Post-traumatic stress syndrome (PTSS) refers to symptoms that occur in the immediate aftermath of a traumatic event. Post-traumatic stress disorder (PTSD) refers to symptoms that occur at least 1 month later.

Another name for PTSS is acute stress disorder, which can be a precursor to PTSD, but not always. Most people who experience traumatic events recover in time, with only some going on to develop PTSD.

Sometimes, it can take months or years for PTSD to develop or for a person to meet the full diagnostic criteria.

Read on to learn more about PTSS versus PTSD, including the differences, symptoms, causes, and treatments.

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PTSS, or acute stress disorder (ASD), is a cluster of mental health symptoms that can occur within 30 days of a traumatic event.

In contrast, PTSD is a condition that medical professionals can diagnose at least 1 month after a traumatic event.

Both conditions can cause anxiety, intrusive memories, difficulty sleeping, and other symptoms. Because of the similarities, the main difference between PTSS and PTSD is in their timing and duration. Some sources also suggest that PTSS is less severe than PTSD.

However, in a 2023 study, 20% of trauma survivors with PTSS reported severe symptoms. Additionally, 40% had moderate symptoms, 30% had mild symptoms, and 10% reported minimal symptoms.

The potential symptoms of PTSS and PTSD are the same. However, the frequency, severity, and likelihood of symptoms may vary.

The symptoms of both PTSD and PTSS include:

  • intrusive memories of the traumatic event
  • intense distress when encountering reminders of the traumatic event
  • nightmares
  • difficulty sleeping
  • reexperiencing the event in the form of flashbacks, which could be visual, sensory, or emotional
  • periods of dissociation, which is when a person feels disconnected from themselves or reality
  • difficulty remembering details of the event
  • hypervigilance, or always feeling “on edge”
  • being easily startled
  • irritability or a quick temper
  • persistent negative emotions, such as guilt, anger, sadness, or shame
  • difficulty experiencing positive emotions, such as contentment or love
  • difficulty concentrating
  • reduced interest in things a person used to enjoy
  • reckless or self-destructive behavior
  • avoidance of places and stimuli relating to the event

A person does not have to have every symptom to have PTSS or PTSD. The main symptoms integral to a PTSD diagnosis are:

  • reexperiencing the event through intrusive thoughts, dreams, or flashbacks
  • negative changes in mood
  • changes in reactivity and arousal
  • avoidance of reminders
  • onset or continuation of symptoms at least 1 month after the event

Research suggests that most people with PTSS may have mild or moderate symptoms, while only some report severe symptoms.

No, they are distinct diagnoses. PTSS is a reaction to trauma that develops fairly quickly, while PTSD occurs months or sometimes years later.

However, PTSS has a different name in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). In this text, PTSS is known as acute stress disorder, which clinicians typically use.

Experiencing events that a person perceives as dangerous or threatening is what causes these conditions.

The event could be a one-off incident, a series of incidents, or an ongoing experience, such as living in an unsafe area. The danger could also affect a person directly, or the individual may witness or learn how it affects others.

Some examples of potentially traumatic experiences include but are not limited to:

  • experiencing assault
  • being in a warzone
  • having a severe illness or injury
  • undergoing childbirth

Not everyone who experiences traumatic events develops symptoms. Additionally, not everyone experiences both PTSS and then PTSD. Some may have a delayed reaction to a traumatic event, while others only experience PTSS and then recover.

However, having PTSS, particularly if the symptoms are severe, is a risk factor for developing PTSD.

PTSS can resolve on its own. For this reason, most research on treatment focuses on PTSD.

The main treatment options for PTSD include:

Learn more about the different types of therapy.

Does treating PTSS prevent PTSD?

There are differing opinions in the medical community about whether early treatment of PTSS could prevent PTSD. Some sources claim early intervention is important, but a 2021 review of previous research found that there is currently a lack of evidence.

However, the researchers found evidence that CBT may help people who have significant PTSS or ASD symptoms. This may suggest that treating people with severe symptoms, as opposed to everyone, may help those most at risk for PTSD.

Another 2021 review of people who experienced traumatic childbirth also found that early intervention helped reduce psychological symptoms after 4 to 6 weeks. However, the researchers point out that studies with longer follow-up times are necessary.

Both PTSS and PTSD can get better, either on their own or with treatment.

PTSS can be a temporary response to a recent stressor. Over time, and especially with support, PTSS symptoms may improve. Most people recover after a traumatic event.

In some people, PTSS can become PTSD, or they may develop PTSD after having a delayed reaction to the event. In this case, treatment may be necessary. People with PTSD who seek treatment tend to have more positive outcomes. With help from an experienced trauma therapist, recovery is possible.

Read more about PTSD support groups and resources.

Anyone who believes they may have PTSD needs to seek help from a doctor or mental health professional. This is especially important if the symptoms:

  • interfere with the ability to work or have healthy relationships
  • prevent a person from doing daily tasks, such as washing or eating
  • cause themselves, or loved ones, to worry about their mental state
  • lead to harmful behaviors, such as substance misuse
  • include thoughts of self-harm

Those with PTSS may wish to seek support from understanding friends, family, or support organizations for the type of traumatic event they experienced. Social support is a key factor that may help protect against PTSD.

If the symptoms are severe, those with PTSS may also benefit from speaking with a mental health professional. Anyone with very severe symptoms needs to seek help immediately, whatever the cause.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

Was this helpful?

Both post-traumatic stress syndrome (PTSS) and post-traumatic stress disorder (PTSD) are reactions to trauma and can have similar symptoms. However, PTSS occurs in the aftermath of a traumatic event within 30 days. PTSD is when symptoms develop after this point.

Health professionals refer to PTSS as acute stress disorder. The symptoms can improve over time, but anyone with persistent or severe symptoms needs to seek help. PTSD is treatable, and having the right support can significantly improve a person’s quality of life.