Acute stress disorder and post-traumatic stress disorder are similar mental health conditions that can develop after a traumatic event. The difference between the two lies in when their symptoms begin.

The American Psychiatric Association (APA) added acute stress disorder (ASD) to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-4) in 1994.

This new condition had similar diagnostic criteria to post-traumatic stress disorder (PTSD) — with a few key differences. For instance, the conditions occur in two separate time frames:

  • ASD occurs within 3–30 days of a traumatic event.
  • PTSD is diagnosed30 days after a traumatic event or later.

And although the two conditions share many symptoms, a PTSD diagnosis requires a broader range of symptoms. An ASD diagnosis requires only a certain number of symptoms overall.

Read on to learn exactly how PTSD and ASD symptoms differ, the potential causes of these conditions, and how to get support.

The symptoms of PTSD fit into four categories:

Re-experiencing the event

Also known as “intrusion,” this can include:


This group of symptoms involves avoiding reminders of the traumatic event. You might keep away from places that remind you of the trauma or avoid activities or people that bring up feelings or thoughts about the trauma.

Changes in thoughts and mood

PTSD can affect the way you think and your overall outlook on life. For example, it can cause:

Reactivity and arousal

Arousal refers to your body’s stress response: fight, flight, or freeze. If you have different levels of arousal or higher reactivity, you might:

ASD is a strong physical and emotional trauma reaction that experts can diagnose before PTSD. It involves the same symptoms as PTSD.

You may also experience these dissociative symptoms:

According to the DSM-5-TR, a diagnosis of ASD requires nine symptoms in all. It also lasts for less than 30 days. If your symptoms linger for a longer period of time, your care team may diagnose PTSD.

The APA created the diagnosis, in fact, to help identify when people had a higher chance of developing PTSD after a traumatic event so they could access support and treatment sooner.

Some people have questioned the usefulness of this diagnosis. After all, ASD doesn’t always predict PTSD, and there’s some concern it could pathologize natural reactions to trauma.

Still, researchers have linked ASD to:

In short, prompt treatment after trauma can make a big difference.

Both ASD and PTSD stem from traumatic events such as:

Still, traumatic events aren’t the only cause of ASD and PTSD. In fact, most people will live through at least one traumatic event in their life, but only 1% to 37% will experience PTSD.

Factors that affect your chances of developing ASD or PTSD include:

  • lack of mental health support
  • personalities higher in neuroticism
  • being female or assigned female at birth
  • coping through avoidance
  • living with another mental health condition
  • having a history of childhood abuse

While certain traumatic events don’t seem to cause one condition more than the other, 2017 research does suggest a stronger link between certain types of trauma, such as direct violence and sexual assault, and PTSD. And 2018 research also suggests trauma type matters when it comes to any trauma-related disorder.

You can’t have ASD and PTSD at the same time, but around 1 in 2 people with ASD will go on to experience PTSD. Some experts have theorized that experiencing more dissociative symptoms could increase your chances of developing PTSD.

Mental health professionals such as psychologists or psychiatrists can diagnose ASD or PTSD. Some people may first connect with a doctor for physical symptoms, such as heart palpitations.

Your care team will use a set of diagnostic criteria, such as the symptoms listed in the DSM-5-TR, to diagnose either condition. They might also ask about:

  • the type of trauma you experienced
  • how recently it happened
  • what symptoms you experience

They may also use screening tools like questionnaires to help diagnose these conditions, such as the Stanford Acute Stress Reaction Questionnaire (SASRQ) and the PTSD Checklist for DSM-5 (PCL-5).

Treatments for ASD and PTSD involve helping you respond to and process trauma. Because the conditions occur at different times, these treatments have some unique aspects.

ASD treatment

Since ASD develops sooner after the traumatic event, treatment may involve mental health care as well as emergency response and support. Examples include:

  • Help with next steps after the traumatic event, such as filing a police report, ensuring access to basic necessities like food and shelter, and medical care if necessary.
  • Forms of therapy such as trauma-focused cognitive behavioral therapy (CBT) or exposure therapy to help prevent PTSD.
  • Support for sleep issues like insomnia, which might involve medications such as prazosin.

Using medication to treat ASD isn’t currently supported by much research, but medications like SSRIs and SNRIs may help ease mood and sleep symptoms.

Treating PTSD

PTSD treatment can include trauma-focused interventions, which address the traumatic memories, along with approaches that address symptoms of the condition. Examples of these treatments include:

Traumatic events can lead to mental health conditions like ASD or PTSD. These conditions can cause symptoms like flashbacks, intrusive thoughts, and sleep problems, but healing is always possible.

Emotional and practical support, as well as therapy and some medications, help many people recover from PTSD. They may also relieve symptoms of ASD and help prevent it from developing into PTSD.

Whether it’s been 2 days or 20 years since the trauma happened, you can always reach out to a compassionate, licensed mental health professional for support and care.