Acute Stress Disorders & PTSD

Ottoline Hart
Author: Ottoline Hart Medical Reviewer: Morgan Blair Last updated:

Acute stress disorder (ASD) and PTSD, an acronym for post-traumatic stress disorder, are debilitating mental health disorders that can develop following traumatic events. Both ASD and PTSD can be treated through psychotherapy and/or medication.

Both PTSD and ASD are classified as anxiety disorders that occur following a traumatic event. They can have a very similar range of symptoms so the most significant area that differentiates these two disorders is the duration and onset of symptoms.

The type of events that can cause PTSD or ASD include those pertaining to violence, death, sexual assault, serious injury or an event threatening one’s core physical or emotional needs. One does not have to be at the center of these events to experience PTSD or ASD but can also be a witness to any of these stressors affecting other people.

What is acute stress disorder?

Acute stress disorder is a shorter-term mental health illness that classifies those symptoms that occur immediately after a traumatic incident and lasts for a much shorter duration than PTSD (a maximum of 28 days).

Symptoms must persist for more than 3 days and they tend to onset very quickly after the stressful event. Symptoms must be disruptive to several areas of one’s life to qualify as acute stress disorder.

The diagnosis acute stress disorder was developed to distinguish earlier onset of symptoms following a traumatic event so that these could be brought to attention and treated by doctors or therapists right away.

Early intervention is key is because those with acute stress disorder are most at risk of developing PTSD and thus the earlier diagnosis and consequential treatment was established to try and prevent the development of PTSD [1].

What is PTSD?

PTSD is a severe and life-changing illness. This disorder refers to the development of impairing symptoms at least 30 days after experiencing a traumatic event.

Symptoms reflect those of ASD, but to be diagnosed with PTSD the symptoms must continue for at least a month following a traumatic event. Symptoms may also appear months or year later if an individual’s experiences trigger previously repressed memories.   

PTSD can affect many areas of the patient’s life including the way they interact with the world socially, professionally and their sense of self. PTSD should ideally be treated by trauma-focused experts.

Acute stress disorder vs PTSD: Symptoms

According to The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, otherwise known as the DSM-V, both acute stress disorder and PTSD have the same range of symptoms. Both disorders cause distress or functional impairment to various areas of one’s life.

As mentioned earlier, the only key differences are the onset and duration of symptoms where ASD affects the person very quickly following the trauma and lasts up to 28 days, whilst PTSD must last for longer than a month and symptoms can onset much later, even years later.

Below are the symptoms as listed in the DSM-V:

  • The person in question had either direct exposure to the trauma, witnessed the trauma, learned that a direct friend or relative were subject to the trauma, or had indirect exposure to aversive details of the trauma.
  • The person in question re experiences unwanted images of the traumatic event whether through recurring thoughts, flashbacks, nightmares, unwanted upsetting memories, intense emotional distress when coming across reminders of the traumatic incident, or physical reactivity to reminders of the traumatic incident.
  • Avoidance of any trauma related thoughts, feelings or reminders of the incident.
  • At least 2 of the following negative feelings that began or worsened following the traumatic incident:
  • Inability to remember key features of the traumatic incident
  • Overly negative thoughts or assumptions about oneself or the world
  • Exaggerated blame or self or others for causing the trauma
  • Negative affect
  • Less joy or motivation or interest in usual activities
  • Feelings of loneliness or isolation
  • Struggle to experience positivity
  • At least two of the following ways in which emotional arousal and reactivity began or worsened after the trauma:
  • Irritability or aggression
  • Risky or destructive behavior
  • Hypervigilance
  • Heightened startle reaction
  • Difficulty concentrating
  • Difficulty sleeping 

Further specifications are also included in the DSM-V for delayed symptoms (where full diagnostic criteria of PTSD does not onset until 6 months), as well as for dissociation. The dissociation specification includes sections on both derealization (experiences of unreality, distance or distortion ie the feeling that “things are not real”) and depersonalization (experience of being an outside observer or detached from oneself ie “things are not happening to me” or as if one were in a dream). [2]

Acute stress disorder vs PTSD: Causes

Acute stress disorder and PTSD are ways in which the body and mind react to a traumatic or life-threatening event. Many people can experience the same life-threatening event and have very different reactions. Not everyone will develop ASD or PTSD.

When we experience or witness an event that we perceive is life threatening, our amygdala, which acts like the body’s emergency alarm system, sounds off to indicate to our body of immediate danger. When this happens our bodies release stress hormones. More blood is pumped into our heart increasing our heart rate and alertness. All our bodily functions that aren’t necessary for this fight or flight function, such as the digestive system, are bypassed so that our bodies can focus on dealing with the immediate danger.

