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Apex Nursing

Chart — Mental Health

Acute Stress Disorder vs PTSD

Same trauma response, different clock. Acute stress disorder runs from 3 days to 1 month after the event; once symptoms persist beyond a month, it is PTSD.

Educational use only. Diagnosis and trauma-focused therapy are provider-directed. This chart is an educational comparison aid. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.

Side by Side

FeatureAcute stress disorderPTSD
TriggerExposure to actual/threatened death, serious injury, or sexual violenceSame — experienced, witnessed, or learned of
Onset / timingSymptoms begin and last 3 DAYS to 1 MONTH after the eventSymptoms persist LONGER than 1 month (may begin later — delayed onset)
Symptom clustersIntrusion, avoidance, negative mood, dissociation, arousalIntrusion, avoidance, negative cognition/mood, hyperarousal (4 clusters)
DissociationOften prominent (numbing, derealization, amnesia)May occur; not required
RelationshipCan resolve, or progress to PTSD if symptoms persist past 1 monthThe persistent disorder; often preceded by ASD
First-line treatmentTrauma-focused CBT; psychological first aid; usually no benzodiazepinesTrauma-focused psychotherapy (CPT, PE, EMDR) + SSRIs/SNRIs; prazosin for nightmares; avoid benzodiazepines

Exam Traps

  • The discriminator is TIME: ASD = 3 days to 1 month; PTSD = symptoms lasting more than 1 month.
  • Both share the same trauma response and overlapping symptoms; ASD can progress to PTSD.
  • The four PTSD clusters: intrusion/re-experiencing, avoidance, negative cognition/mood, hyperarousal.
  • PTSD meds: SSRIs/SNRIs first-line; prazosin for nightmares; benzodiazepines are generally avoided.
  • During a flashback (either disorder): keep the patient safe and ground/orient to the present.
  • Always screen for suicide and substance use — both commonly co-occur.

Related Resources

Standards & sources

Fact-checked Jun 21, 2026

This page is written to align with American Psychiatric Association (DSM-5-TR) · American Psychiatric Nurses Association (APNA) · SAMHSA. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →