-up when risk factors are present.[11]
• Physical health complications: Stress-related disorders and PTSD have been associated with later medical morbidity. Results from population-based studies linked stress-related disorders with increased risk of life-threatening infections, and broader PTSD literature describes adverse health behaviors and physiologic stress pathways that may contribute to medical risk.[40][41][42][43]
• Enduring personality change after catastrophic experience: Enduring personality change after catastrophic experience (EPCACE) is an International Classification of Diseases construct rather than a DSM-5-TR, ASD diagnosis. EPCACE describes persistent personality change after catastrophic stress, including hostile or distrustful attitudes, social withdrawal, emptiness or hopelessness, chronic threat sensitivity, and estrangement. Because EPCACE requires long-term persistence and may follow PTSD, clinicians should frame this condition as a rare and severe long-term posttraumatic outcome rather than an acute ASD complication. A primary objective of early ASD intervention is to reduce downstream complications through prompt recognition, trauma-focused treatment when indicated, risk monitoring, and coordinated interprofessional care.