Cortisol levels are heightened until danger is perceived as being over. When the threat subsides, the body should then put the brakes by triggering the parasympathetic nervous system to relax again, and for cortisol and adrenaline levels to fall.

Unfortunately, in some cases even once the traumatic incident is over the body can maintain this stress response. When our stress levels persist in this way, it can lead to the development of ASD or PTSD.

It is not known exactly why some people develop PTSD or ASD following an event, while others who were present at the same event don’t, but researchers have some thoughts. There is research to suggest a correlation between a prolonged stress response and a lack of agency during the traumatic event. A lack of agency can look like an inability to run away or defend oneself.[3]

Acute stress disorder vs PTSD: Treatment

Acute stress disorder and PTSD can both be treated through a variety of medication and psychological therapies. Medications to treat these conditions include antidepressants, antipsychotics, and mood stabilizers.

The leading medication recommendations are SSRIs, a type of antidepressant. There is some evidence to suggest that they can help to relieve the core symptoms including: re-experiencing the trauma (through flashbacks, nightmares etc), hyperarousal and avoidance/numbing [1].

Benzodiazepines have been used and there is evidence to show that they can relieve some of the symptoms following a traumatic incidence. However, side effects including dependence, higher incidence, and even worsening of PTSD symptoms following withdrawal, mean that they are not recommended to be used alone or as a main medication.

It is important that the patient speaks with someone who is specialized in trauma in order to get the most effective treatment possible for their particular symptoms. Of those psychotherapeutic interventions that have had the funds and support to finance trialing on a large scale, the ones that have been found to be the most effective treatments of choice are TFCBT (Trauma Focused Cognitive Behavioral Therapy), CBT (Cognitive Behavioral Therapy), and EMDR (Eye Movement Desensitization and Reprocessing) [4].

There is evidence to suggest that CBT 2-3 weeks following a traumatic incident can speed up recovery and reduce the likelihood of developing PTSD. On the other hand, there is evidence to suggest that psychological debriefing following a traumatic incident can be harmful and is not recommended.[1]

Usually someone who has experienced a traumatic event tends to process the incident naturally over around 4 to 12 weeks [3]. However, if someone is exhibiting symptoms of acute stress disorder, it is very important to treat it quickly and effectively to give the patient the coping mechanisms needed. As much as possible should be done to support the patient so that they do not develop PTSD, which can have debilitating and lifelong consequences.

Can you have PTSD and ASD at the same time?

You cannot have both PTSD and ASD at the same time. If symptoms remain after 28 days following a traumatic incident, an ASD diagnosis would turn into a PTSD diagnosis.

Following extensive research, there is a great deal of evidence discovered that shows that 80% of those who have an ASD diagnosis will go on to develop PTSD. Furthermore, around 4-13% of those who do not experience ASD can still develop PTSD later on. [5]

  1. Ursano, R. J., Bell, C., Eth, S., Friedman, M., Norwood, A., Pfefferbaum, B., Pynoos, J. D., Zatzick, D. F., Benedek, D. M., McIntyre, J. S., Charles, S. C., Altshuler, K., Cook, I., Cross, C. D., Mellman, L., Moench, L. A., Norquist, G., Twemlow, S. W., Woods, S., Yager, J., … Steering Committee on Practice Guidelines (2004). Practice guideline for the treatment of patients with acute stress disorder and posttraumatic stress disorder. The American journal of psychiatry, 161(11 Suppl), 3–31.
  2. American Psychiatric Association. (2013) Diagnostic and statistical manual of mental disorders, (5th ed.). Washington, DC: Author.
  3. Cahill, S. P., & Pontoski, K. (2005). Post-traumatic stress disorder and acute stress disorder I: their nature and assessment considerations. Psychiatry (Edgmont (Pa. : Township)), 2(4), 14–25.
  4. Bisson, J. I., Roberts, N. P., Andrew, M., Cooper, R., & Lewis, C. (2013). Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. The Cochrane database of systematic reviews, 2013(12), CD003388.
  5. Bryant, R. A. (2011). Acute stress disorder as a predictor of posttraumatic stress disorder: A systematic review. The Journal of Clinical Psychiatry, 72, 233-239. doi:10.4088/JCP.09r05072blu
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Ottoline Hart
Author Ottoline Hart Writer

Ottoline Hart is a medical writer and psychotherapist with a background in Integrative Psychotherapy from the University of Oxford.

Published: Feb 14th 2023, Last edited: Sep 22nd 2023

Morgan Blair
Medical Reviewer Morgan Blair MA, LPCC

Morgan Blair is a licensed therapist, writer and medical reviewer, holding a master’s degree in clinical mental health counseling from Northwestern University.

Content reviewed by a medical professional. Last reviewed: Feb 14th 2023